Xamarin.UWP DryIoC error: Code generation not supported on this platform

If you are getting the following error when using DryIoC with Xamarin.Forms on UWP:

System.PlatformNotSupportedException: Dynamic code generation is not
supported on this platform.
at System.Reflection.Emit. TypeBuilder.GetMethod (Type, Methodinfo) + 0x2d
at
Dryloc.FastExpressionCompiler.LightExpression.ExpressionCompiler.CompileNoA
rgsNew(Constructorlnfo, Type, Type[, Type) + 0x5b
at
Dryloc.FastExpressionCompiler.LightExpression.ExpressionCompiler.TryCompileB
oundToFirstClosureParam(Type, Expression, IParameterProvider, Typel, Type.
CompilerFlags) + 0x73
at Dryloc.FactoryDelegateCompiler.CompileToFactoryDelegate(Expression.
Boolean) + 0x14c
at Dryloc.Container.Dryloc.IResolver.Resolve(Type, IfUnresolved) + 0x23c

Then instantiate your container with this code:

Container = new Container(rules =>
{
    // https://github.com/dadhi/DryIoc/blob/master/docs/DryIoc.Docs/ResolutionPipeline.md
    return rules.WithUseInterpretation();
});

The reason why you need to do this is here: DryIoc/ResolutionPipeline.md at master · dadhi/DryIoc · GitHub

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Xamarin.Forms: Android app forgets the style when using DynamicResource

If you break the look and feel of the app when you switch apps on mobile, and you use styles as DynamicResources, which you add as MergedDictionaries in App.Xaml,
you should pay attention to this:

When you don’t exit the Android app, but bring it back to the foreground after a very long time, the constructor logic in App.xaml.cs runs again. Don’t forget to add MergedDictionary from code, which contains the styles. If you forget this, all controls will appear in the app with their default look.

I wrote about how to handle restarting the application here: https://www.banditoth.hu/2021/03/22/xamarin-forms-reopening-application-best-pratices/

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Xamarin.Forms : Focus to the entry and set the cursor after the last character

If you want to make the cursor in Xamarin.Forms Entry blink behind the text you have already typed, instead of in front of it, after focusing, you need to do the following:

Subscribe to the Focused event of the Entry and modify the eventhandler as follows:

		public void OnEntryFocused(object sender, EventArgs args)
		{
			EntryInstance.CursorPosition = EntryInstance?.Text?.Length ?? 0;
		}

You can find more information about the CursorPosition at: https://docs.microsoft.com/en-us/dotnet/api/xamarin.forms.entry.cursorposition?view=xamarin-forms

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Xamarin.Android get resource id without ResourceManager.

If calling ResourceManager.GetResource(“resourceName”) doesn’t work because the framework doesn’t return the resource you want, you can bypass it with the following code snippet:

            string audioFileNameWithoutExtension = System.IO.Path.GetFileNameWithoutExtension(audiofile);
            int audioResourceId = (int)typeof(Resource.Raw).GetField(audioFileNameWithoutExtension).GetValue(null);
            Android.Net.Uri audioUri = Android.Net.Uri.Parse(ContentResolver.SchemeAndroidResource + "://" + Application.Context.PackageName + "/" + audioResourceId);

            channel.SetSound(audioUri, audioAttributes);

I used this code snippet to set a custom push notification sound

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Xamarin.Forms: ‘MSBuild:UpdateDesignTimeXaml’ code generator crashed solution

If you are facing an issue after updating the Xamarin.Forms version in your project, with the following error:

SOMEXAMLFILE.xaml: Error: The 'MSBuild:UpdateDesignTimeXaml' code generator crashed: Not connected
  at MonoDevelop.Core.Execution.RemoteProcessConnection.PostMessage (MonoDevelop.Core.Execution.BinaryMessage message, System.Threading.Tasks.TaskCompletionSource`1[TResult] cs, System.Boolean checkInitialized) [0x000c3] in /Users/builder/azdo/_work/2/s/main/src/core/MonoDevelop.Core/MonoDevelop.Core.Execution/RemoteProcessConnection.cs:438 
  at MonoDevelop.Core.Execution.RemoteProcessConnection.SendMessage (MonoDevelop.Core.Execution.BinaryMessage message) [0x00031] in /Users/builder/azdo/_work/2/s/main/src/core/MonoDevelop.Core/MonoDevelop.Core.Execution/RemoteProcessConnection.cs:385 
  at MonoDevelop.Projects.MSBuild.RemoteBuildEngineManager+<>c__DisplayClass20_0.<GetBuildEngine>b__5 () [0x00252] in /Users/builder/azdo/_work/2/s/main/src/core/MonoDevelop.Core/MonoDevelop.Projects.MSBuild/RemoteBuildEngineManager.cs:323 
  at MonoDevelop.Projects.MSBuild.RemoteBuildEngineManager.GetBuildEngine (MonoDevelop.Core.Assemblies.TargetRuntime runtime, System.String minToolsVersion, System.String solutionFile, System.String group, System.Object buildSessionId, System.Boolean setBusy, System.Boolean allowBusy) [0x0036f] in /Users/builder/azdo/_work/2/s/main/src/core/MonoDevelop.Core/MonoDevelop.Projects.MSBuild/RemoteBuildEngineManager.cs:273 
  at MonoDevelop.Projects.MSBuild.RemoteBuildEngineManager.GetRemoteProjectBuilder (System.String projectFile, System.String solutionFile, MonoDevelop.Core.Assemblies.TargetRuntime runtime, System.String minToolsVersion, System.Object buildSessionId, System.Boolean setBusy, System.Boolean allowBusy) [0x000df] in /Users/builder/azdo/_work/2/s/main/src/core/MonoDevelop.Core/MonoDevelop.Projects.MSBuild/RemoteBuildEngineManager.cs:176 [...]

Then clean your solution, and restart Visual Studio for Mac.

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