I was trying out Navigation architecture component and is now having difficulties in setting the title. How do I set the title programmatically and also how it works?

To clear my question, let&#39;s have an example, where, I&#39;ve set up a simple app with `MainActivity` hosting the navigation host controller, the `MainFragment` has a button and on clicking the button it goes to `DetailFragment`.

The same code from another question of [multiple app bars][1] on stack-overflow.

**MainActivity**

    public class MainActivity extends AppCompatActivity {
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            Toolbar toolbar = findViewById(R.id.toolbar);
            setSupportActionBar(toolbar);

            // Setting up a back button
            NavController navController = Navigation.findNavController(this, R.id.nav_host);
            NavigationUI.setupActionBarWithNavController(this, navController);
        }
    
        @Override
        public boolean onSupportNavigateUp() {
            return Navigation.findNavController(this, R.id.nav_host).navigateUp();
        }
    }

**MainFragment**

    public class MainFragment extends Fragment {
    
        public MainFragment() {
            // Required empty public constructor
        }
    
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            // Inflate the layout for this fragment
            return inflater.inflate(R.layout.fragment_main, container, false);
        }
    
        @Override
        public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
            super.onViewCreated(view, savedInstanceState);
            Button buttonOne = view.findViewById(R.id.button_one);
            buttonOne.setOnClickListener(Navigation.createNavigateOnClickListener(R.id.detailFragment));
        }
    
    }

**DetailFragment**

    public class DetailFragment extends Fragment {
    
        public DetailFragment() {
            // Required empty public constructor
        }
    
        @Override
        public void onCreate(@Nullable Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
        }
    
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            // Inflate the layout for this fragment
            return inflater.inflate(R.layout.fragment_detail, container, false);
        }
    }

**activity_main.xml**

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
        xmlns:app=&quot;http://schemas.android.com/apk/res-auto&quot;
        xmlns:tools=&quot;http://schemas.android.com/tools&quot;
        android:layout_width=&quot;match_parent&quot;
        android:layout_height=&quot;match_parent&quot;
        android:animateLayoutChanges=&quot;true&quot;
        tools:context=&quot;.MainActivity&quot;&gt;
    
        &lt;com.google.android.material.appbar.AppBarLayout
            android:layout_width=&quot;match_parent&quot;
            android:layout_height=&quot;wrap_content&quot;
            android:animateLayoutChanges=&quot;true&quot;
            android:theme=&quot;@style/AppTheme.AppBarOverlay&quot;&gt;
    
            &lt;androidx.appcompat.widget.Toolbar
                android:id=&quot;@+id/toolbar&quot;
                android:layout_width=&quot;match_parent&quot;
                android:layout_height=&quot;?attr/actionBarSize&quot;
                android:background=&quot;?attr/colorPrimary&quot;
                app:popupTheme=&quot;@style/AppTheme.PopupOverlay&quot; /&gt;
    
        &lt;/com.google.android.material.appbar.AppBarLayout&gt;
    
        &lt;fragment
            android:id=&quot;@+id/nav_host&quot;
            android:name=&quot;androidx.navigation.fragment.NavHostFragment&quot;
            android:layout_width=&quot;match_parent&quot;
            android:layout_height=&quot;match_parent&quot;
            android:layout_gravity=&quot;top&quot;
            android:layout_marginTop=&quot;?android:attr/actionBarSize&quot;
            app:defaultNavHost=&quot;true&quot;
            app:layout_anchor=&quot;@id/bottom_appbar&quot;
            app:layout_anchorGravity=&quot;top&quot;
            app:layout_behavior=&quot;@string/appbar_scrolling_view_behavior&quot;
            app:navGraph=&quot;@navigation/mobile_navigation&quot; /&gt;
    
        &lt;com.google.android.material.bottomappbar.BottomAppBar
            android:id=&quot;@+id/bottom_appbar&quot;
            android:layout_width=&quot;match_parent&quot;
            android:layout_height=&quot;?android:attr/actionBarSize&quot;
            android:layout_gravity=&quot;bottom&quot; /&gt;
    
        &lt;com.google.android.material.floatingactionbutton.FloatingActionButton
            android:id=&quot;@+id/fab&quot;
            android:layout_width=&quot;wrap_content&quot;
            android:layout_height=&quot;wrap_content&quot;
            app:layout_anchor=&quot;@id/bottom_appbar&quot; /&gt;
    
    &lt;/androidx.coordinatorlayout.widget.CoordinatorLayout&gt;

**navigation.xml**

    &lt;navigation xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
        xmlns:app=&quot;http://schemas.android.com/apk/res-auto&quot;
        xmlns:tools=&quot;http://schemas.android.com/tools&quot;
        android:id=&quot;@+id/mobile_navigation&quot;
        app:startDestination=&quot;@id/mainFragment&quot;&gt;
        &lt;fragment
            android:id=&quot;@+id/mainFragment&quot;
            android:name=&quot;com.example.MainFragment&quot;
            android:label=&quot;fragment_main&quot;
            tools:layout=&quot;@layout/fragment_main&quot; &gt;
            &lt;action
                android:id=&quot;@+id/toAccountFragment&quot;
                app:destination=&quot;@id/detailFragment&quot; /&gt;
        &lt;/fragment&gt;
        &lt;fragment
            android:id=&quot;@+id/detailFragment&quot;
            android:name=&quot;com.example.DetailFragment&quot;
            android:label=&quot;fragment_account&quot;
            tools:layout=&quot;@layout/fragment_detail&quot; /&gt;
    &lt;/navigation&gt;

So when start my app, **the title is &quot;MainActivity&quot;**. As usual it shows the `MainFragment` that contains the button to go to `DetailFragment`. In the `DialogFragment` I&#39;ve set the title as:

    getActivity().getSupportActionBar().setTitle(&quot;Detail&quot;);

**First Problem:** So clicking the button on the `MainFragment` to goto `DetailFragment`, it does go there and the title changes to &quot;Detail&quot;. But on clicking the back button, the **title changes to &quot;fragment_main&quot;**. So I added this line of code to `MainFragment`:

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        // ...

        //Showing the title 
        Navigation.findNavController(view)
          .getCurrentDestination().setLabel(&quot;Hello&quot;);
    }

Now the while returning back from `DetailFragment` to `MainFragment` the title changes to &quot;Hello&quot;. But here comes the **second problem**, when I close the app and start again, the title changes back to &quot;MainActivity&quot; though it should be showing &quot;Hello&quot; instead, know?

Ok, then adding `setTitle(&quot;Hello&quot;)` in `MainFrgment` is not working too. For example, the activity starts and the title is &quot;Hello&quot;, go to `DetailsFragment` and press the back button again, the title goes back to &quot;fragment_main&quot;.

The only solution is to have both `setTitle(&quot;Hello&quot;)` along with `Navigation.findNavController(view).getCurrentDestination().setLabel(&quot;Hello&quot;)` in `MainFragment`.

So what is the proper way to show the title for fragments using Navigation Component?

  [1]: https://stackoverflow.com/questions/52483927/two-different-menus-for-top-app-bar-and-bottom-app-bar-with-navigation-component


How to set title in app bar with Navigation Architecture Component

I have tried below code but it reflects nothing in the UI, I&#39;m missing anything here?

    class MainActivity : AppCompatActivity() {
    
        override fun onCreate(savedInstanceState: Bundle?) {
            super.onCreate(savedInstanceState)
            setContent {
                loadUi()
            }
        }
        
        @Composable
        fun loadUi() {
            CraneWrapper {
                MaterialTheme {
                    Image(
                        (ResourcesCompat.getDrawable(
                            resources,
                            R.mipmap.ic_launcher,
                            null
                        ) as BitmapDrawable).bitmap
                    )
                }
            }
        }
    }

How to load Image from drawable in Jetpack compose?

I am reading about a room library of Android. I see they changed package `android` to `androidx`. I did not understand that. Can someone explain, please?

    implementation &quot;androidx.room:room-runtime:$room_version&quot;
    annotationProcessor &quot;androidx.room:room-compiler:$room_version&quot;

Even this is available with the `android` package also.

    implementation &quot;android.arch.persistence.room:runtime:$room_version&quot;
    annotationProcessor &quot;android.arch.persistence.room:compiler:$room_version&quot;


 - What was in need of packaging new support libraries in `androidx` instead of `android`?
 - Use case and affect factors in existing projects.


What is AndroidX?

Hi I&#39;m new to Android development and I&#39;m trying out a tutorial on MVVM I found on YouTube. The example project in the video uses AppCompat but I converted mine to androidx because from what I read its the current(?) version to use? Am I mistaken with this thinking?

Anyways Part of the tutorial makes use of a RecyclerView and I can&#39;t access it on my activity_main.xml file stating that v7 is an unresolved package. `android.support.v7.widget.RecyclerView` shows up with v7 onwards as red text. I know I can revert it back to older versions but I guess I am trying to make this work since moving forward its expected to know how to use androidx right? 

I don&#39;t know how to add the RecyclerView to the project with my current project migrated to androidx.

**What I&#39;ve tried:**

* Adding `implementation &#39;com.android.support:recyclerview-v7:28.0.0&#39;` based on the docs
* Invalidating cache and restarting

**My Dependencies:**
```
dependencies {
    implementation fileTree(dir: &#39;libs&#39;, include: [&#39;*.jar&#39;])
    implementation &#39;androidx.appcompat:appcompat:1.1.0-alpha04&#39;
    implementation &#39;androidx.appcompat:appcompat:1.0.0-beta01&#39;
    implementation &#39;androidx.cardview:cardview:1.0.0&#39;
    implementation &#39;androidx.constraintlayout:constraintlayout:1.1.3&#39;
    testImplementation &#39;junit:junit:4.12&#39;
    androidTestImplementation &#39;androidx.test:runner:1.1.0-alpha4&#39;
    androidTestImplementation &#39;androidx.test.espresso:espresso-core:3.1.0-alpha4&#39;

    //RecyclerView
    implementation &#39;com.android.support:recyclerview-v7:28.0.0&#39;


    // Lifecycle components
    implementation &quot;androidx.lifecycle:lifecycle-extensions:2.1.0-alpha04&quot;
    annotationProcessor &quot;androidx.lifecycle:lifecycle-compiler:2.1.0-alpha04&quot;

    // Room Components
    implementation &quot;androidx.room:room-runtime:2.1.0-alpha06&quot;
    annotationProcessor &quot;androidx.room:room-compiler:2.1.0-alpha06&quot;
}
```

**My activity_main.xml**

```
&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
&lt;androidx.constraintlayout.widget.ConstraintLayout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
    xmlns:app=&quot;http://schemas.android.com/apk/res-auto&quot;
    xmlns:tools=&quot;http://schemas.android.com/tools&quot;
    android:layout_width=&quot;match_parent&quot;
    android:layout_height=&quot;match_parent&quot;
    tools:context=&quot;.MainActivity&quot;&gt;

    &lt;view class=&quot;android.support.v7.widget.RecyclerView&quot;
        android:id=&quot;@+id/recycler_view&quot;
        android:layout_width=&quot;match_parent&quot;
        android:layout_height=&quot;match_parent&quot;
        tools:listitem=&quot;@layout/todo_item&quot;/&gt;

&lt;/androidx.constraintlayout.widget.ConstraintLayout&gt;
```

How to access RecyclerView in androidx?

How to set [RecyclerView][1] layoutManager from XML? 

        &lt;android.support.v7.widget.RecyclerView
            app:layoutManager=&quot;???&quot;
            android:layout_width=&quot;match_parent&quot;
            android:layout_height=&quot;match_parent&quot;/&gt;


  [1]: http://developer.android.com/intl/zh-tw/reference/android/support/v7/widget/RecyclerView.html

How to set RecyclerView app:layoutManager=&quot;&quot; from XML?

I&#39;m using **Android Studio 3.2 Beta5** to migrate my project to **AndroidX**. When I rebuild my app I got these errors:

&gt; ERROR: [TAG] Failed to resolve variable &#39;${animal.sniffer.version}&#39;
&gt;
&gt; ERROR: [TAG] Failed to resolve variable &#39;${junit.version}&#39;

Full clean &amp; rebuild did not work! Anyone know how to fix this?  

---


**gradle.properties**

    android.enableJetifier=true
    android.useAndroidX=true

**build.gradle**
    
    buildscript {
        repositories {
            google()
            jcenter()
            mavenCentral()
            maven { url &#39;https://maven.fabric.io/public&#39; }
            maven { url &quot;https://oss.sonatype.org/content/repositories/snapshots&quot; }
        }
        dependencies {
            classpath &#39;com.android.tools.build:gradle:3.2.0-beta05&#39;
    
            classpath &#39;com.google.gms:google-services:4.0.1&#39;
            classpath &quot;io.realm:realm-gradle-plugin:5.3.1&quot;
            classpath &#39;io.fabric.tools:gradle:1.25.4&#39;
            classpath &#39;com.google.firebase:firebase-plugins:1.1.5&#39;
        }
    }
    
    allprojects {
        repositories {
            google()
            jcenter()
            mavenCentral()
            maven { url &quot;https://oss.sonatype.org/content/repositories/snapshots&quot; }
        }
    }
    
    task clean(type: Delete) {
        delete rootProject.buildDir
    }

**app/build.gradle**

    apply plugin: &#39;com.android.application&#39;
    apply plugin: &#39;realm-android&#39;
    apply plugin: &#39;io.fabric&#39;
    apply plugin: &#39;com.google.firebase.firebase-perf&#39;
    
    android {
        compileSdkVersion 28
        buildToolsVersion &quot;28.0.0&quot;
        defaultConfig {
            applicationId &quot;com.iceteaviet.fastfoodfinder&quot;
            minSdkVersion 16
            targetSdkVersion 28
            versionCode 1
            versionName &quot;1.0&quot;
            multiDexEnabled true
        }
    
        buildTypes {
            release {
                minifyEnabled false
                proguardFiles getDefaultProguardFile(&#39;proguard-android.txt&#39;), &#39;proguard-rules.pro&#39;
            }
            debug {
            }
        }
        aaptOptions {
            cruncherEnabled = false
        }
    }
    
    dependencies {
        implementation fileTree(include: [&#39;*.jar&#39;], dir: &#39;libs&#39;)
        testImplementation &#39;junit:junit:4.12&#39;
    
        implementation &#39;com.jakewharton:butterknife:9.0.0-SNAPSHOT&#39;
    
        implementation &#39;androidx.appcompat:appcompat:1.0.0-rc01&#39;
        implementation &#39;com.google.android.material:material:1.0.0-rc01&#39;
        implementation &#39;androidx.legacy:legacy-support-v4:1.0.0-rc01&#39;
        implementation &#39;androidx.cardview:cardview:1.0.0-rc01&#39;
    
        implementation &#39;com.google.maps.android:android-maps-utils:0.5&#39;
        implementation &#39;com.google.android.gms:play-services-maps:15.0.1&#39;
        implementation &#39;com.google.android.gms:play-services-location:15.0.1&#39;
        implementation &#39;com.google.firebase:firebase-core:16.0.1&#39;
        implementation &#39;com.google.firebase:firebase-database:16.0.1&#39;
        implementation &#39;com.google.firebase:firebase-auth:16.0.1&#39;
        implementation &#39;com.google.android.gms:play-services-auth:15.0.1&#39;
    
        implementation &#39;com.github.bumptech.glide:glide:4.7.1&#39;
    
        implementation &#39;com.google.code.gson:gson:2.8.5&#39;
        implementation &#39;com.squareup.retrofit2:retrofit:2.4.0&#39;
        implementation &#39;com.squareup.retrofit2:converter-gson:2.4.0&#39;
    
        implementation &#39;org.greenrobot:eventbus:3.1.1&#39;
    
        implementation &#39;de.hdodenhof:circleimageview:2.2.0&#39;
    
        implementation &#39;io.realm:realm-android-library:5.3.1&#39;
    
        implementation &#39;com.facebook.android:facebook-android-sdk:4.34.0&#39;
    
        implementation &#39;io.reactivex.rxjava2:rxandroid:2.0.2&#39;
        implementation &#39;io.reactivex.rxjava2:rxjava:2.0.2&#39;
    
        implementation &#39;androidx.multidex:multidex:2.0.0&#39;
    
        implementation &#39;com.crashlytics.sdk.android:crashlytics:2.9.4&#39;
        implementation &#39;com.google.firebase:firebase-perf:16.0.0&#39;
    
        implementation &#39;com.jakewharton.timber:timber:4.7.1&#39;
    
        annotationProcessor &#39;com.jakewharton:butterknife-compiler:9.0.0-SNAPSHOT&#39;
        annotationProcessor &#39;com.github.bumptech.glide:compiler:4.7.1&#39;
    }
    
    apply plugin: &#39;com.google.gms.google-services&#39;



Failed to resolve variable &#39;${animal.sniffer.version}&#39; when migrate to AndroidX

I am developing a news app but I am getting following errors in from gradle console

    (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
    Duplicate class android.support.v4.app.INotificationSideChannel$Stub found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
    Duplicate class android.support.v4.app.INotificationSideChannel$Stub$Proxy found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
    Duplicate class android.support.v4.graphics.drawable.IconCompatParcelizer found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
    Duplicate class android.support.v4.os.IResultReceiver found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
    Duplicate class android.support.v4.os.IResultReceiver$Stub found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
    Duplicate class android.support.v4.os.IResultReceiver$Stub$Proxy found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
    Duplicate class android.support.v4.os.ResultReceiver found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
    Duplicate class android.support.v4.os.ResultReceiver$1 found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
    Duplicate class android.support.v4.os.ResultReceiver$MyResultReceiver found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
    Duplicate class android.support.v4.os.ResultReceiver$MyRunnable found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
    Duplicate class androidx.core.graphics.drawable.IconCompatParcelizer found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
    Duplicate class androidx.core.internal.package-info found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:28.0.0)
    Duplicate class androidx.versionedparcelable.CustomVersionedParcelable found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
    Duplicate class androidx.versionedparcelable.NonParcelField found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
    Duplicate class androidx.versionedparcelable.ParcelField found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
    Duplicate class androidx.versionedparcelable.ParcelImpl found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
    Duplicate class androidx.versionedparcelable.ParcelImpl$1 found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
    Duplicate class androidx.versionedparcelable.ParcelUtils found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
    Duplicate class androidx.versionedparcelable.VersionedParcel found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
    Duplicate class androidx.versionedparcelable.VersionedParcel$1 found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
    Duplicate class androidx.versionedparcelable.VersionedParcel$ParcelException found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
    Duplicate class androidx.versionedparcelable.VersionedParcelParcel found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
    Duplicate class androidx.versionedparcelable.VersionedParcelStream found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
    Duplicate class androidx.versionedparcelable.VersionedParcelStream$FieldBuffer found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
    Duplicate class androidx.versionedparcelable.VersionedParcelStream$InputBuffer found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
    Duplicate class androidx.versionedparcelable.VersionedParcelable found in modules classes.jar (androidx.versionedparcelable:versionedparcelable:1.0.0) and classes.jar (com.android.support:versionedparcelable:28.0.0)
    Duplicate class androidx.versionedparcelable.VersionedParcelize found in modules class

below my app.gradle

&lt;!-- language: groovy --&gt;

    apply plugin: &#39;com.android.application&#39;
    
    android {
        compileSdkVersion 28
        defaultConfig {
            applicationId &quot;com.example.myapplication&quot;
            minSdkVersion 15
            targetSdkVersion 28
            versionCode 1
            versionName &quot;1.0&quot;
            testInstrumentationRunner &quot;android.support.test.runner.AndroidJUnitRunner&quot;
        }
        buildTypes {
            release {
                minifyEnabled false
                proguardFiles getDefaultProguardFile(&#39;proguard-android-optimize.txt&#39;), &#39;proguard-rules.pro&#39;
            }
        }
    }
    
    dependencies {
        implementation fileTree(dir: &#39;libs&#39;, include: [&#39;*.jar&#39;])
        implementation &#39;com.android.support:appcompat-v7:28.0.0&#39;
        implementation &#39;com.android.support.constraint:constraint-layout:1.1.3&#39;
        testImplementation &#39;junit:junit:4.12&#39;
        androidTestImplementation &#39;com.android.support.test:runner:1.0.2&#39;
        implementation &#39;com.github.bassaer:chatmessageview:2.0.1&#39;
        implementation &#39;com.google.code.gson:gson:2.8.5&#39;
        androidTestImplementation &#39;com.android.support.test.espresso:espresso-core:3.0.2&#39;
    }

Duplicate class android.support.v4.app.INotificationSideChannel found in modules classes?

I came to know about [ViewPager2][1] and tried to implement it, but didn&#39;t find any proper example.

Can anyone tell me how can I use it.

I am looking for proper usage, not an example.


  [1]: https://developer.android.com/jetpack/androidx/releases/viewpager2#1.0.0-alpha01

Proper implementation of ViewPager2 in Android

Is it possible to enable-disable swiping in new android [`viewpager2`][1] component?


  [1]: https://developer.android.com/jetpack/androidx/releases/viewpager2

How to disable swiping in ViewPager2?

I upgraded my `android studio to 3.4 canary` and now I cannot successfully build anymore due to the following error: 

    The given artifact contains a string literal with a package reference &#39;android.support.v4.content&#39; that cannot be safely rewritten. Libraries using reflection such as annotation processors need to be updated manually to add support for androidx.

More details:

    Caused by: java.lang.RuntimeException: Failed to transform &#39;.gradle/caches/modules-2/files-2.1/com.jakewharton/butterknife-compiler/9.0.0-SNAPSHOT/732f93940c74cf32a7c5ddcc5ef66e53be052352/butterknife-compiler-9.0.0-SNAPSHOT.jar&#39; using Jetifier. Reason: The given artifact contains a string literal with a package reference &#39;android.support.v4.content&#39; that cannot be safely rewritten. Libraries using reflection such as annotation processors need to be updated manually to add support for androidx.. (Run with --stacktrace for more details.)
	

Clearly, its something to do with `Butterknife, androidx and Jetifier`

Do anybody know how to fix this?

The given artifact contains a string literal with a package reference &#39;android.support.v4.content&#39; that cannot be safely rewritten. for androidx

What is Jetifier? For example, to create a new project using the androidx-packaged dependencies, this new project needs to add the following line to the *gradle.properties* file:

    android.enableJetifier=true

So what does it mean - &quot;enable jetifier&quot;?

What is Jetifier?

In a newly created project with Androidx:appcompat:appcompat:1.0.0-rc01, I&#39;m getting the


    java.lang.ClassNotFoundException: Didn&#39;t find class 
    &quot;android.view.View$OnUnhandledKeyEventListener&quot; on path: DexPathList


I had also added configuration.all


    configurations.all {
        resolutionStrategy.eachDependency { DependencyResolveDetails details -&gt;
            def requested = details.requested
            if (requested.group == &quot;androidx.appcompat&quot;) {
                if (!requested.name.startsWith(&quot;multidex&quot;)) {
                    details.useVersion &quot;1.+&quot;
                }
            }
        }
    }

This one is not affecting the app functionality or crashes. But it always have this error when the app is running. Kindly help me to solve the error.
The entire stack trace is as follows.

    I/art: Rejecting re-init on previously-failed class java.lang.Class&lt;androidx.core.view.ViewCompat$OnUnhandledKeyEventListenerWrapper&gt;: java.lang.NoClassDefFoundError: Failed resolution of: Landroid/view/View$OnUnhandledKeyEventListener;
    I/art:     at void androidx.core.view.ViewCompat.setBackground(android.view.View, android.graphics.drawable.Drawable) (ViewCompat.java:2341)
            at void androidx.appcompat.widget.ActionBarContainer.&lt;init&gt;(android.content.Context, android.util.AttributeSet) (ActionBarContainer.java:62)
            at java.lang.Object java.lang.reflect.Constructor.newInstance0!(java.lang.Object[]) (Constructor.java:-2)
            at java.lang.Object java.lang.reflect.Constructor.newInstance(java.lang.Object[]) (Constructor.java:430)
            at android.view.View android.view.LayoutInflater.createView(java.lang.String, java.lang.String, android.util.AttributeSet) (LayoutInflater.java:645)
            at android.view.View android.view.LayoutInflater.createViewFromTag(android.view.View, java.lang.String, android.content.Context, android.util.AttributeSet, boolean) (LayoutInflater.java:787)
            at android.view.View android.view.LayoutInflater.createViewFromTag(android.view.View, java.lang.String, android.content.Context, android.util.AttributeSet) (LayoutInflater.java:727)
            at void android.view.LayoutInflater.rInflate(org.xmlpull.v1.XmlPullParser, android.view.View, android.content.Context, android.util.AttributeSet, boolean) (LayoutInflater.java:858)
            at void android.view.LayoutInflater.rInflateChildren(org.xmlpull.v1.XmlPullParser, android.view.View, android.util.AttributeSet, boolean) (LayoutInflater.java:821)
            at android.view.View android.view.LayoutInflater.inflate(org.xmlpull.v1.XmlPullParser, android.view.ViewGroup, boolean) (LayoutInflater.java:518)
            at android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup, boolean) (LayoutInflater.java:426)
            at android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup) (LayoutInflater.java:377)
            at android.view.ViewGroup androidx.appcompat.app.AppCompatDelegateImpl.createSubDecor() (AppCompatDelegateImpl.java:607)
            at void androidx.appcompat.app.AppCompatDelegateImpl.ensureSubDecor() (AppCompatDelegateImpl.java:518)
            at void androidx.appcompat.app.AppCompatDelegateImpl.setContentView(int) (AppCompatDelegateImpl.java:466)
            at void androidx.appcompat.app.AppCompatActivity.setContentView(int) (AppCompatActivity.java:140)
            at void com.connectdb.truckish.common.base.BaseActivity.onCreate(android.os.Bundle) (BaseActivity.java:44)
            at void com.connectdb.truckish.MainActivity.onCreate(android.os.Bundle) (MainActivity.java:14)
            at void android.app.Activity.performCreate(android.os.Bundle) (Activity.java:6672)
            at void android.app.Instrumentation.callActivityOnCreate(android.app.Activity, android.os.Bundle) (Instrumentation.java:1140)
            at android.app.Activity android.app.ActivityThread.performLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent) (ActivityThread.java:2612)
            at void android.app.ActivityThread.handleLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:2724)
            at void android.app.ActivityThread.-wrap12(android.app.ActivityThread, android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:-1)
            at void android.app.ActivityThread$H.handleMessage(android.os.Message) (ActivityThread.java:1473)
            at void android.os.Handler.dispatchMessage(android.os.Message) (Handler.java:102)
            at void android.os.Looper.loop() (Looper.java:154)
            at void android.app.ActivityThread.main(java.lang.String[]) (ActivityThread.java:6123)
            at java.lang.Object java.lang.reflect.Method.invoke!(java.lang.Object, java.lang.Object[]) (Method.java:-2)
            at void com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run() (ZygoteInit.java:867)
            at void com.android.internal.os.ZygoteInit.main(java.lang.String[]) (ZygoteInit.java:757)
        Caused by: java.lang.ClassNotFoundException: Didn&#39;t find class &quot;android.view.View$OnUnhandledKeyEventListener&quot; on path: DexPathList[[zip file &quot;/data/app/com.connectdb.truckish-2/base.apk&quot;, zip file &quot;/data/app/com.connectdb.truckish-2/split_lib_dependencies_apk.apk&quot;, zip file &quot;/data/app/com.connectdb.truckish-2/split_lib_slice_0_apk.apk&quot;, zip file &quot;/data/app/com.connectdb.truckish-2/split_lib_slice_1_apk.apk&quot;, zip file &quot;/data/app/com.connectdb.truckish-2/split_lib_slice_2_apk.apk&quot;, zip file &quot;/data/app/com.connectdb.truckish-2/split_lib_slice_3_apk.apk&quot;, zip file &quot;/data/app/com.connectdb.truckish-2/split_lib_slice_4_apk.apk&quot;, zip file &quot;/data/app/com.connectdb.truckish-2/split_lib_slice_5_apk.apk&quot;, zip file &quot;/data/app/com.connectdb.truckish-2/split_lib_slice_6_apk.apk&quot;, zip file &quot;/data/app/com.connectdb.truckish-2/split_lib_slice_7_apk.apk&quot;, zip file &quot;/data/app/com.connectdb.truckish-2/split_lib_slice_8_apk.apk&quot;, zip file &quot;/data/app/com.connectdb.truckish-2/split_lib_slice_9_apk.apk&quot;],nativeLibraryDirectories=[
            at java.lang.Class dalvik.system.BaseDexClassLoader.findClass(java.lang.String) (BaseDexClassLoader.java:56)
            at java.lang.Class java.lang.ClassLoader.loadClass(java.lang.String, boolean) (ClassLoader.java:380)
            at java.lang.Class java.lang.ClassLoader.loadClass(java.lang.String) (ClassLoader.java:312)
            at void androidx.core.view.ViewCompat.setBackground(android.view.View, android.graphics.drawable.Drawable) (ViewCompat.java:2341)
            at void androidx.appcompat.widget.ActionBarContainer.&lt;init&gt;(android.content.Context, android.util.AttributeSet) (ActionBarContainer.java:62)
            at java.lang.Object java.lang.reflect.Constructor.newInstance0!(java.lang.Object[]) (Constructor.java:-2)
            at java.lang.Object java.lang.reflect.Constructor.newInstance(java.lang.Object[]) (Constructor.java:430)
            at android.view.View android.view.LayoutInflater.createView(java.lang.String, java.lang.String, android.util.AttributeSet) (LayoutInflater.java:645)
            at android.view.View android.view.LayoutInflater.createViewFromTag(android.view.View, java.lang.String, android.content.Context, android.util.AttributeSet, boolean) (LayoutInflater.java:787)
            at android.view.View android.view.LayoutInflater.createViewFromTag(android.view.View, java.lang.String, android.content.Context, android.util.AttributeSet) (LayoutInflater.java:727)
            at void android.view.LayoutInflater.rInflate(org.xmlpull.v1.XmlPullParser, android.view.View, android.content.Context, android.util.AttributeSet, boolean) (LayoutInflater.java:858)
            at void android.view.LayoutInflater.rInflateChildren(org.xmlpull.v1.XmlPullParser, android.view.View, android.util.AttributeSet, boolean) (LayoutInflater.java:821)
            at android.view.View android.view.LayoutInflater.inflate(org.xmlpull.v1.XmlPullParser, android.view.ViewGroup, boolean) (LayoutInflater.java:518)
            at android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup, boolean) (LayoutInflater.java:426)
            at android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup) (LayoutInflater.java:377)
            at android.view.ViewGroup androidx.appcompat.app.AppCompatDelegateImpl.createSubDecor() (AppCompatDelegateImpl.java:607)
            at void androidx.appcompat.app.AppCompatDelegateImpl.ensureSubDecor() (AppCompatDelegateImpl.java:518)
            at void androidx.appcompat.app.AppCompatDelegateImpl.setContentView(int) (AppCompatDelegateImpl.java:466)
            at void androidx.appcompat.app.AppCompatActivity.setContentView(int) (AppCompatActivity.java:140)
            at void com.connectdb.truckish.common.base.BaseActivity.onCreate(android.os.Bundle) (BaseActivity.java:44)
            at void com.connectdb.truckish.MainActivity.onCreate(android.os.Bundle) (MainActivity.java:14)
            at void android.app.Activity.performCreate(android.os.Bundle) (Activity.java:6672)
            at void android.app.Instrumentation.callActivityOnCreate(android.app.Activity, android.os.Bundle) (Instrumentation.java:1140)
            at android.app.Activity android.app.ActivityThread.performLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent) (ActivityThread.java:2612)
            at void android.app.ActivityThread.handleLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:2724)
            at void android.app.ActivityThread.-wrap12(android.app.ActivityThread, android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:-1)
            at void android.app.ActivityThread$H.handleMessage(android.os.Message) (ActivityThread.java:1473)
            at void android.os.Handler.dispatchMessage(android.os.Message) (Handler.java:102)
            at void android.os.Looper.loop() (Looper.java:154)
            at void android.app.ActivityThread.main(java.lang.String[]) (ActivityThread.java:6123)
            at java.lang.Object java.lang.reflect.Method.invoke!(java.lang.Object, java.lang.Object[]) (Method.java:-2)
            at void com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run() (ZygoteInit.java:867)
            at void com.android.internal.os.ZygoteInit.main(java.lang.String[]) (ZygoteInit.java:757)



AndroidX:Appcompat I:art error android.view.View$OnUnhandledKeyEventListener

I am working with Single viewModel for the Activity and all of it&#39;s fragment.

So to initialise `viewmodel` if have to write this setup code in `onActivityCreated` of all the fragment&#39;s

        override fun onActivityCreated(savedInstanceState: Bundle?) {
            super.onActivityCreated(savedInstanceState)
            viewModel = ViewModelProviders.of(activity!!).get(NoteViewModel::class.java)
        }

I was going thorough the Android KTX extension page:([refer here][1]) 

and i found i can initialise view model like this:

        // Get a reference to the ViewModel scoped to this Fragment
        val viewModel by viewModels&lt;MyViewModel&gt;()
    
        // Get a reference to the ViewModel scoped to its Activity
        val viewModel by activityViewModels&lt;MyViewModel&gt;()

So I added below dependency&#39;s to my gradle(app):

        //ktx android
        implementation &#39;androidx.core:core-ktx:1.0.2&#39;
        implementation &#39;androidx.fragment:fragment-ktx:1.0.0&#39;
        implementation &quot;androidx.lifecycle:lifecycle-extensions:2.0.0&quot;

But when i try to use `viewModels/activityViewModels` in my application their reference in not found.
  
I want help in how to use these extension&#39;s with some basic example i tried searching for examples haven&#39;t found any.

  [1]: https://developer.android.com/kotlin/ktx#fragment

how to get viewModel by viewModels? (fragment-ktx)

I was using the `BottomSheetBehavior` with the original support library:

    implementation &#39;com.android.support:design:27.1.1&#39; 

When I migrated to use the new `androidx` libraries though the `BottomSheetBehavior` is missing. The mapping from the above support library isn&#39;t in the [AndroidX Refactoring List][1] either, but the migration tool removed it.

What am I missing to include the BottomSheetBehavior with the new `androidx` libraries.

    dependencies {
        implementation fileTree(dir: &#39;libs&#39;, include: [&#39;*.jar&#39;])
        implementation &#39;com.google.android.material:material:1.0.0-beta01&#39;
        implementation &quot;org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version&quot;
    
        // ReactiveX
        implementation &#39;io.reactivex.rxjava2:rxandroid:2.0.2&#39;
        implementation &#39;io.reactivex.rxjava2:rxkotlin:2.2.0&#39;
    
        implementation &#39;com.android.support:design:28.1.0&#39;
    
        // Android Compatability Libraries
        // Version: https://developer.android.com/topic/libraries/support-library/refactor
        implementation &#39;androidx.appcompat:appcompat:1.0.0-beta01&#39;
        implementation &#39;androidx.constraintlayout:constraintlayout:2.0.0-alpha1&#39;
        implementation &#39;androidx.legacy:legacy-support-v4:1.0.0-beta01&#39;
        implementation &#39;androidx.lifecycle:lifecycle-extensions:2.0.0-beta01&#39;
        implementation &#39;androidx.recyclerview:recyclerview:1.0.0-beta01&#39;
    
        // Android Navigation Component
        // Check here for updated version info - will move to androidx soon.
        // https://developer.android.com/topic/libraries/architecture/adding-components
        def nav_version = &quot;1.0.0-alpha04&quot;
    
        // use -ktx for Kotlin
        implementation &quot;android.arch.navigation:navigation-fragment-ktx:$nav_version&quot;
        implementation &quot;android.arch.navigation:navigation-ui-ktx:$nav_version&quot;
        androidTestImplementation &quot;android.arch.navigation:navigation-testing-ktx:$nav_version&quot;
    
        // Testing
        testImplementation &#39;junit:junit:4.12&#39;
        androidTestImplementation &#39;androidx.test:runner:1.1.0-alpha4&#39;
        androidTestImplementation &#39;androidx.test.espresso:espresso-core:3.1.0-alpha4&#39;
    }


  [1]: https://developer.android.com/topic/libraries/support-library/refactor


BottomSheetBehavior not in androidX libraries

I am trying to get the `TextView` of the `Snackbar` with this code snippet:

    snackbarView.findViewById&lt;TextView&gt;(android.support.design.R.id.snackbar_text)  

but Android Studio does not resolve the design library. 

How can I get this code to work?

Can&#39;t resolve android.support.design. after migration to AndroidX

My application works fine from Android 4.3 until Android 9 Pie, but my application doesn&#39;t work on Android 10 (Q API 29) and crashes. This is my logcat - why this is happening?

    java.lang.RuntimeException: Unable to start activity 
         ComponentInfo{ir.mahdi.circulars/ir.mahdi.circulars.MainActivity}: 
         android.view.InflateException: Binary XML file line #17 
         in ir.mahdi.circulars:layout/abc_screen_simple: Binary XML file line #17 
         in ir.mahdi.circulars:layout/abc_screen_simple: 
             Error inflating class androidx.appcompat.widget.FitWindowsLinearLayout

and this is my mainActivity.xml

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
        xmlns:app=&quot;http://schemas.android.com/apk/res-auto&quot;
        xmlns:tools=&quot;http://schemas.android.com/tools&quot;
        android:layout_width=&quot;match_parent&quot;
        android:layout_height=&quot;match_parent&quot;
        android:background=&quot;@color/white&quot;
        android:layoutDirection=&quot;ltr&quot;
        tools:context=&quot;.MainActivity&quot;&gt;
        
      
    &lt;/androidx.coordinatorlayout.widget.CoordinatorLayout&gt;

update

    apply plugin: &#39;com.android.application&#39;
    
    android {
        compileSdkVersion 29
        defaultConfig {
            minSdkVersion 16
            targetSdkVersion 29
            multiDexEnabled true
            testInstrumentationRunner &quot;androidx.test.runner.AndroidJUnitRunner&quot;
        }
        buildTypes {
            release {
                minifyEnabled false
                proguardFiles getDefaultProguardFile(&#39;proguard-android-optimize.txt&#39;), &#39;proguard-rules.pro&#39;
            }
        } }
    
    dependencies {
        implementation fileTree(dir: &#39;libs&#39;, include: [&#39;*.jar&#39;])
        implementation &#39;androidx.appcompat:appcompat:1.0.0&#39;
        implementation &#39;com.google.android.material:material:1.0.0&#39;
        implementation &#39;androidx.constraintlayout:constraintlayout:1.1.3&#39;
        testImplementation &#39;junit:junit:4.12&#39;
        androidTestImplementation &#39;androidx.test:runner:1.2.0&#39;
        androidTestImplementation &#39;androidx.test.espresso:espresso-core:3.2.0&#39; }



Crash on Android 10 (InflateException in layout/abc_screen_simple line #17)

I just made a migration to androidx through Android Studio menu option **Refactor** -&gt; **Refactor to AndroidX**

I&#39;m getting the following error:  


&gt; android.view.InflateException: Binary XML file line #2: Binary XML file line #2: Error inflating class androidx.constraintlayout.ConstraintLayout
    
    
    
Any idea?
    
Stacktrace:
    
    2018-10-19 00:25:58.128 28131-28131/com.midounoo.midounoo E/AndroidRuntime: FATAL EXCEPTION: main
        Process: com.midounoo.midounoo, PID: 28131
        java.lang.RuntimeException: Unable to start activity ComponentInfo{com.midounoo.midounoo/com.midounoo.midounoo.Base.MainActivity}: android.view.InflateException: Binary XML file line #2: Binary XML file line #2: Error inflating class androidx.constraintlayout.ConstraintLayout
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2724)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2789)
            at android.app.ActivityThread.-wrap12(ActivityThread.java)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1527)
            at android.os.Handler.dispatchMessage(Handler.java:110)
            at android.os.Looper.loop(Looper.java:203)
            at android.app.ActivityThread.main(ActivityThread.java:6255)
            at java.lang.reflect.Method.invoke(Native Method)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1063)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:924)
         Caused by: android.view.InflateException: Binary XML file line #2: Binary XML file line #2: Error inflating class androidx.constraintlayout.ConstraintLayout
         Caused by: android.view.InflateException: Binary XML file line #2: Error inflating class androidx.constraintlayout.ConstraintLayout
         Caused by: java.lang.ClassNotFoundException: Didn&#39;t find class &quot;androidx.constraintlayout.ConstraintLayout&quot; on path: DexPathList[[zip file &quot;/data/app/com.midounoo.midounoo-2/base.apk&quot;, zip file &quot;/data/app/com.midounoo.midounoo-2/split_lib_dependencies_apk.apk&quot;, zip file &quot;/data/app/com.midounoo.midounoo-2/split_lib_slice_0_apk.apk&quot;, zip file &quot;/data/app/com.midounoo.midounoo-2/split_lib_slice_1_apk.apk&quot;, zip file &quot;/data/app/com.midounoo.midounoo-2/split_lib_slice_2_apk.apk&quot;, zip file &quot;/data/app/com.midounoo.midounoo-2/split_lib_slice_3_apk.apk&quot;, zip file &quot;/data/app/com.midounoo.midounoo-2/split_lib_slice_4_apk.apk&quot;, zip file &quot;/data/app/com.midounoo.midounoo-2/split_lib_slice_5_apk.apk&quot;, zip file &quot;/data/app/com.midounoo.midounoo-2/split_lib_slice_6_apk.apk&quot;, zip file &quot;/data/app/com.midounoo.midounoo-2/split_lib_slice_7_apk.apk&quot;, zip file &quot;/data/app/com.midounoo.midounoo-2/split_lib_slice_8_apk.apk&quot;, zip file &quot;/data/app/com.midounoo.midounoo-2/split_lib_slice_9_apk.apk&quot;],nativeLibraryDirectories=[/data/app/com.midounoo.midounoo-2/lib/arm64, /system/lib64, /vendor/lib64, /system/vendor/lib64]]
            at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
            at java.lang.ClassLoader.loadClass(ClassLoader.java:380)
            at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
            at android.view.LayoutInflater.createView(LayoutInflater.java:609)
            at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:787)
            at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:727)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:495)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:426)
            at android.view.LayoutInflater.inflate(LayoutInflater.java:377)
            at androidx.appcompat.app.AppCompatDelegateImpl.setContentView(AppCompatDelegateImpl.java:469)
            at androidx.appcompat.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
            at com.midounoo.midounoo.Base.MainActivity.onCreate(MainActivity.java:43)
            at android.app.Activity.performCreate(Activity.java:6666)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2677)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2789)
            at android.app.ActivityThread.-wrap12(ActivityThread.java)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1527)
            at android.os.Handler.dispatchMessage(Handler.java:110)
            at android.os.Looper.loop(Looper.java:203)
            at android.app.ActivityThread.main(ActivityThread.java:6255)
            at java.lang.reflect.Method.invoke(Native Method)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1063)

Error inflating class androidx.constraintlayout.ConstraintLayout after migration to androidx

I&#39;m migrating my `ViewPager` to `ViewPager2` since the latter is supposed to solve all the problems of the former. Unfortunately, when using it with a `FragmentStateAdapter`, I don&#39;t find any way to get the currently displayed fragment.

`viewPager.getCurrentItem()` gives the current displayed index and `adapter.getItem(index)` generally creates a new `Fragment` for the current index. Unless keeping a reference to all created fragments in `getItem()`, I have no idea how to access the currently displayed fragment.

With the old `ViewPager`, one solution was to call `adapter.instantiateItem(index)` which would return the fragment at the desired index.

Am I missing something with `ViewPager2`?

Get current fragment with ViewPager2

I&#39;m creating an Android app and I&#39;m using the AndroidX libraries and Material design theme. My app theme on `styles.xml` is:

    &lt;style name=&quot;AppTheme&quot; parent=&quot;Theme.MaterialComponents.Light.DarkActionBar&quot;&gt;
        &lt;item name=&quot;colorPrimary&quot;&gt;@color/colorPrimary&lt;/item&gt;
        &lt;item name=&quot;colorPrimaryDark&quot;&gt;@color/colorPrimaryDark&lt;/item&gt;
        &lt;item name=&quot;colorAccent&quot;&gt;@color/colorAccent&lt;/item&gt;
    &lt;/style&gt;

I have the following FAB from a custom library:

    &lt;com.leinardi.android.speeddial.SpeedDialView
            android:id=&quot;@+id/work_log_fab&quot;
            android:layout_width=&quot;wrap_content&quot;
            android:layout_height=&quot;wrap_content&quot;
            android:layout_gravity=&quot;bottom|end&quot;
            app:layout_behavior=&quot;@string/speeddial_scrolling_view_snackbar_behavior&quot;
            app:sdMainFabClosedSrc=&quot;@drawable/ic_add_white_24dp&quot;
            app:sdOverlayLayout=&quot;@id/overlay&quot; /&gt;

And also tried the default FAB:

    &lt;com.google.android.material.floatingactionbutton.FloatingActionButton
            android:id=&quot;@+id/fab&quot;
            android:layout_width=&quot;wrap_content&quot;
            android:layout_height=&quot;wrap_content&quot;
            android:layout_gravity=&quot;end|bottom&quot;
            android:src=&quot;@drawable/ic_add_white_24dp&quot;
            android:layout_margin=&quot;16dp&quot; /&gt;

No mater the color of the icon (a vector drawable), the icon inside the FAB (from the library and from the default) is always black. I have narrowed down the problem to the material design theme, since using the old `Theme.AppCompat.Light.DarkActionBar` instead of the new `Theme.MaterialComponents.Light.DarkActionBar` the icon inside the FAB gets the color of the original vector drawable.

Does anyone know why this is happening and how to solve it?

Android FAB icon always black with MaterialComponents theme

I want to use `com.google.android.material.tabs.TabLayout` component with Android&#39;s new `ViewPager` implementation `androidx.viewpager2.widget.ViewPager2`. However, the `setupWithViewPager(..)` method provided by `TabLayout` supports only the old `ViewPager` implementation. Is there a way to bind a `TabLayout` to a `ViewPager2` component easily?

How to use TabLayout with ViewPager2 in Android

I recently updated my Android Studio (and I&#39;m pretty sure the Gradle version), and now I&#39;ve been getting a bunch of errors when trying to compile my project. Here&#39;s the one that is plaguing me at the moment:

```
Duplicate class android.support.v4.app.INotificationSideChannel found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:26.1.0)
```

This is followed by lots of similar ones.

I tried removing all uses of ```com.android.support``` in favor of androidx (see [here][1] for what I was using the replace things), but ```com.android.support``` libraries are still being used, even when I delete the libraries (they&#39;re just remade once I try to compile again).

[Here&#39;s][2] a link to the full error I get.


  [1]: https://developer.android.com/jetpack/androidx/migrate
  [2]: https://pastebin.com/raw/W7xrRzU8

Duplicate classes from androidx and com.android.support

I&#39;m trying to move to migrate to androidx. I used the migration tool in Android Studio. When I do this I get the following stacktrace when I run my app.

    E/AndroidRuntime: FATAL EXCEPTION: main
        Process: com.peerke.outdoorpuzzlegame.debug, PID: 10901
        java.lang.RuntimeException: Unable to get provider android.support.v4.content.FileProvider: java.lang.ClassNotFoundException: Didn&#39;t find class &quot;android.support.v4.content.FileProvider&quot; on path: DexPathList[[zip file &quot;/data/app/com.peerke.outdoorpuzzlegame.debug-IBtFsngoLqc-cQb_hOO5wQ==/base.apk&quot;],nativeLibraryDirectories=[/data/app/com.peerke.outdoorpuzzlegame.debug-IBtFsngoLqc-cQb_hOO5wQ==/lib/x86, /system/lib]]
            at android.app.ActivityThread.installProvider(ActivityThread.java:6376)
            at android.app.ActivityThread.installContentProviders(ActivityThread.java:5932)
            at android.app.ActivityThread.handleBindApplication(ActivityThread.java:5847)
            at android.app.ActivityThread.access$1000(ActivityThread.java:198)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1637)
            at android.os.Handler.dispatchMessage(Handler.java:106)
            at android.os.Looper.loop(Looper.java:164)
            at android.app.ActivityThread.main(ActivityThread.java:6649)
            at java.lang.reflect.Method.invoke(Native Method)
            at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:826)
         Caused by: java.lang.ClassNotFoundException: Didn&#39;t find class &quot;android.support.v4.content.FileProvider&quot; on path: DexPathList[[zip file &quot;/data/app/com.peerke.outdoorpuzzlegame.debug-IBtFsngoLqc-cQb_hOO5wQ==/base.apk&quot;],nativeLibraryDirectories=[/data/app/com.peerke.outdoorpuzzlegame.debug-IBtFsngoLqc-cQb_hOO5wQ==/lib/x86, /system/lib]]
            at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:125)
            at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
            at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
            at android.app.AppComponentFactory.instantiateProvider(AppComponentFactory.java:121)
            at androidx.core.app.CoreComponentFactory.instantiateProvider(CoreComponentFactory.java:62)
            at android.app.ActivityThread.installProvider(ActivityThread.java:6360)
            at android.app.ActivityThread.installContentProviders(ActivityThread.java:5932)&#160;
            at android.app.ActivityThread.handleBindApplication(ActivityThread.java:5847)&#160;
            at android.app.ActivityThread.access$1000(ActivityThread.java:198)&#160;
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1637)&#160;
            at android.os.Handler.dispatchMessage(Handler.java:106)&#160;
            at android.os.Looper.loop(Looper.java:164)&#160;
            at android.app.ActivityThread.main(ActivityThread.java:6649)&#160;
            at java.lang.reflect.Method.invoke(Native Method)&#160;
            at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)&#160;
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:826)&#160;

The exception is correct. android.support.v4.content.FileProvider doesn&#39;t exist in my app. But androidx.core.content.FileProvider is included in my app. 
The big question is why does it want to load the old version of FileProvider? 

ClassNotFoundException: Didn&#39;t find class &quot;android.support.v4.content.FileProvider&quot; after androidx migration

I have tried many solutions on this website but still, the problem is not solved. The issue is due to Android X library. When I added Android X, this issue was resolved but it opened up new issue. How to fix this issue?

Earlier this error was coming:

    Manifest merger failed : Attribute application@appComponentFactory value=(android.support.v4.app.CoreComponentFactory) from [com.android.support:support-compat:28.0.0] AndroidManifest.xml:22:18-91
	is also present at [androidx.core:core:1.0.0] AndroidManifest.xml:22:18-86 value=(androidx.core.app.CoreComponentFactory).
	Suggestion: add &#39;tools:replace=&quot;android:appComponentFactory&quot;&#39; to &lt;application&gt; element at AndroidManifest.xml:19:5-142:19 to override.

After I added `tools:replace=&quot;android:appComponentFactory&quot;`, this error is came:

     java.lang.RuntimeException: Manifest merger failed with multiple errors, see logs
    at com.android.builder.core.AndroidBuilder.mergeManifestsForApplication(AndroidBuilder.java:540) 	
    at com.android.build.gradle.tasks.MergeManifests.doFullTaskAction(MergeManifests.java:173)

Merging Error (in Android Manifest):

&gt; Error: tools:replace specified at line:2 for attribute
&gt; android:appComponentFactory, but no new value specified app main
&gt; manifest (this file), line 1

Manifest:

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;manifest
        package=&quot;com.example&quot;
        xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
        xmlns:tools=&quot;http://schemas.android.com/tools&quot;
        tools:replace=&quot;allowBackup, android:appComponentFactory&quot;
        android:allowBackup=&quot;false&quot;&gt;
    
        ...

        &lt;application
            android:name=&quot;com.example&quot;
            android:icon=&quot;@mipmap/icon&quot;
            android:debuggable=&quot;true&quot;
            android:hardwareAccelerated=&quot;false&quot;
            android:largeHeap=&quot;true&quot;
            android:supportsRtl=&quot;true&quot;
            android:theme=&quot;@style/AppTheme&quot;
            android:allowBackup=&quot;false&quot;
            tools:ignore=&quot;GoogleAppIndexingWarning,HardcodedDebugMode&quot;&gt;
           ...


Android X: tools:replace specified at line: for attribute, but no new value specified

Following is the code I&#39;m using. I&#39;m using androidx. Every FAB has a black icon, even if it has a white color.

mylayout.xml

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
        xmlns:app=&quot;http://schemas.android.com/apk/res-auto&quot;
        xmlns:tools=&quot;http://schemas.android.com/tools&quot;
        android:layout_width=&quot;match_parent&quot;
        android:layout_height=&quot;match_parent&quot;
        android:layout_gravity=&quot;center&quot;
        app:layout_behavior=&quot;@string/appbar_scrolling_view_behavior&quot;&gt;

        &lt;include layout=&quot;@layout/content_geral&quot; /&gt;

        &lt;com.google.android.material.floatingactionbutton.FloatingActionButton
            android:id=&quot;@+id/fab&quot;
            android:layout_width=&quot;wrap_content&quot;
            android:layout_height=&quot;wrap_content&quot;
            android:layout_gravity=&quot;bottom|end&quot;
            android:layout_margin=&quot;24dp&quot;
            app:backgroundTint=&quot;@color/colorPrimary&quot;
            app:srcCompat=&quot;@drawable/ic_cloud_upload&quot;
            tools:ignore=&quot;VectorDrawableCompat&quot; /&gt;

    &lt;/androidx.coordinatorlayout.widget.CoordinatorLayout&gt;

style.xml

     &lt;!-- Base application theme. --&gt;
        &lt;style name=&quot;AppTheme&quot; parent=&quot;Theme.MaterialComponents.Light.DarkActionBar&quot;&gt;
            &lt;!-- Customize your theme here. --&gt;
            &lt;item name=&quot;colorPrimary&quot;&gt;@color/colorPrimary&lt;/item&gt;
            &lt;item name=&quot;colorPrimaryDark&quot;&gt;@color/colorPrimaryDark&lt;/item&gt;
            &lt;item name=&quot;colorAccent&quot;&gt;@color/colorAccent&lt;/item&gt;
            &lt;item name=&quot;windowNoTitle&quot;&gt;true&lt;/item&gt;
            &lt;item name=&quot;windowActionBar&quot;&gt;false&lt;/item&gt;
        &lt;/style&gt;

[![enter image description here][1]][1]

  [1]: https://i.stack.imgur.com/ecKhg.png


Why is my FloatingActionButton icon black?

I have an old project that supports multi-languages. I want to upgrade support library and target platform, **Before migrating to `Androidx` everything works fine but now change language not work!**

I use this code to change default locale of App

    private static Context updateResources(Context context, String language)
    {
    	Locale locale = new Locale(language);
    	Locale.setDefault(locale);
    
    	Configuration configuration = context.getResources().getConfiguration();
    	configuration.setLocale(locale);
    
    	return context.createConfigurationContext(configuration);
    }

And call this method on each activity by override `attachBaseContext` like this:

    @Override
    protected void attachBaseContext(Context newBase)
    {
        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
		String language = preferences.getString(SELECTED_LANGUAGE, &quot;fa&quot;);
    	super.attachBaseContext(updateResources(newBase, language));
    }

I try other method to get string and I noticed that ‍‍‍‍`getActivity().getBaseContext().getString` work and `getActivity().getString` not work. Even the following code does not work and always show `app_name` vlaue in default resource string.xml. 

	&lt;TextView
		android:id=&quot;@+id/textView&quot;
		android:layout_width=&quot;wrap_content&quot;
		android:layout_height=&quot;wrap_content&quot;
		android:text=&quot;@string/app_name&quot;/&gt;

I share a sample code in [https://github.com/Freydoonk/LanguageTest][1]

Also `getActivity()..getResources().getIdentifier` not work and always return 0!


  [1]: https://github.com/Freydoonk/LanguageTest

Change Locale not work after migrate to Androidx

How to add cardview in layout xml in AndroidX

After upgraded to AndroidX

    &lt;android.support.v7.widget.CardView xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
        xmlns:tools=&quot;http://schemas.android.com/tools&quot;
        android:layout_width=&quot;match_parent&quot;
        android:layout_height=&quot;wrap_content&quot;
        android:layout_margin=&quot;5dp&quot;&gt;

gives a error

&gt; The following classes could not be found:
&gt; -&#160;android.support.v7.widget.CardView (Fix Build Path, Edit XML, Create Class)

    dependencies {
    
        implementation &#39;androidx.appcompat:appcompat:1.0.0&#39;
        
        implementation &#39;androidx.cardview:cardview:1.0.0&#39;

but I don&#39;t know how to use CardView in xml under AndroidX

Thank you

How to add cardview in layout xml in AndroidX

When I&#39;m building Gradle with `androidx` I get the following error. Please help me to solve this issue.

&gt; Error Message: Manifest merger failed : Attribute
&gt; application@appComponentFactory
&gt; value=(android.support.v4.app.CoreComponentFactory) from
&gt; [com.android.support:support-compat:28.0.0]
&gt; AndroidManifest.xml:22:18-91 	is also present at
&gt; [androidx.core:core:1.0.0] AndroidManifest.xml:22:18-86
&gt; value=(androidx.core.app.CoreComponentFactory).



Manifest:

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;manifest xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
        xmlns:tools=&quot;http://schemas.android.com/tools&quot;
        package=&quot;com.kanwarpreet.dealmybook&quot;&gt;
    
        &lt;application
            android:allowBackup=&quot;true&quot;
            android:icon=&quot;@mipmap/ic_launcher&quot;
            android:label=&quot;@string/app_name&quot;
            android:roundIcon=&quot;@mipmap/ic_launcher_round&quot;
            android:supportsRtl=&quot;true&quot;
            android:theme=&quot;@style/AppTheme&quot;&gt;
    
            &lt;activity android:name=&quot;.activities.SplashActivity&quot; &gt;
                &lt;intent-filter&gt;
                    &lt;action android:name=&quot;android.intent.action.MAIN&quot; /&gt;
                    &lt;category android:name=&quot;android.intent.category.LAUNCHER&quot; /&gt;
                &lt;/intent-filter&gt;
            &lt;/activity&gt;
            &lt;activity android:name=&quot;.activities.LoginActivity&quot; /&gt;
            &lt;activity android:name=&quot;.activities.RegisterActivity&quot; /&gt;
            &lt;activity
                android:name=&quot;.activities.HomeActivity&quot;
                android:label=&quot;@string/title_activity_home&quot;
                android:theme=&quot;@style/AppTheme.NoActionBar&quot; /&gt;
            &lt;activity
                android:name=&quot;.activities.BookDetailsActivity&quot;
                android:label=&quot;@string/title_activity_book_details&quot;
                android:theme=&quot;@style/AppTheme.NoActionBar&quot;/&gt;
            &lt;activity android:name=&quot;.activities.AddBookActivity&quot; /&gt;
        &lt;/application&gt;
    
    &lt;/manifest&gt;

Build.Gradle:

    apply plugin: &#39;com.android.application&#39;
    
    android {
        compileSdkVersion 28
        defaultConfig {
            applicationId &quot;com.kanwarpreet.dealmybook&quot;
            minSdkVersion 21
            targetSdkVersion 28
            versionCode 1
            versionName &quot;1.0&quot;
            testInstrumentationRunner &quot;android.support.test.runner.AndroidJUnitRunner&quot;
        }
        buildTypes {
            release {
                minifyEnabled false
                proguardFiles getDefaultProguardFile(&#39;proguard-android-optimize.txt&#39;), &#39;proguard-rules.pro&#39;
            }
        }
    }
    
    dependencies {
        implementation fileTree(dir: &#39;libs&#39;, include: [&#39;*.jar&#39;])
        implementation &#39;com.android.support:appcompat-v7:28.0.0&#39;
        implementation &#39;com.android.support.constraint:constraint-layout:1.1.3&#39;
        implementation &#39;com.android.support:support-v4:28.0.0&#39;
        implementation &#39;com.google.android.material:material:1.0.0&#39;
        implementation &#39;com.jakewharton:butterknife:10.1.0&#39;
        annotationProcessor &#39;com.jakewharton:butterknife-compiler:10.1.0&#39;
        testImplementation &#39;junit:junit:4.12&#39;
        androidTestImplementation &#39;com.android.support.test:runner:1.0.2&#39;
        androidTestImplementation &#39;com.android.support.test.espresso:espresso-core:3.0.2&#39;
    }



Manifest merger failed : Attribute application@appComponentFactory - Androidx

When I try to add Safe Args (Android Navigation) to my app&#39;s as following

 ( using this guide : https://developer.android.com/topic/libraries/architecture/navigation/navigation-pass-data ) :

    apply plugin: &#39;com.android.application&#39;
    apply plugin: &#39;androidx.navigation.safeargs&#39;
    
    apply plugin: &#39;kotlin-android&#39;
    
    apply plugin: &#39;kotlin-android-extensions&#39;
    apply plugin: &#39;com.google.gms.google-services&#39;
    
    android {...

I receive this error :



&gt; **Plugin with id &#39;androidx.navigation.safeargs&#39; not found.**




Plugin with id &#39;androidx.navigation.safeargs&#39; not found

Switched to `AndroidX` and received deprecated: `import androidx.test.InstrumentationRegistry`.

If I made next import: `import androidx.test.platform.app.InstrumentationRegistry
` I can&#39;t use `getContext()`.

Ex:
`val context = InstrumentationRegistry.getContext()`.

In `build.gradle`:

    androidTestImplementation &#39;androidx.test.ext:junit:1.0.0-beta02&#39;
    androidTestImplementation &#39;androidx.test:runner:1.1.0-beta02&#39;



androidx.test.InstrumentationRegistry is deprecated

I am migrating my app to androidx, I can&#39;t seem to get my unit tests working. I took example from [Google&#39;s AndroidJunitRunnerSample][1], which has been updated to use the new androidx api. I get the following error when trying to run my tests:

    java.lang.Exception: Delegate runner &#39;androidx.test.internal.runner.junit4.AndroidJUnit4ClassRunner&#39; for AndroidJUnit4 could not be loaded. Check your build configuration.

Here is my module build.gradle:

    android {
        defaultConfig {
            testInstrumentationRunner &quot;androidx.test.runner.AndroidJUnitRunner&quot;
        }
    }
    dependencies {
        // Test dependencies
        androidTestImplementation &#39;androidx.test:core:1.0.0-beta02&#39;
        androidTestImplementation &#39;androidx.test.ext:junit:1.0.0-beta02&#39;
        androidTestImplementation &#39;androidx.test:runner:1.1.0-beta02&#39;
        androidTestImplementation &#39;androidx.test.espresso:espresso-core:3.1.0-beta02&#39;
        androidTestImplementation &quot;androidx.arch.core:core-testing:2.0.0&quot;
        androidTestImplementation &#39;androidx.room:room-testing:2.1.0-alpha01&#39;
        androidTestImplementation &#39;androidx.test.espresso:espresso-core:3.1.0-beta02&#39;
        androidTestImplementation &#39;org.hamcrest:hamcrest-library:1.3&#39;
    }
And here is how my tests are structured:

    import org.junit.BeforeClass;
    import org.junit.Test;
    import org.junit.runner.RunWith;

    import androidx.test.ext.junit.runners.AndroidJUnit4;

    @RunWith(AndroidJUnit4.class)
    public class EntityParcelTest {
        
        @BeforeClass
        public void createEntities() {
            // Setup...
        }

        @Test
        void someTest() {
            // Testing here
        }

What am I doing wrong?


  [1]: https://github.com/googlesamples/android-testing/tree/master/runner/AndroidJunitRunnerSample/

Migrating Junit4 tests to androidx: What causes &#39;delegate runner could not be loaded&#39;?

For my instrumentation tests I was using 

    @RunWith(AndroidJUnit4.class)
from

    import androidx.test.runner.AndroidJUnit4;

in order to establish my test cases. Now this line gets marked as deprecated with the hint to use `AndroidJUnit4` from

    import androidx.test.ext.junit.runners.AndroidJUnit4

However if I try to import `AndroidJUnit4` from the named package I get the error, that `ext` can not be resolved.

Do you have an idea, what package should be included in gradle to resolve this issue?

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