That line historically represents the margin of A4 paper, which is useful only if you need to print the code. 
Old school says that you should keep your code inside that margin, to guarantee much portability.

But.. nowadays in the real life, it makes no sense to me! Because we always use advanced editors, bigger displays, and I never needed to print any single line of code.


So, if you want to do it:

### Newer versions

&gt; Editor -&gt; General -&gt; Appearance -&gt; Show hard wrap guide

### Older versions

&gt; Editor -&gt; General -&gt; Appearance -&gt; Show right margin

or

&gt; Editor -&gt; Appearance -&gt; Show right margin

### For Mac 
&gt;To remove line go to:-  Preference-&gt; Editor -&gt; General -&gt; Appearance -&gt; Show hard wrap and visual guides. Uncheck it to remove.

It is as follows in the newer version of Android Studio:
### Editor -&gt; General -&gt; Appearance -&gt; Show hard wrap guide ###

Android Studio has changed layout again, so you can find this option at:

**File -&gt; Settings -&gt; Editor -&gt; General -&gt; Appearance -&gt; Show hard wrap and visual guides**

As it is mentioned earlier, if your code is of that length, it is pretty obvious that it is not that readable, i.e. clean. Being old school, I keep it at 80 characters and spill occasionally. 

I am trying to migrate these two models:

    # models.py

    from django.db import models


    class Person(models.Model):
        name = models.CharField(max_length=64)


    class Person2Person(models.Model):
        person = models.ForeignKey(Person)
        friend = models.ForeignKey(Person)

But I have got this error:

    SystemCheckError: System check identified some issues:

    ERRORS:
    website.Person2Person.friend: (fields.E304) Reverse accessor for &#39;Person2Person.friend&#39; clashes with reverse accessor for &#39;Person2Person.person&#39;.
	    HINT: Add or change a related_name argument to the definition for &#39;Person2Person.friend&#39; or &#39;Person2Person.person&#39;.
    website.Person2Person.person: (fields.E304) Reverse accessor for &#39;Person2Person.person&#39; clashes with reverse accessor for &#39;Person2Person.friend&#39;.
	    HINT: Add or change a related_name argument to the definition for &#39;Person2Person.person&#39; or &#39;Person2Person.friend&#39;.

I want to make a relationship many-to-many in the model `Person`. Why is my code wrong? And how should I fix it?

fields.E304 Reverse accessor clashes in Django

I&#39;m trying to implement a custom Spring repository. I have the interface:

    public interface FilterRepositoryCustom {
        List&lt;User&gt; filterBy(String role);
    }

the implementation:

    public class FilterRepositoryImpl implements FilterRepositoryCustom {
    ...
    }

and the &quot;main&quot; repository, extending my custom repository:

    public interface UserRepository extends JpaRepository&lt;User, String&gt;, FilterRepositoryCustom {
    ...
    }

I&#39;m using Spring Boot and, according to the [docs][1]:

&gt; By default, Spring Boot will enable JPA repository support and look in
&gt; the package (and its subpackages) where @SpringBootApplication is
&gt; located.

When I run my application, I get this error:

&gt; org.springframework.data.mapping.PropertyReferenceException: No property filterBy found for type User!

  [1]: https://spring.io/guides/gs/accessing-data-jpa/

No property found for type... custom Spring Data repository

I don&#39;t know why but sometime in Android Studio Editor, it shows **vertical line** as shown in screenshot below.

Don&#39;t know about other editor but it happens in Android Studio.

&gt; **So why it is showing and how to hide it?**

[![Android Studio shows Vertical Line in Editor][1]][1]


  [1]: https://i.stack.imgur.com/pzTp8.png

Vertical Line in Android Studio

I don't know why but sometime in Android Studio Editor, it shows vertical line as shown in screenshot below.
Don't know about other editor but it happens in Android Studio.
> So why it is showing and how to hide it?
<a href="https://i.stack.imgur.com/pzTp8.png" target="_blank" rel="noopener noreferrer"><img src="https://i.stack.imgur.com/pzTp8.png" alt="Android Studio shows Vertical Line in Editor"></a>

I am playing around with Android Studio by testing some projects out from GitHub and when I try to emulate the apk, it does not let me choose an emulator.

It tells me:

&gt; Device supports x86, but APK only supports armeabi-v7a

Why does it do this?


What is the reason for the error &quot;Device supports x86, but APK only supports armeabi-v7a&quot;

The recyclerview layout is defined as 

         &lt;android.support.v7.widget.RecyclerView
                android:layout_marginTop=&quot;15dp&quot;
                android:id=&quot;@+id/call_detail_list&quot;
                android:scrollbars=&quot;vertical&quot;
                android:layout_width=&quot;match_parent&quot;
                android:layout_height=&quot;wrap_content&quot;
                tools:listitem=&quot;@layout/call_item&quot;
                /&gt;
In the preview, I can see the list items from the specified layout,
but the number of item is 10. Is there any way that can be changed?



How to specify list item count in preview of recyclerview in Android Studio?

&gt; Installation failed with message Invalid File:
&gt; K:\project\app\build\intermediates\split-apk\with_ImageProcessor\debug\slices\slice_0.apk.
&gt; It is possible that this issue is resolved by uninstalling an existing
&gt; version of the apk if it is present, and then re-installing.
&gt; 
&gt; WARNING: Uninstalling will remove the application data!
&gt; 
&gt; Do you want to uninstall the existing application?

i am running my project in android studio 2.3 beta 3 .

Installation failed with message Invalid File

I got the following Error in android Studio 2.2.3 when I sync gradle.

**Error:Cause: unable to find valid certification path to requested target**

How can I fix this issue

I am Adding my Gradle file also

    apply plugin: &#39;com.android.application&#39;
    android {
    compileSdkVersion 25
    buildToolsVersion &quot;25.0.2&quot;
    defaultConfig {
        applicationId &quot;com.sample.myapplication&quot;
        minSdkVersion 16
        targetSdkVersion 22
        versionCode 1
        versionName &quot;1.0&quot;
        testInstrumentationRunner &quot;android.support.test.runner.AndroidJUnitRunner&quot;
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile(&#39;proguard-android.txt&#39;), &#39;proguard-rules.pro&#39;
        }
    } } dependencies {
    compile fileTree(dir: &#39;libs&#39;, include: [&#39;*.jar&#39;])
    androidTestCompile(&#39;com.android.support.test.espresso:espresso-core:2.2.2&#39;, {
        exclude group: &#39;com.android.support&#39;, module: &#39;support-annotations&#39;
    })
    compile &#39;com.android.support:appcompat-v7:23.4.0&#39;
    compile &#39;com.android.support:design:23.4.0&#39;
    compile &#39;com.android.support:palette-v7:23.4.0&#39;
    testCompile &#39;junit:junit:4.12&#39;
    // FireBase
    compile &#39;com.google.firebase:firebase-messaging:9.0.0&#39;
    }//Add this line
    apply plugin: &#39;com.google.gms.google-services&#39;


and the project Level Gradle File
 

    buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath &#39;com.android.tools.build:gradle:2.2.3&#39;
		classpath &#39;com.google.gms:google-services:3.0.0&#39;
    }
    }
    allprojects {
    repositories {
        mavenCentral()
        jcenter{ url &quot;http://jcenter.bintray.com/&quot; }
        maven { url &quot;https://jitpack.io&quot; }
    }
    }
    task clean(type: Delete) {
    delete rootProject.buildDir
    }




Error:Cause: unable to find valid certification path to requested target

About every 4 second after I start the emulator device from my Android Studio project an error message is printed into the Run window. It&#39;s extremely annoying because it hijacks the focus. If I&#39;m in the Debug window it switches to the Run window every 4 seconds because of this error no matter what I do. 

This started a day ago, but I don&#39;t know what induced it. I use the same emulator devices for several months now. Maybe an upgrade of some portion of Android SDK? The external SDK Manager is not invokable any more.

[![enter image description here][1]][1]

-------------

The messages start to come right after I boot up this API 25 wear emulator. One workaround is to make that tab float, then it doesn&#39;t hijack my focus; I move it to my second monitor.

----------

I also noticed I cannot connect my Android Wear app running on my physical device (I&#39;m running physical phone with the emulated wear) with my emulator.

  [1]: https://i.stack.imgur.com/yDwxA.png

How to prevent Android Studio / AVD &quot;CANNOT TRANSLATE guest DNS ip&quot; error messages?

I can&#39;t find any way to surround a selection with something in VS Code.

For example doing something like that : `text` =&gt; `&quot;text&quot;` just by selecting the word text and typing key &lt;kbd&gt;&quot;&lt;/kbd&gt;

Another example with the following text :
```
mon
tue
wed
thu
fri
sat
sun```

By selecting all of theses words :

```
mon|
tue|
wed|
thu|
fri|
sat|
sun|```

and typing &lt;kbd&gt;&quot;&lt;/kbd&gt; I would like to perform something like this :

```
&quot;mon&quot;
&quot;tue&quot;
&quot;wed&quot;
&quot;thu&quot;
&quot;fri&quot;
&quot;sat&quot;
&quot;sun&quot;```

If someone have any idea.

Thanks.

Visual Studio Code Surround With

I&#39;m using Visual Studio Code for working and I use `ctrl-P` command to search for files in my directory.


The problem appears when I want to search for another file, it opens it in the place of the first searched file, closing it.

Is any setting for avoiding this pain?

Visual Studio Code closes my file when I search for new ones

Is it possible to move/open the terminal window to the right of the screen? That would allow me to optimize the editor spaces to work in more efficiently.

---

In vscode when we use &lt;kbd&gt;Ctrl&lt;/kbd&gt;+&lt;kbd&gt;I&lt;/kbd&gt; For example, open a terminal just below where the files are open, 

&lt;img src=&quot;https://i.stack.imgur.com/Mvncz.png&quot; width=&quot;300&quot; height=&quot;200&quot;/&gt;
 

  [1]: https://i.stack.imgur.com/Mvncz.png
  [2]: https://i.stack.imgur.com/PHGlS.png
  [3]: https://i.stack.imgur.com/Hfr5H.png

It is possible in vscode to put the terminal on the right?

is there a way to always ignore a folder... in project view.

I have multiple apps in one repo and have &#39;node_modules&#39; in each app 

    mainapp
    ├── microapp
    │	└── node_modules
    ├── microapp2
    │	└── node_modules
    ├── index
    ├── config
    └── assets

 
I want to exclude from search the `node_modules` folder when i search inside project in the above structure.


How do I exclude a folder from search in sublime text 3 permanently?

In the VSCode **editor** when you pull the **scroll bar** down to the bottom of the file, all you see is a **blank page**, since the text has scrolled up past the **top** of the text editor window. This makes scrolling to the bottom **difficult** because you can&#39;t just pull the scroll bar quickly all the way down but have to carefully position the cursor so you can still see your code.

Very similar to https://stackoverflow.com/questions/1747282/how-to-make-visual-studio-editor-stop-scrolling-past-bottom-of-a-file, but comments have pointed out that question/answer is for Visual Studio.  This answer is for VSCode on the macOS and Windows.

Content Type	Original Author	Original Content on Stackoverflow
Question	Jagruttam Panchal	View Question on Stackoverflow
Solution 1 - Android Studio	Luca Corradi	View Answer on Stackoverflow
Solution 2 - Android Studio	theThapa	View Answer on Stackoverflow
Solution 3 - Android Studio	Viktor Brešan	View Answer on Stackoverflow

Vertical Line in Android Studio

Android Studio Problem Overview

Android Studio Solutions

Solution 1 - Android Studio

Newer versions

Older versions

For Mac

Solution 2 - Android Studio

Editor -> General -> Appearance -> Show hard wrap guide

Solution 3 - Android Studio

No property found for type... custom Spring Data repository

fields.E304 Reverse accessor clashes in Django

Attributions