Developer technologies | .NET | .NET Multi-platform App UI
A Microsoft open-source framework for building native device applications spanning mobile, tablet, and desktop.
Missing class android.window.OnBackInvokedCallback (referenced from: android.window.OnBackInvokedCallback androidx.activity.OnBackPressedDispatcher.mOnBackInvokedCallback and 4 other contexts)
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(35.2, 55.00000000000001%, 13%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EY%3C/text%3E%3C/svg%3E)
YouBT
1
Reputation point
Hello!
I am new with dotnet MAUI, still learning while working. I am trying to build my Android Application, I use my physical Device (Android 6.0 API 23).
If I Debug or make Release the app is compiling and building without any errors and crashes and works on my other physical devices. But if I switch R8 (which I need for publishing in Google Play) it crashes. It couldn`t even load MainPage. Staying in Splash Screen and in Visual Studio 2022 Community edition I can see "Application in break mode".
I can`t fix this issue: Warrning: Missing class android.window.OnBackInvokedCallback (referenced from: android.window.OnBackInvokedCallback androidx.activity.OnBackPressedDispatcher.mOnBackInvokedCallback and 4 other contexts)
I installed latest Nuget packages and
Xamarin.AndroidX.Activity 1.6.1
Xamarin.AndroidX.Activity.Compose"1.6.1
Xamarin.AndroidX.Activity.Ktx 1.6.1
Xamarin.AndroidX.AppCompat 1.5.1.1
Xamarin.AndroidX.Core" 1.9.0.1
Xamarin.AndroidX.Legacy.Support.Core.UI" 1.0.0.16
Xamarin.AndroidX.Lifecycle.Runtime" 2.5.1.1
Xamarin.AndroidX.Navigation.Common 2.5.3
Xamarin.AndroidX.Navigation.Runtime 2.5.3
Xamarin.AndroidX.Window 1.0.0.10
Xamarin.AndroidX.Window.WindowExtensions 1.0.0.10-alpha01
But I still can`t solve this problem. I searched a lot, but had no luck to find the right solution.
If someone can help, I will be really thankfull!
Developer technologies | .NET | .NET Multi-platform App UI
Developer technologies | Visual Studio | Debugging
Developer technologies | Visual Studio | Debugging
A core feature of Visual Studio that allows developers to inspect, analyze, and troubleshoot code during execution.
Developer technologies | .NET | Other
Developer technologies | .NET | Other
Microsoft Technologies based on the .NET software framework. Miscellaneous topics that do not fit into specific categories.
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![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(128, 8%, 22%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EA%3C/text%3E%3C/svg%3E)
Anonymous2023-01-02T06:10:42.947+00:00 Do you follow this link when you release your application?
https://learn.microsoft.com/en-us/dotnet/maui/android/deployment/publish-cli?view=net-maui-7.0Did you install apk or abb file directly in your device?
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YouBT 1 Reputation point
2023-01-02T13:11:28.88+00:00 Hello!
Yes, I followed every step provided in this link. Release is completed without any errors and I install the apk file on my other Android devices and it works perfect, without any crashes.
But if I switch R8 I can`t make the release, because there are always Warnings for missing classes. I install new Xamarin.Androidx packages, but nothing helps.
This Warnings are from R8. I have proguard.cfg file configuarted as Proguard Configuration in my project:
-printconfiguration config_navigation.txt
-printseeds seeds.txt
-printusage usage.txt-printmapping mapping.txt
-keepattributes SourceFile
-keepattributes LineNumberTable-keepnames class ** { *; }
-keepclasseswithmembers class* { public <init>(android.window.OnBackInvokedCallback);
}I know that it is not recommended to Debug with R8 switched on but I tried and my App become in break mode with this message:
Java.Lang.ClassNotFoundException: 'Didn't find class "com.microsoft.maui.PlatformInterop" on path: DexPathList[[zip file "/data/app/com.companyname.my_app-1/base.apk"],nativeLibraryDirectories=[/data/app/com.companyname.my_app-1/lib/arm64, /data/app/com.companyname.my_app-1/base.apk!/lib/arm64-v8a, /vendor/lib64, /system/lib64]]
Today when I tried to make Release I got the same R8 Warning:
Missing class android.window.OnBackInvokedCallback (referenced from: android.window.OnBackInvokedCallback androidx.activity.OnBackPressedDispatcher.mOnBackInvokedCallback and 4 other contexts)ISometimes when I install other Xamarin.AndroidX package it shows the different class missing.
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![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(163.2, 33%, 25%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EGF%3C/text%3E%3C/svg%3E)
George Findulov 5 Reputation points2023-09-07T12:52:28.21+00:00 I had the exactly same problem, it turned out that I had enabled R8 for both Debug and Release.
When I removed this section from the *.csproj file, it started to work for me in Debug mode:
<PropertyGroup Condition="'$(Configuration)|$(TargetFramework)|$(Platform)'=='Debug|net7.0-android33.0|AnyCPU'"> <AndroidLinkTool>r8</AndroidLinkTool> </PropertyGroup>
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