dalvik | this is a fork of android dalvik | Plugin library

The change that happened in 3.6.0 was that android:extractNativeLibs default has changed:

The default value is "true" if extractNativeLibs is not configured in AndroidManifest.xml. However, when building your app using Android Gradle plugin 3.6.0 or higher, this property is reset to "false" if it is NOT configured in AndroidManifest.xml and minSdkVersion >= 23. If minSdkVersion < 23 and extractNativeLibs is explicitly set to "false" in AndroidManifest.xml, you must add the following to your app's build.gradle file:

Solution

For some reason I had put the onBackgroundMessageHandler as a class method in my project. The problem were resolved by simply placing the method as a top-level function as it should be.

Before

I have solved it.

1.add com.google.android.gms:play-services-ads in android/app/build.gradle dependencies { ...

How Android Runtime compile more efficient native code than CLang (Android NDK) C/C++ compiler?

The JIT compiler complements ART's current ahead-of-time (AOT) compiler and improves runtime performance.

Although JIT and AOT use the same compiler with a similar set of optimizations, the generated code might not be identical. JIT makes use of runtime type information can do better inlining and makes on stack replacement (OSR) compilation possible, all of which generate slightly different code.

Is there any performance advantage in writing native C/C++ code on recent Android OS versions?

Definitely yes for old Android devices. Old Android devices use Dalvik VM that interprets code. Java code will be 5-7 times slower than the same C/C++ code on Dalvik VM. But on ART, in most cases, Android Runtime profile-guided compilation generates much more efficient native code based on application execution statistics, but Java still ~30-35% slower than optimized C/C++ code on Android 8.1 and ~10-20% faster on Android 11.

https://source.android.com/devices/tech/dalvik/jit-compiler

Conclusion: In my humble opinion, there is no performance advantage in writing C/C++ code for recent Android devices (starting from v7.0 Nougat - ART VM), unless you're an experienced C/C++ developer and deeply understand CPU architecture, so you can do optimization much better than Android Runtime does.

Also, Android NDK (C/C++) is still the only way for Android Developers to:

1. Port your native C/C++ code to Android.
2. Use C/C++ game engines and libraries (like Vulkan or TensorFlow).
3. Use platform-specific APIs not available in Android SDK.

For this, you can check document Improve Xamarin.Forms App Performance.

Specially part: Optimize image resources:

Displaying image resources can greatly increase an application's memory footprint. Therefore, they should only be created when required and should be released as soon as the application no longer requires them. For example, if an application is displaying an image by reading its data from a stream, ensure that stream is created only when it's required, and ensure that the stream is released when it's no longer required. This can be achieved by creating the stream when the page is created, or when the Page.Appearing event fires, and then disposing of the stream when the Page.Disappearing event fires.

When downloading an image for display with the ImageSource.FromUri method, cache the downloaded image by ensuring that the UriImageSource.CachingEnabled property is set to true.

You can also try nuget Xamarin.FFImageLoading.Forms,which is a xamarin Library to load images quickly and easily on Xamarin.Forms. For more details,please check:https://github.com/luberda-molinet/FFImageLoading .

Step 1 :

create src\com\XLR folder in your App Directory

there create the file BootReceiver.java with the following content :

On C++ side (replace com_xxx_lib with your package id):

It was occurring because Unity was using Vulkan instead of OpenGLES all along. Disabling the Automatic Graphics API in the Player settings and dragging OpenGLES2 on top fixes the issue.

It is resolved by upgrading ktor version to 1.3.2 or higher