How to implement the Android ActionBar back button?
JavaAndroidAndroid 3.0-HoneycombJava Problem Overview
I have an activity with a listview. When the user click the item, the item "viewer" opens:
List1.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,long arg3) {
Intent nextScreen = new Intent(context,ServicesViewActivity.class);
String[] Service = (String[])List1.getItemAtPosition(arg2);
//Sending data to another Activity
nextScreen.putExtra("data", datainfo);
startActivityForResult(nextScreen,0);
overridePendingTransition(R.anim.right_enter, R.anim.left_exit);
}
});
This works fine, but on the actionbar the back arrow next to the app icon doesn't get activated. Am I missing something?
Java Solutions
Solution 1 - Java
Selvin already posted the right answer. Here, the solution in pretty code:
public class ServicesViewActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// etc...
getActionBar().setDisplayHomeAsUpEnabled(true);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
NavUtils.navigateUpFromSameTask(this);
return true;
default:
return super.onOptionsItemSelected(item);
}
}
}
The function NavUtils.navigateUpFromSameTask(this)
requires you to define the parent activity in the AndroidManifest.xml file
<activity android:name="com.example.ServicesViewActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.ParentActivity" />
</activity>
See here for further reading.
Solution 2 - Java
Make sure your the ActionBar Home Button is enabled in the Activity:
##Android, API 5+:
@Override
public void onBackPressed() {
...
super.onBackPressed();
}
##ActionBarSherlock and App-Compat, API 7+:
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
...
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
##Android, API 11+:
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
...
getActionBar().setDisplayHomeAsUpEnabled(true);
}
Example MainActivity
that extends ActionBarActivity
:
public class MainActivity extends ActionBarActivity {
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Back button
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
// API 5+ solution
onBackPressed();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
}
This way all the activities you want can have the backpress.
##Android, API 16+:
http://developer.android.com/training/implementing-navigation/ancestral.html
AndroidManifest.xml
:
<application ... >
...
<!-- The main/home activity (it has no parent activity) -->
<activity
android:name="com.example.myfirstapp.MainActivity" ...>
...
</activity>
<!-- A child of the main activity -->
<activity
android:name="com.example.myfirstapp.DisplayMessageActivity"
android:label="@string/title_activity_display_message"
android:parentActivityName="com.example.myfirstapp.MainActivity" >
<!-- The meta-data element is needed for versions lower than 4.1 -->
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.myfirstapp.MainActivity" />
</activity>
</application>
Example MainActivity
that extends ActionBarActivity
:
public class MainActivity extends ActionBarActivity {
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Back button
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
// Respond to the action bar's Up/Home button
case android.R.id.home:
NavUtils.navigateUpFromSameTask(this);
return true;
}
return super.onOptionsItemSelected(item);
}
}
Solution 3 - Java
To enable the ActionBar back button you obviously need an ActionBar in your Activity.
This is set by the theme you are using. You can set the theme for your Activity in the AndroidManfiest.xml
. If you are using e.g the @android:style/Theme.NoTitleBar
theme, you don't have an ActionBar. In this case the call to getActionBar()
will return null. So make sure you have an ActionBar first.
The next step is to set the android:parentActivityName
to the activity you want to navigate if you press the back button. This should be done in the AndroidManifest.xml
too.
Now you can enable the back button in the onCreate
method of your "child" activity.
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getActionBar().setDisplayHomeAsUpEnabled(true);
}
Now you should implement the logic for the back button. You simply override the onOptionsItemSelected
method in your "child" activity and check for the id of the back button which is android.R.id.home
.
Now you can fire the method NavUtils.navigateUpFromSameTask(this);
BUT if you don't have specified the android:parentActivityName
in you AndroidManifest.xml
this will crash your app.
Sometimes this is what you want because it is reminding you that you forgot "something". So if you want to prevent this, you can check if your activity has a parent using the getParentActivityIntent()
method. If this returns null, you don't have specified the parent.
In this case you can fire the onBackPressed()
method that does basically the same as if the user would press the back button on the device. A good implementation that never crashes your app would be:
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
if (getParentActivityIntent() == null) {
Log.i(TAG, "You have forgotten to specify the parentActivityName in the AndroidManifest!");
onBackPressed();
} else {
NavUtils.navigateUpFromSameTask(this);
}
return true;
default:
return super.onOptionsItemSelected(item);
}
}
Please notice that the animation that the user sees is different between NavUtils.navigateUpFromSameTask(this);
and onBackPressed()
.
It is up to you which road you take, but I found the solution helpful, especially if you use a base class for all of your activities.
Solution 4 - Java
AndroidManifest file:
<activity android:name=".activity.DetailsActivity">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="br.com.halyson.materialdesign.activity.HomeActivity" />
</activity>
add in DetailsActivity:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
it's work :]
Solution 5 - Java
In the OnCreate
method add this:
if (getSupportActionBar() != null) {
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
Then add this method:
@Override
public boolean onSupportNavigateUp() {
onBackPressed();
return true;
}
Solution 6 - Java
Android Annotations:
@OptionsItem(android.R.id.home)
void homeSelected() {
onBackPressed();
}
Solution 7 - Java
I think onSupportNavigateUp()
is simplest and best way to do so
check the complete solution at the below stackoverflow answer. link: Click here for complete code
Solution 8 - Java
https://stackoverflow.com/a/46903870/4489222
To achieved this, there are simply two steps,
Step 1: Go to AndroidManifest.xml and in the add the parameter in tag - android:parentActivityName=".home.HomeActivity"
example :
<activity
android:name=".home.ActivityDetail"
android:parentActivityName=".home.HomeActivity"
android:screenOrientation="portrait" />
Step 2: in ActivityDetail add your action for previous page/activity
example :
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
onBackPressed();
return true;
}
return super.onOptionsItemSelected(item);}
}
Solution 9 - Java
Following Steps are much enough to back button:
Step 1: This code should be in Manifest.xml
<activity android:name=".activity.ChildActivity"
android:parentActivityName=".activity.ParentActivity"
android:screenOrientation="portrait">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value=".activity.ParentActivity" /></activity>
Step 2: You won't give
finish();
in your Parent Activity while starting Child Activity.
Step 3: If you need to come back to Parent Activity from Child Activity, Then you just give this code for Child Activity.
startActivity(new Intent(ParentActivity.this, ChildActivity.class));
Solution 10 - Java
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
in onCreated
method for the new apis.
Solution 11 - Java
If you are using Toolbar, I was facing the same issue. I solved by following these two steps
- In the AndroidManifest.xml
<activity android:name=".activity.SecondActivity" android:parentActivityName=".activity.MainActivity"/>
- In the SecondActivity, add these...
Toolbar toolbar = findViewById(R.id.second_toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayShowTitleEnabled(false);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
Solution 12 - Java
Building on Jared's answer, I had to enable and implement the action bar back button behavior in several activities and created this helper class to reduce code duplication.
public final class ActionBarHelper {
public static void enableBackButton(AppCompatActivity context) {
if(context == null) return;
ActionBar actionBar = context.getSupportActionBar();
if (actionBar == null) return;
actionBar.setDisplayHomeAsUpEnabled(true);
}
}
Usage in an activity:
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
...
ActionBarHelper.enableBackButton(this);
}
Solution 13 - Java
I was trying this myself and one thing that worked for me:
when(item.itemId) {
R.id.action_signup -> signup() //other menu item
android.R.id.home -> viewRoot.findNavController().navigateUp() //back
}
return super.onOptionsItemSelected(item)
}
I'm using a Jetpack navigation so that's the call to get the NavController.
Solution 14 - Java
Another option is to set the parentActivityName of the secondary activity to the MainActifity in your application Manifest file
<activity
android:name=".ServiceViewActivity"
android:parentActivityName=".MainActivity"/>