check maybe there is no breakage in your code. it sometimes happens when you skip some minor errors.

#Import_this

&lt;!-- language-all: lang-jsx --&gt;

    import {AppRegistry, Text, View, Button, StyleSheet} from &#39;react-native&#39;;

 

This my React Button code But style not working Hare ...

    &lt;Button
      onPress={this.onPress.bind(this)} 
      title={&quot;Go Back&quot;}
      style={{color: &#39;red&#39;, marginTop: 10, padding: 10}}
    /&gt;
Also I was try by this code 

    &lt;Button 
           containerStyle={{padding:10, height:45, overflow:&#39;hidden&#39;, 
           borderRadius:4, backgroundColor: &#39;white&#39;}}
           style={{fontSize: 20, color: &#39;green&#39;}} 
           onPress={this.onPress.bind(this)} title={&quot;Go Back&quot;}
          &gt; Press me!
    &lt;/Button&gt;


#Update Question:

Also I was try by This way..

 

    &lt;Button
    	onPress={this.onPress.bind(this)}
    	title={&quot;Go Back&quot;}
    	style={styles.buttonStyle}
    &gt;ku ka&lt;/Button&gt;

#Style

    const styles = StyleSheet.create({
        buttonStyle: {
            color: &#39;red&#39;,
            marginTop: 20,
            padding: 20,
            backgroundColor: &#39;green&#39;
        }
    });

But No out put: 
Screenshot  of my phone:-
[![Screenshot  of my phone:-][1]][1]


  [1]: https://i.stack.imgur.com/vaNeD.png

React-Native Button style not work

Is there any specific language implementation in Kotlin, which differs it from another languages implementation of coroutines? 

 - What means that coroutine is like light-weight thread?
 - What is the difference?
 - Are kotlin coroutines actually running in parallely / concurrently?
 - Even in multi-core system, there is only one coroutine running at any given time (is it right?)

Here I&#39;m starting 100000 coroutines, what happens behind this code? 

    for(i in 0..100000){
       async(CommonPool){
        //run long running operations
      }
    }

 

 


Difference between thread and coroutine in Kotlin

#### Steps to Reproduce / Screenshots

Apply all operations from [the instruction](https://nuclide.io/docs/platforms/react-native/):

1. Create a blank React Native project with `$ react-native init [project name].`

2. From the [command Palette][1] (Cmd-Shift-P), choose &quot;Nuclide React Native: Start Packager&quot; to start the React Native Server.

3. After starting the server, you can prime the React Native Debugger for when the application begins running. From the [command Palette][1] (Cmd-Shift-P), launch &quot;Nuclide React Native: Start Debugging&quot;.

4. Ensure that you are in the root directory of the React Native project, then run the application from the command-line: `$ react-native run-ios` (or choose another existing simulator, for example, `react-native run-ios --simulator=&quot;iPhone4s&quot;`).

 (**Important**: #4 should follow AFTER #3, and chrome debugger should be closed).

5. From the iOS simulator, press `Cmd-D` (`Ctrl-D` on Linux). This will bring up the debug options for your application. For example, select **Debug JS Remotely**.

#### Environment

* Atom version 1.15.0
* Nuclide plugin version 0.214.0
* React Native version: 0.42.3
* Platform(s) (iOS, Android, or both?): iOS
* Device info Simulator/Device? - Simulator iOS 10.2 / iOS 8.1
* OS version? - MacOS 10.12.3
* Debug/Release? - Debug

In [the same doc](https://nuclide.io/docs/platforms/react-native/) said: &quot;...After you enable debugging (#5) from the simulated application, Nuclide will attach to that debugging process automatically since we primed the Debugger above (#3).&quot; So before I clicked **Debug JS Remotely** I saw the working react app as expected:

[![working react app][2]][2]

And after I clicked **Debug JS Remotely** I see that the `Nuclide` debugger changed its status from **Starting debugger...** to **The debuggee is currently running.** as expected as well:

[![The debuggee is currently running][3]][3]

**BUT** after I click **Debug JS Remotely** I see ***white screen only***

[![white screen][4]][4]

And there are no errors. As soon as I turn off remote debugging, everything loads fine again.

This happens with Nuclide debugger only, with chrome debugger, everything works well.


  [1]: https://nuclide.io/docs/editor/basics/#command-palette
  [2]: https://i.stack.imgur.com/he3sc.png
  [3]: https://i.stack.imgur.com/YrUtv.png
  [4]: https://i.stack.imgur.com/QRnlM.png

React Native app stuck on blank white screen with remote debugging using Nuclide

<h6 id="steps-to-reproduce--screenshots"><a aria-hidden="true" tabindex="-1" href="#steps-to-reproduce--screenshots"></a>Steps to Reproduce / Screenshots</h6>
Apply all operations from <a href="https://nuclide.io/docs/platforms/react-native/" target="_blank" rel="noopener noreferrer">the instruction</a>:
<ol>
<li>
Create a blank React Native project with <code>$ react-native init [project name].</code>
</li>
<li>
From the <a href="https://nuclide.io/docs/editor/basics/#command-palette" target="_blank" rel="noopener noreferrer">command Palette</a> (Cmd-Shift-P), choose "Nuclide React Native: Start Packager" to start the React Native Server.
</li>
<li>
After starting the server, you can prime the React Native Debugger for when the application begins running. From the <a href="https://nuclide.io/docs/editor/basics/#command-palette" target="_blank" rel="noopener noreferrer">command Palette</a> (Cmd-Shift-P), launch "Nuclide React Native: Start Debugging".
</li>
<li>
Ensure that you are in the root directory of the React Native project, then run the application from the command-line: <code>$ react-native run-ios</code> (or choose another existing simulator, for example, <code>react-native run-ios --simulator="iPhone4s"</code>).
</li>
</ol>
(Important: #4 should follow AFTER #3, and chrome debugger should be closed).
<ol start="5">
<li>From the iOS simulator, press <code>Cmd-D</code> (<code>Ctrl-D</code> on Linux). This will bring up the debug options for your application. For example, select Debug JS Remotely.</li>
</ol>
<h6 id="environment"><a aria-hidden="true" tabindex="-1" href="#environment"></a>Environment</h6>
<ul>
<li>Atom version 1.15.0</li>
<li>Nuclide plugin version 0.214.0</li>
<li>React Native version: 0.42.3</li>
<li>Platform(s) (iOS, Android, or both?): iOS</li>
<li>Device info Simulator/Device? - Simulator iOS 10.2 / iOS 8.1</li>
<li>OS version? - MacOS 10.12.3</li>
<li>Debug/Release? - Debug</li>
</ul>
In <a href="https://nuclide.io/docs/platforms/react-native/" target="_blank" rel="noopener noreferrer">the same doc</a> said: "...After you enable debugging (#5) from the simulated application, Nuclide will attach to that debugging process automatically since we primed the Debugger above (#3)." So before I clicked Debug JS Remotely I saw the working react app as expected:
<a href="https://i.stack.imgur.com/he3sc.png" target="_blank" rel="noopener noreferrer"><img src="https://i.stack.imgur.com/he3sc.png" alt="working react app"></a>
And after I clicked Debug JS Remotely I see that the <code>Nuclide</code> debugger changed its status from Starting debugger... to The debuggee is currently running. as expected as well:
<a href="https://i.stack.imgur.com/YrUtv.png" target="_blank" rel="noopener noreferrer"><img src="https://i.stack.imgur.com/YrUtv.png" alt="The debuggee is currently running"></a>
BUT after I click Debug JS Remotely I see white screen only
<a href="https://i.stack.imgur.com/QRnlM.png" target="_blank" rel="noopener noreferrer"><img src="https://i.stack.imgur.com/QRnlM.png" alt="white screen"></a>
And there are no errors. As soon as I turn off remote debugging, everything loads fine again.
This happens with Nuclide debugger only, with chrome debugger, everything works well.

Is there an easy way to run a Python file inside Visual Studio Code with arguments?

I know I can add a custom configuration in the `launch.json` file with the `args` keyword. However, it is annoying to modify the *launch.json* file every time just because I want to use different arguments.




Visual Studio Code: run Python file with arguments

I&#39;m getting the following error immediately on launch, but only for devices running API &lt;20.

**edit: I initially reported this in Android Studio 2.4, and it&#39;s still an issue in Android Studio 3.0 stable


    D/dalvikvm: Trying to load lib /mnt/asec/[[packagename]]-1/lib/libsupportjni.so 0x41b13f30
    E/dalvikvm: dlopen(&quot;/mnt/asec/[[packagename]]-1/lib/libsupportjni.so&quot;) failed: dlopen failed: cannot locate symbol &quot;strtof&quot; referenced by &quot;libsupportjni.so&quot;...
    W/dalvikvm: Exception Ljava/lang/UnsatisfiedLinkError; thrown while initializing Lcom/android/tools/profiler/support/ProfilerService;
    D/AndroidRuntime: Shutting down VM
    W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x41659ce0)
    E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: [[packagename]], PID: 7500
                  java.lang.UnsatisfiedLinkError: dlopen failed: cannot locate symbol &quot;strtof&quot; referenced by &quot;libsupportjni.so&quot;...
                      at java.lang.Runtime.loadLibrary(Runtime.java:364)
                      at java.lang.System.loadLibrary(System.java:526)
                      at com.android.tools.profiler.support.ProfilerService.&lt;clinit&gt;(ProfilerService.java:44)
                      at [[packagename]].App.&lt;init&gt;(App.kt:25)
                      at java.lang.Class.newInstanceImpl(Native Method)
                      at java.lang.Class.newInstance(Class.java:1208)
                      at android.app.Instrumentation.newApplication(Instrumentation.java:990)
                      at android.app.Instrumentation.newApplication(Instrumentation.java:975)
                      at android.app.LoadedApk.makeApplication(LoadedApk.java:509)
                      at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4446)
                      at android.app.ActivityThread.access$1500(ActivityThread.java:144)
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1265)
                      at android.os.Handler.dispatchMessage(Handler.java:102)
                      at android.os.Looper.loop(Looper.java:136)
                      at android.app.ActivityThread.main(ActivityThread.java:5146)
                      at java.lang.reflect.Method.invokeNative(Native Method)
                      at java.lang.reflect.Method.invoke(Method.java:515)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:732)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:566)
                      at dalvik.system.NativeStart.main(Native Method)

UnsatisfiedLinkError: dlopen failed: cannot locate symbol &quot;strtof&quot; referenced by &quot;libsupportjni.so&quot; on API &lt;20

I have a list in which the first element is `null`. IntelliJ debugger correctly shows the list size as 5, but it shows only 1,2,3,4 elements. It would be nice to see that element with the index 0 is `null` (it took me some time to figure out my problems while debugging because it did not show that). Is it possible to force IntelliJ to show this?

Here is a screenshot, where the size is 5 and the elements shown are only 1-4 because the first element is `null`:

[![enter image description here][1]][1]


  [1]: https://i.stack.imgur.com/5D9pC.png

IntelliJ IDEA Debugger does not show null element in a list

How to enable &quot;Preserve Log&quot; in Network tools in Chrome developer tools by default? Everytime I press F12 and then select Network tab, I need to click preserve log checkbox to make it preserve request/responses. Is it possible to have it checked all the time by default?

[![enter image description here][1]][1]


By the way this feature works in &quot;Firefox Developer&quot; edition. When I click &quot;Persist Logs&quot; and close and then open the browser &amp; DEV tools window again, it is still checked.

[![enter image description here][2]][2]


# UPDATE - 6th March 2019

This will be fixed in Chrome 73. But if you want to try it before that then install **[Chrome Canary][3]**. It&#39;s working there. To enable/disable this persistence just go to [Dev tools settings][4] and check/uncheck Preserve Log under network section as shown below.

[![enter image description here][5]][5]

Thanks to the team for fixing it. Better late than never.


  [1]: https://i.stack.imgur.com/YC9dY.png
  [2]: https://i.stack.imgur.com/uZ6KP.png
  [3]: https://www.google.com/chrome/canary/
  [4]: https://developer.chrome.com/docs/devtools/customize/#settings
  [5]: https://i.stack.imgur.com/n6SfI.png

How to enable &quot;Preserve Log&quot; in Network tab in Chrome developer tools by default?

I just want to make VS Code&#39;s debugger work with webpack-dev-server without ignoring my breakpoints.

Now, webpack-dev-server serves the bundled files from memory, while, if I understand this correctly, the VS Code debugger searches for them on disk (...or not?...)

As a result, whenever I set a breakpoint I get the dreaded

`Breakpoint ignored because generated code not found (source map problem?)`

Now, every related question I could find had to do with typescript mostly, and not with the fact that webpack-dev-server serves from memory. I am not using typescript. Seems that people are either not using webpack-dev-server, or I am missing something blatantly obvious, with my money on the latter.

This is my VS Code `launch.json`


    {
      // Use IntelliSense to learn about possible attributes.
      // Hover to view descriptions of existing attributes.
      // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
      &quot;version&quot;: &quot;0.2.0&quot;,
      &quot;configurations&quot;: [
        {
          &quot;type&quot;: &quot;chrome&quot;,
          &quot;request&quot;: &quot;launch&quot;,
          &quot;name&quot;: &quot;Launch Chrome against localhost&quot;,
          &quot;url&quot;: &quot;http://localhost:8080&quot;,
          &quot;webRoot&quot;: &quot;${workspaceRoot}&quot;,
          &quot;sourceMaps&quot;: true,
          &quot;trace&quot;: true
        }
      ]
    }


and these are the related lines from my `webpack.config.js`


      devtool: &#39;cheap-module-source-map&#39;,
      output: {
        path: path.join(__dirname, &#39;dist&#39;),
        filename: &#39;[name].[chunkhash].js&#39;
      },


I have tried various modifications to the `launch.json` to no avail, so I am just pasting it in vanilla form. 

Note that the `output.path` is only used when there is a production build and the files are spewed to disk. 

Here is what the structure of the files is in the served page: 

[![enter image description here][1]][1]

And here is the command I am running in development

      &quot;scripts&quot;: {
        &quot;start&quot;: &quot;webpack-dev-server --host 0.0.0.0 --config ./webpack.config.js&quot;
      },

Finally, here is a relevant chunk from the trace file

    From target: {&quot;method&quot;:&quot;Debugger.scriptParsed&quot;,&quot;params&quot;:{&quot;scriptId&quot;:&quot;30&quot;,&quot;url&quot;:&quot;http://localhost:8080/manifest.0ec68ebd5f0abf9b4cd4.js&quot;,&quot;startLine&quot;:0,&quot;startColumn&quot;:0,&quot;endLine&quot;:150,&quot;endColumn&quot;:57,&quot;executionContextId&quot;:2,&quot;hash&quot;:&quot;216099518F33D6091EC12795265804FB35669A30&quot;,&quot;executionContextAuxData&quot;:{&quot;isDefault&quot;:true,&quot;frameId&quot;:&quot;18228.1&quot;},&quot;isLiveEdit&quot;:false,&quot;sourceMapURL&quot;:&quot;manifest.0ec68ebd5f0abf9b4cd4.js.map&quot;,&quot;hasSourceURL&quot;:false,&quot;isModule&quot;:false,&quot;length&quot;:5906}}
    Paths.scriptParsed: could not resolve http://localhost:8080/manifest.0ec68ebd5f0abf9b4cd4.js to a file under webRoot: e:\Mitch\Workspace\Projects\project-name. It may be external or served directly from the server&#39;s memory (and that&#39;s OK).
    SourceMaps.getMapForGeneratedPath: Finding SourceMap for http://localhost:8080/manifest.0ec68ebd5f0abf9b4cd4.js by URI: manifest.0ec68ebd5f0abf9b4cd4.js.map and webRoot: e:\Mitch\Workspace\Projects\project-name
    SourceMaps.loadSourceMapContents: Downloading sourcemap file from http://localhost:8080/manifest.0ec68ebd5f0abf9b4cd4.js.map
    To client: {&quot;seq&quot;:0,&quot;type&quot;:&quot;event&quot;,&quot;event&quot;:&quot;script&quot;,&quot;body&quot;:{&quot;reason&quot;:&quot;new&quot;,&quot;script&quot;:{&quot;id&quot;:1,&quot;source&quot;:{&quot;name&quot;:&quot;manifest.0ec68ebd5f0abf9b4cd4.js&quot;,&quot;path&quot;:&quot;http://localhost:8080/manifest.0ec68ebd5f0abf9b4cd4.js&quot;,&quot;sourceReference&quot;:1001}}}}
    To client: {&quot;seq&quot;:0,&quot;type&quot;:&quot;event&quot;,&quot;event&quot;:&quot;scriptLoaded&quot;,&quot;body&quot;:{&quot;path&quot;:&quot;http://localhost:8080/manifest.0ec68ebd5f0abf9b4cd4.js&quot;}}
    SourceMap: creating for http://localhost:8080/manifest.0ec68ebd5f0abf9b4cd4.js
    SourceMap: sourceRoot: 
    SourceMap: sources: [&quot;webpack:///webpack/bootstrap 7617f9bf7c8b0bc95159&quot;]
    SourceMap: webRoot: e:\Mitch\Workspace\Projects\project-name
    SourceMap: no sourceRoot specified, using webRoot + script path dirname: e:\Mitch\Workspace\Projects\project-name\
    SourceMap: mapping webpack:///webpack/bootstrap 7617f9bf7c8b0bc95159 =&gt; webpack\bootstrap 7617f9bf7c8b0bc95159, via sourceMapPathOverrides entry - &quot;webpack:///*&quot;: &quot;*&quot;
    SourceMaps.scriptParsed: http://localhost:8080/manifest.0ec68ebd5f0abf9b4cd4.js was just loaded and has mapped sources: [&quot;webpack\\bootstrap 7617f9bf7c8b0bc95159&quot;]


  [1]: https://i.stack.imgur.com/M8CQl.png

How to use VS Code debugger with webpack-dev-server (breakpoints ignored)

I am trying to open google maps or maps in my `react-native` application.

When I run the app on my iPhone/simulator, I receive this error
```
&quot;Don&#39;t know how to open URI:...&quot;.
```

What I am doing wrong?

My code:
```javascript
    openGps() {
      var url = &#39;geo:37.484847,-122.148386&#39;
      this.openExternalApp(url)
    }
    
    openExternalApp(url) {
      Linking.canOpenURL(url).then(supported =&gt; {
        if (supported) {
          Linking.openURL(url);
        } else {
          console.log(&#39;Don\&#39;t know how to open URI: &#39; + url);
        }
      });
    }
```

open maps/google maps in react native

I am not able to run the sample react Native AwesomeProject project.

Can anyone help? Below is the details. 

&gt;C:\Users\dip\AwesomeProject&gt;react-native run-android
&#39;yarn&#39; is not recognized as an internal or external command,
operable program or batch file.  
Scanning 557 folders for symlinks in C:\Users\dip\AwesomeProject\node_mo
ules (31ms)  
JS server already running.  
Building and installing the app on the device (cd android &amp;&amp; gradlew.bat instal
Debug)...  
Error occurred during initialization of VM  
java/lang/NoClassDefFoundError: java/lang/Object  
Could not install the app on the device, read the error above for details.
Make sure you have an Android emulator running or a device connected and have
set up your Android development environment:  
https://facebook.github.io/react-native/docs/android-setup.html

React Native Error - yarn&#39; is not recognized as an internal or external command

React-navigation docs are still young, and reading through the issues is not working quite much for me (changes on each version) does anyone have a working method to center title in Android using `react-navigation` in React Native?

How can we center title of react-navigation header?

I&#39;ve tried [react-native-hr][1] package - doesn&#39;t work for me nor on Android nor on iOS.

Following code is also not suitable because it renders three dots at the end

    &lt;Text numberOfLines={1}}&gt;               
        ______________________________________________________________
    &lt;/Text&gt;


  [1]: https://github.com/Riglerr/react-native-hr

Draw horizontal rule in React Native

Unlike ListView we can update this.state.datasource. Is there any method or example to update FlatList or re-render it?

My goal is to update the text value when user press button ...

    renderEntries({ item, index }) {
        return(
            &lt;TouchableHighlight onPress={()=&gt; this.setState({value: this.state.data[index].value+1})&gt;
                 &lt;Text&gt;{this.state.data[index].value}&lt;/Text&gt;
            &lt;/TouchableHighlight&gt;
        )
    }
    
    &lt;FlatList 
        ref={(ref) =&gt; { this.list = ref; }} 
        keyExtractor={(item) =&gt; item.entry.entryId} 
        data={this.state.data} 
        renderItem={this.renderEntries.bind(this)} 
        horizontal={false} /&gt;

Content Type	Original Author	Original Content on Stackoverflow
Question	Stich	View Question on Stackoverflow
Solution 1 - Debugging	Paul	View Answer on Stackoverflow

React Native app stuck on blank white screen with remote debugging using Nuclide

Debugging Problem Overview

Steps to Reproduce / Screenshots

Environment

Debugging Solutions

Solution 1 - Debugging

Difference between thread and coroutine in Kotlin

React-Native Button style not work

Attributions