Tools --&gt; Options --&gt; Xamarin

Under &quot;iOS Settings&quot; and &quot;Android Settings&quot; there is a link for &quot;Check Now&quot; next to the Updates settings

[![enter image description here][1]][1]


  [1]: http://i.stack.imgur.com/feq7k.png

You might want to update to Beta release if you need the latest components - 

Goto VS 2015 -&gt; Tools -&gt; Option -&gt; Xamarin -&gt; Others -&gt; Check Now

[![enter image description here][1]][1]


  [1]: http://i.stack.imgur.com/8QdBS.png

They moved the &quot;Check Now&quot; into the harder-to-find `Tools/Options/Xamarin/Other`.  We must always be on guard when dealing with the 

&gt; Other

 [![Watch for the exciting new location][1]][1]


  [1]: https://i.stack.imgur.com/j0Sbl.png

In newer Version of Visual studio this option is available in `Other` node 

Goto VS 2015 -&gt; Tools -&gt; Options -&gt; Xamarin -&gt; Other -&gt; Check Now

[![enter image description here][1]][1]


  [1]: http://i.stack.imgur.com/yGicX.png
 Here you can choose between **Alpha, Beta or Stable** versions of `xamarin for Visual Studio`.

Apparently, my problem was solved after installing SDK Platform for Android 6.0 or API 23. API 24 or higher i.e Android 7.0 (Nougat) didnt run. If still not solved then install SDK Platform for even lower APIs like 22,21 ...
Hope it helps.

I am trying to send an Ajax request to a Tomcat server from my application, but I am getting this error (my web app is running on Chrome):

&gt;Response to preflight request doesn&#39;t pass access control check: No &#39;Access-Control-Allow-Origin&#39; header is present on the requested resource. Origin &#39;null&#39; is therefore not allowed access. The response had HTTP status code 403.

I have tried using

    &#39;Access-Control-Allow-Origin&#39; : &#39;http://localhost:8080/app&#39;,

but it didn&#39;t work.

My Ajax code:

     var arr = [1];
       $.ajax({ 
       url: &#39;http://localhost:8080/app&#39;,
       type: &#39;POST&#39;,
       contentType:&#39;application/json&#39;,
       headers: {
       &#39;Access-Control-Allow-Origin&#39; : &#39;http://localhost:8080&#39;,
       },
           data: JSON.stringify(arr[0]),
           success: function(data){
            //On ajax success do this
                 alert(data);
              }
         });

Getting request doesn&#39;t pass access control check: No &#39;Access-Control-Allow-Origin&#39; header is present on the requested resource

I&#39;m developing a web app at work in React/Redux/Webpack and am now starting to integrate testing with Mocha.

I followed [the instructions for writing tests in the Redux documentation][1], but now I have run into an issue with my webpack aliases.

For example, take a look at the imports section of this test for one of my action creators:

    import expect       from &#39;expect&#39;                 // resolves without an issue
    import * as actions from &#39;actions/app&#39;;           // can&#39;t resolve this alias
    import * as types   from &#39;constants/actionTypes&#39;; // can&#39;t resolve this alias
    
    describe(&#39;Actions&#39;, () =&gt; {
      describe(&#39;app&#39;,() =&gt; {
        it(&#39;should create an action with a successful connection&#39;, () =&gt; {
    
          const host = &#39;***************&#39;,
                port = ****,
                db = &#39;******&#39;,
                user = &#39;*********&#39;,
                pass = &#39;******&#39;;
         
          const action = actions.createConnection(host, port, db, user, pass);
    
          const expectedAction = {
            type: types.CREATE_CONNECTION,
            status: &#39;success&#39;,
            payload: { host, port, database, username }
          };
    
          expect(action).toEqual(expectedAction);
        });
      });
    });

As the comments suggest, mocha isn&#39;t able to resolve my import statements when they are referencing aliased dependencies. 

Because I&#39;m still new to webpack, here&#39;s my `webpack.config.js`:

    module.exports = {
      devtool: &#39;eval-source-map&#39;,
      entry: [
        &#39;webpack-hot-middleware/client&#39;,
        &#39;./src/index&#39;
      ],
      output: {
        path: path.join(__dirname, &#39;dist&#39;),
        filename: &#39;bundle.js&#39;,
        publicPath: &#39;/static/&#39;
      },
      resolve: {
        extensions : [&#39;&#39;, &#39;.js&#39;, &#39;.jsx&#39;],
        alias: {
          actions: path.resolve(__dirname, &#39;src&#39;, &#39;actions&#39;),
          constants: path.resolve(__dirname, &#39;src&#39;, &#39;constants&#39;),
          /* more aliases */
        }
      },
      plugins: [
        new webpack.optimize.OccurenceOrderPlugin(),
        new webpack.HotModuleReplacementPlugin(),
        new webpack.NoErrorsPlugin()
      ],
      module: {
        loaders: [{
          test: /\.js$/,
          loaders: [&#39;babel&#39;],
          exclude: /node_modules/,
          include: __dirname
        }]
      }
    };

Also, I&#39;m using the command `npm test` to run mocha, here&#39;s the script I&#39;m using in my `package.json`.

     {   
       &quot;scripts&quot;: {
         &quot;test&quot;: &quot;mocha ./src/**/test/spec.js --compilers js:babel-core/register --recursive&quot;
       }
     }

So here&#39;s where I get stuck. **I need to include the aliases from webpack into mocha when it runs.** 

  [1]: http://rackt.org/redux/docs/recipes/WritingTests.html

Using webpack aliases in mocha tests

I&#39;ve recently installed Visual Studio Community 2015 and I&#39;ve been following an MSDN tutorial [&quot;Build cross-platform apps with Xamarin&quot;][1]. When its time to design the look of the app and I select the Main.axml file in the Resources\layout folder, the Android designer fails with: 

**The installed Android SDK is too old. Version 24.3.4 or newer is required. Please update to the latest version.** 

I&#39;ve done a lot of searching and found that one of the newer versions of Android SDK caused the Xamarin Android designer to fail. I did find a version 24.4.1 that suggests this designer problem is fixed. 

How do I update this part of Visual Studio (i.e. Xamarin.Android)? Here is a snippet of my install on Windows 7:
[![enter image description here][2]][2]


  [1]: https://msdn.microsoft.com/library/dn879698%28v=vs.140%29.aspx?f=255&amp;MSPPError=-2147217396
  [2]: http://i.stack.imgur.com/K74J4.png

How to update Xamarin for Android within Visual Studio Community 2015

I've recently installed Visual Studio Community 2015 and I've been following an MSDN tutorial <a href="https://msdn.microsoft.com/library/dn879698%28v=vs.140%29.aspx?f=255&#x26;MSPPError=-2147217396" target="_blank" rel="noopener noreferrer">"Build cross-platform apps with Xamarin"</a>. When its time to design the look of the app and I select the Main.axml file in the Resources\layout folder, the Android designer fails with:
The installed Android SDK is too old. Version 24.3.4 or newer is required. Please update to the latest version.
I've done a lot of searching and found that one of the newer versions of Android SDK caused the Xamarin Android designer to fail. I did find a version 24.4.1 that suggests this designer problem is fixed.
How do I update this part of Visual Studio (i.e. Xamarin.Android)? Here is a snippet of my install on Windows 7:
<a href="http://i.stack.imgur.com/K74J4.png" target="_blank" rel="noopener noreferrer"><img src="http://i.stack.imgur.com/K74J4.png" alt="enter image description here"></a>

Using **Travis CI** for an existing Android project calling 

    $ ./gradlew build connectedCheck

 I get this error:

    /home/travis/build.sh: line 45: ./gradlew: Permission denied
    The command &quot;./gradlew build connectedCheck&quot; failed and exited with 126 during .


Travis.yml ./gradlew : Permission denied

I have the following code for a `RecyclerView.Adapter` class and it works fine:


    public class MyAdapter extends RecyclerView.Adapter&lt;MyAdapter.Viewholder&gt; {
    
        private List&lt;Information&gt; items;
        private int itemLayout;
    
        public MyAdapter(List&lt;Information&gt; items, int itemLayout){
            this.items = items;
            this.itemLayout = itemLayout;
        }
    
        @Override
        public Viewholder onCreateViewHolder(ViewGroup parent, int viewType) {
            View v = LayoutInflater.from(parent.getContext()).inflate(itemLayout, parent, false);
            return new Viewholder(v);
        }
    
        @Override
        public void onBindViewHolder(Viewholder holder, final int position) {
            Information item = items.get(position);
            holder.textView1.setText(item.Title);
            holder.textView2.setText(item.Date);
    
            holder.itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    Toast.makeText(view.getContext(), &quot;Recycle Click&quot; + position, Toast.LENGTH_SHORT).show();
                }
            });

           holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
           @Override
           public boolean onLongClick(View v) {
              Toast.makeText(v.getContext(), &quot;Recycle Click&quot; + position, Toast.LENGTH_SHORT).show();
               return true;
           }
    });
        }
    
        @Override
        public int getItemCount() {
            return items.size();
        }
    
        public class Viewholder extends RecyclerView.ViewHolder {
            public  TextView textView1;
            public TextView textView2;

            public Viewholder(View itemView) {
                super(itemView);
                textView1=(TextView) itemView.findViewById(R.id.text1);
                textView2 = (TextView) itemView.findViewById(R.id.date_row);
    
            }
        }
    }

However, I believe it is bad practice to implement the OnClickListener in the `onBindViewHolder` method. Why is this bad practice, and what is a better alternative?

Why is adding an OnClickListener inside onBindViewHolder of a RecyclerView.Adapter considered bad practice?

I&#39;m using [google sign-in services][1] to authenticate users that use my app. I got it to work when I just requested email information

    GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                        .requestEmail().build();
Then, I figured out I also need to request ID token to be able to authenticate with my backend so I did:

    GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                        .requestIdToken(String.valueOf(R.string.server_client_id))
                        .requestEmail().build();

The problem is that it wouldn&#39;t let me log in after the changes. The status I keep getting each time I try to login is `Status{statusCode=unknown status code: 12501, resolution=null}`.

I&#39;ve been searching around and I found [this post][2] that is pretty much about the same thing. However, I didn&#39;t make any of the mistakes named by the people who answered, the oAuth Client ID in my dev console is for web application:
[![clientIDs][3]][3]
And `R.string.server_client_id` is the first client ID from the picture. the package names are of course correct in all placed otherwise it wouldn&#39;t even work without the token request. 2 people also suggested that the app needs to be signed for this to work, but googles documentation says that debug key should work too, and it doesn&#39;t make sense to make people sign the apps for debugging.

I&#39;ve been trying to figure this out for hours but with no success. What could be the problem? Please feel free to request more information I might have forgotten to put here.

  [1]: https://developers.google.com/identity/sign-in/android/start
  [2]: https://stackoverflow.com/questions/33583326/new-google-sign-in-android
  [3]: http://i.stack.imgur.com/QqzCY.png

Error 12501 authenticating with google sign-in

How to declare class field? Like we can have it in java:

    protected SharedPreferences mSharedPreferences;
And later in `onCreate()`:  

    mSharedPreferences = PreferenceManager.getDefaultSharedPreferences(this)

Now I can use it anywhere I want (in subclasses of this base activity).

I try to do same in Kotlin:

    protected var sharedPreferences : SharedPreferences

And in `onCreate()`:

    sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this)

But I get a warning: &quot;Property must be initialized or be abstract&quot;

Property must be initialized or be abstract

I have a simple app (needs user login with account). I provide some premium features for paid users, like more news content.

I need to record if the user has bought this item in my server database. When I provide data content to user&#39;s device, I can then check the user&#39;s status, and provide different content for paid user.

I checked the official Trivialdrive sample provided by Google, it does not provide any sample code for server-side verification, here are my questions.

 1. I found the sample use my app&#39;s public key inside to verify purchase, it looks not good, I think I can just move the verification process to my server combined with user login credentials to see whether the user purchase completed, and then update the database.
 2. Also there is [purchase API][1] I can use to query, what I need is to pass the user&#39;s purchaseToken into server.

I am not sure what method I should take to verify the user&#39;s purchase, and mark the user&#39;s status in my database, maybe both?

And I am afraid there is a situation, if a user bought this item from google play, but for some reason, just in that time, when my app launched verification to my server, **the network connection is down or my own server is down**, user just paid the money in google play but I did not record the purchase in my server? What should I do, How can I deal with this situation.


  [1]: http://developer.android.com/google/play/developer-api.html#subscriptions_api_overview

How to verify purchase for android app in server side (google play in app billing v3)

Is there any way using Xamarin Forms (not Android or iOS specific) to have a pop-up, like Android does with Toast, that needs no user interaction and goes away after a (short) period of time?  

From searching around all I&#39;m seeing are alerts that need user clicks to go away.

Toast equivalent for Xamarin Forms

**Is it possible to develop and build Linux applications with Xamarin with the same code base?**

After a few years with Ubuntu, my main OS right now is Windows again. But it&#39;s not impossible that I could switch to Mac.

Right now I have a bit of experience with Qt and no experience with Xamarin.
With Qt you can develop *on* Windows, Linux, and Mac and *for* Windows, Linux, Mac, iOS, Android, Windows Mobile, ... They are pretty clear about that.

Since Xamarin is free and open source now and I still don&#39;t have much experience in Qt, I&#39;m considering trying out Xamarin for cross platform development instead of Qt.

Not being able to release my software for Linux would be a deal breaker for me. Being able to develop on Linux would be nice, but is optional.
But after all my Google research, I could only find information and people asking for support to develop *on* Linux and not *for* Linux.

As far as I know, this shouldn&#39;t be a problem with Mono alone. But as far as I know Xamarin &gt; Mono and I don&#39;t get everything in Mono I could get in Xamarin.

I&#39;m also not sure how well-supported Mono will be in the future. For me it looks like Xamarin is much more important for Microsoft than Mono itself.

I&#39;m not sure if it&#39;s even possible, since Xamarin is based on Mono, but is it possible that Microsoft will at some point decide not to support Mono with .NET compatibility in the same way as Xamarin, or even cancel Mono as standalone completely?

So I&#39;m looking for one single framework for all desktop and mobile platforms I can rely on, and I want to know if Xamarin and/or Mono and and/or Xamarin + Mono could be an alternative to Qt before I go deeper into any of those solutions.

Can you develop Linux applications with Xamarin?

I&#39;m working on a project for iOS and I&#39;m doing the programming with Visual Studios and it connects to a mac server using Xamarin. I recently tried to add more views to the storyboard and an additional class. When I tried to build the code, I received this error. http://pastebin.com/Ub5s89aa This is what the output from the console. http://pastebin.com/fhWDy2cJ

I don&#39;t know what this error means and when I tried to look up any part of the error, nothing helped. I cleaned my builded and tried to rebuild, and I also closed Visual Studios and reopen it to see if that help, but it didn&#39;t. Has anyone else had this problem before?

Failed to find or create execution context for description &lt;IBCocoaTouchPlatformToolDescription: 0x7fa8bad9a6f0&gt;

Im new to android development
my app gets constantly killed when switching 11 times from activity and than it only says  

&gt; Fatal signal 6 (SIGABRT), code -6 in tid 9485 (Thread-141585)

 in my logcat.

What does this mean?


What is fatal signal 6 in android logcat

&gt; java.lang.OutOfMemoryError. Consider increasing the value of
&gt; $(JavaMaximumHeapSize). Java ran out of memory while executing
&gt; &#39;java.exe&#39;

I am getting out of memory exception in my visualstudio Xamarin Project Please help me how can i resolve this issue.

Getting OutOfMemoryException in Xamarin

I have read:
https://stackoverflow.com/questions/31452435/how-do-i-disable-vshub-exe-in-the-system-tray/32542835#32542835
and
https://connect.microsoft.com/VisualStudio/feedback/details/1919828/hundreds-of-calls-second-to-vshub-and-browserlink-is-off

I would prefer to not disable vshub; I just want it to be more quiet when I am using fiddler.  Right now it spams everything else out, and I cannot do general debugging.

Does anybody know a workaround?  Can I block vshub from showing up in fiddler without blocking the rest of locahost?  

visual studio 2015 vshub is spamming fiddler

When installing Visual Studio 2015 Community Edition on Windows 10, using the web installer, everything runs fine, however, the following packages fail to install:

 - Team Explorer for Visual Studio 2015 -&gt; Fatal Error
 - Microsoft NuGet - Visual Studio 2015 -&gt; Package Failed
 - Microsoft Visual Studio Connected Services -&gt; Packages Failed
 - Azure AD Authentication Connected Services -&gt; Packages Failed
 - Microsoft Azure Mobile Services Connected Service -&gt; Package Failed
 - Microsoft Azure Storage Connected Service -&gt; Packages Failed
 - Microsoft.VisualStudio.Office365 -&gt; Package Failed

I have attempted a few work around including uninstalling every Visual Studio Version on my system, manually deleting the files in `C:\ProgramData\Program Cache`, and even gone as far as to uninstall my Antivirus (AVG) having attempted to disable it and see if that works before hand. I even ran the command `fsutil behavior set SymlinkEvaluation L2L:1 L2R:1 R2L:1 R2R:1`

I have even tried to use the ISO but ran into the same issue.

Since I don&#39;t use either Azure or Team Explorer any solutions which mean I won&#39;t have access to them will suffice.

The log file that was generated by the Installer can be [found here][1] as it was over 65,000 characters long (just scroll to the bottom for all the fun).


  [1]: https://www.dropbox.com/s/16rvopot0w7y7kx/Visual%20Studio%20Log.txt?dl=0

Multiple Errors Installing Visual Studio 2015 Community Edition

In NuGet for Visual Studio 2015, what is the difference between **consolidate** and **update** actions? In both cases I select a specific version that I want to use in selected projects.

Nuget consolidate vs update

After updating to VS 2015 update 1, if I run a web project (MVC), stop the application, then try to run it again, VS stops and pops up a dialog claiming 

&gt; You are debugging a Release build of `&lt;myproject.dll&gt;`.
&gt; 
&gt; Using Just My Code with release builds using compiler optimizations results in a degraded debugging experience (e.g. breakpoints won&#39;t be hit).

The problem is I&#39;m _not running a release build._ I&#39;m clearly running the (same) debug build I just ran! Why does VS think I&#39;m running a release build? 

Cleaning the solution and re-running clears the error message, so something is hosed somewhere.

VS 2015 Update 1 - Claiming I am debugging a release build

I installed [Visual Studio Update 1][1] yesterday and now when running ASP.NET services locally on IIS (not the express version). I am seeing hundreds of requests per second to the address 

     http://localhost:49155/vshub/ca9dea4b016f45c68a6a8c1a07809eb4/DataWarehouseModule/dataWarehouse/getStatus/ 

What is causing this and is it preventable?


  [1]: https://www.visualstudio.com/en-us/news/vs2015-update1-vs.aspx

Visual Studio 2015 Update 1 spamming localhost

I replaced all the images everywhere (by this I mean in drawable folders and all Windows Assets folders and iOS Resources folder), but it still shows me the default Xamarin icon for the app. I tried this code, too, but it doesn&#39;t seem to work either. Can someone tell me the solution?

    [assembly: Application(Icon = &quot;@drawable/icon&quot;)]



How to change application icon in Xamarin.Forms?

The conda docs at http://conda.pydata.org/docs/using/envs.html explain how to share environments with other people.

However, the docs tell us this is not cross platform:

    NOTE: These explicit spec files are not usually cross platform, and      
    therefore have a comment at the top such as # platform: osx-64 showing the  
    platform where they were created. This platform is the one where this spec
    file is known to work. On other platforms, the packages specified might not
    be available or dependencies might be missing for some of the key packages
    already in the spec.

    NOTE: Conda does not check architecture or dependencies when installing 
    from an explicit specification file. To ensure the packages work correctly,
    be sure that the file was created from a working environment and that it is 
    used on the same architecture, operating system and platform, such as linux-
    64 or osx-64.

Is there a good method to share and recreate a conda environment in one platform (e.g. CentOS) in another platform (e.g. Windows)?

How to share conda environments across platforms

I&#39;m new to Flutter, was just wondering if it&#39;s possible. 

I&#39;ve tried building the demo code using intellij with given instruction (https://flutter.io/setup/). It runs well on android device, but can&#39;t find the option to compile and run on my iOS device.

Content Type	Original Author	Original Content on Stackoverflow
Question	John Adams	View Question on Stackoverflow
Solution 1 - Android	Jason	View Answer on Stackoverflow
Solution 2 - Android	Divyans Mahansaria	View Answer on Stackoverflow
Solution 3 - Android	Steve Rawlins	View Answer on Stackoverflow
Solution 4 - Android	Paramjit	View Answer on Stackoverflow
Solution 5 - Android	Sagaryal	View Answer on Stackoverflow

How to update Xamarin for Android within Visual Studio Community 2015

Android Problem Overview

Android Solutions

Solution 1 - Android

Solution 2 - Android

Solution 3 - Android

Solution 4 - Android

Solution 5 - Android

Using webpack aliases in mocha tests

Getting request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource

Attributions