feat: add Android APK update sample with GeneralUpdate.Avalonia

UI/AndroidUpdate/AndroidUpdate.slnx

@@ -0,0 +1,3 @@
+<Solution>
+  <Project Path="src/AndroidUpdate.Android/AndroidUpdate.Android.csproj" />
+</Solution>

UI/AndroidUpdate/src/AndroidUpdate.Android/AndroidApp.cs

@@ -0,0 +1,33 @@
+using Android.App;
+using Android.Runtime;
+using AndroidUpdate.ViewModels;
+using Avalonia;
+using Avalonia.Android;
+
+namespace AndroidUpdate.Android;
+
+[global::Android.App.Application]
+public class AndroidApp : AvaloniaAndroidApplication<App>
+{
+    protected AndroidApp(nint javaReference, JniHandleOwnership transfer) : base(javaReference, transfer)
+    {
+        // Read real app version from package manager as early as possible
+        try
+        {
+            var pkgInfo = PackageManager?.GetPackageInfo(PackageName!, 0);
+            if (pkgInfo?.VersionName != null)
+                App.DeviceVersion = pkgInfo.VersionName;
+        }
+        catch { /* fallback to default "1.0.0.0" */ }
+    }
+
+    protected override AppBuilder CustomizeAppBuilder(AppBuilder builder)
+    {
+        // Register the Android-specific handler factory before Avalonia starts
+        App.HandlerFactory = (packageInfo, currentVersion) =>
+            new Services.AndroidUpdateHandler(packageInfo, currentVersion);
+
+        return base.CustomizeAppBuilder(builder)
+            .WithInterFont();
+    }
+}

UI/AndroidUpdate/src/AndroidUpdate.Android/AndroidUpdate.Android.csproj

@@ -0,0 +1,42 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net10.0-android</TargetFramework>
+    <SupportedOSPlatformVersion>23</SupportedOSPlatformVersion>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <LangVersion>latest</LangVersion>
+    <ApplicationId>com.generalupdate.androidupdate</ApplicationId>
+    <ApplicationVersion>7</ApplicationVersion>
+    <ApplicationDisplayVersion>1.0.0.0</ApplicationDisplayVersion>
+    <ApplicationTitle>AndroidUpdate</ApplicationTitle>
+    <AndroidPackageFormat>apk</AndroidPackageFormat>
+    <AndroidEnableProfiledAot>false</AndroidEnableProfiledAot>
+    <AvaloniaUseCompiledBindingsByDefault>true</AvaloniaUseCompiledBindingsByDefault>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Avalonia" Version="12.0.3" />
+    <PackageReference Include="Avalonia.Android" Version="12.0.3" />
+    <PackageReference Include="Avalonia.Themes.Fluent" Version="12.0.3" />
+    <PackageReference Include="Avalonia.Fonts.Inter" Version="12.0.3" />
+    <PackageReference Include="AvaloniaUI.DiagnosticsSupport" Version="2.2.1">
+      <IncludeAssets Condition="'$(Configuration)' != 'Debug'">None</IncludeAssets>
+      <PrivateAssets Condition="'$(Configuration)' != 'Debug'">All</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="CommunityToolkit.Mvvm" Version="8.4.0" />
+    <PackageReference Include="Xamarin.AndroidX.Core.SplashScreen" Version="1.0.1.15" />
+    <AndroidResource Include="Icon.png">
+      <Link>Resources\drawable\Icon.png</Link>
+    </AndroidResource>
+    <AndroidResource Include="Resources\xml\file_paths.xml" />
+    <AndroidResource Include="Resources\xml\network_security_config.xml" />
+  </ItemGroup>
+
+  <!-- Reference the compiled GeneralUpdate.Avalonia.Android DLL -->
+  <ItemGroup>
+    <Reference Include="GeneralUpdate.Avalonia.Android">
+      <HintPath>libs\GeneralUpdate.Avalonia.Android.dll</HintPath>
+    </Reference>
+  </ItemGroup>
+</Project>

UI/AndroidUpdate/src/AndroidUpdate.Android/App.axaml

@@ -0,0 +1,14 @@
+<Application xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:local="using:AndroidUpdate"
+             x:Class="AndroidUpdate.App"
+             RequestedThemeVariant="Default">
+
+    <Application.DataTemplates>
+        <local:ViewLocator/>
+    </Application.DataTemplates>
+
+    <Application.Styles>
+        <FluentTheme />
+    </Application.Styles>
+</Application>

UI/AndroidUpdate/src/AndroidUpdate.Android/App.axaml.cs

@@ -0,0 +1,59 @@
+using System;
+using System.Net.Http;
+using AndroidUpdate.ViewModels;
+using Avalonia;
+using Avalonia.Controls.ApplicationLifetimes;
+using Avalonia.Markup.Xaml;
+
+namespace AndroidUpdate;
+
+public partial class App : Avalonia.Application
+{
+    /// <summary>
+    /// Static factory for creating platform-specific update handlers.
+    /// Set by the Android project (or other platform projects) during startup.
+    /// </summary>
+    public static Func<PackageInfo, string, IAndroidUpdateHandler>? HandlerFactory { get; set; }
+
+    /// <summary>
+    /// The device's currently installed app version.
+    /// Set by the platform project on startup; falls back to "1.0.0.0".
+    /// </summary>
+    public static string DeviceVersion { get; set; } = "1.0.0.0";
+
+    public override void Initialize()
+    {
+        AvaloniaXamlLoader.Load(this);
+    }
+
+    public override void OnFrameworkInitializationCompleted()
+    {
+        var httpClient = new HttpClient();
+        httpClient.Timeout = TimeSpan.FromSeconds(30);
+
+        MainViewViewModel CreateViewModel() =>
+            new(httpClient, (pkg, ver) =>
+            {
+                if (HandlerFactory == null)
+                    throw new InvalidOperationException(
+                        "HandlerFactory not set. Ensure the platform project initializes it.");
+                return HandlerFactory(pkg, ver);
+            });
+
+        if (ApplicationLifetime is IActivityApplicationLifetime singleViewFactory)
+        {
+            // Android: use MainViewFactory for Activity-based lifetime
+            singleViewFactory.MainViewFactory = () =>
+                new Views.MainView { DataContext = CreateViewModel() };
+        }
+        else if (ApplicationLifetime is ISingleViewApplicationLifetime singleViewPlatform)
+        {
+            singleViewPlatform.MainView = new Views.MainView
+            {
+                DataContext = CreateViewModel()
+            };
+        }
+
+        base.OnFrameworkInitializationCompleted();
+    }
+}

UI/AndroidUpdate/src/AndroidUpdate.Android/MainActivity.cs

@@ -0,0 +1,15 @@
+using Android.App;
+using Android.Content.PM;
+using Avalonia;
+using Avalonia.Android;
+
+namespace AndroidUpdate.Android;
+
+[Activity(
+    Label = "AndroidUpdate",
+    Theme = "@style/MyTheme.NoActionBar",
+    MainLauncher = true,
+    ConfigurationChanges = ConfigChanges.Orientation | ConfigChanges.ScreenSize | ConfigChanges.UiMode)]
+public class MainActivity : AvaloniaMainActivity
+{
+}

UI/AndroidUpdate/src/AndroidUpdate.Android/Properties/AndroidManifest.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+          package="com.generalupdate.androidupdate"
+          android:versionCode="7"
+          android:versionName="1.0.0.0">
+  <uses-sdk android:minSdkVersion="23" android:targetSdkVersion="36" />
+  <application android:label="AndroidUpdate"
+               android:theme="@style/MyTheme.NoActionBar"
+               android:usesCleartextTraffic="true">
+    <!-- FileProvider for APK installation -->
+    <provider android:name="androidx.core.content.FileProvider"
+              android:authorities="com.generalupdate.androidupdate.fileprovider"
+              android:exported="false"
+              android:grantUriPermissions="true">
+      <meta-data android:name="android.support.FILE_PROVIDER_PATHS"
+                 android:resource="@xml/file_paths" />
+    </provider>
+  </application>
+  <!-- Required for APK installation on Android 8+ -->
+  <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
+  <!-- Internet access for downloading updates -->
+  <uses-permission android:name="android.permission.INTERNET" />
+  <!-- Write external storage for download directory -->
+  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"
+                   android:maxSdkVersion="28" />
+</manifest>

UI/AndroidUpdate/src/AndroidUpdate.Android/Resources/drawable-night-v31/avalonia_anim.xml

@@ -0,0 +1,66 @@
+<animated-vector
+  xmlns:android="http://schemas.android.com/apk/res/android"
+  xmlns:aapt="http://schemas.android.com/aapt">
+  <aapt:attr name="android:drawable">
+    <vector
+      android:name="vector"
+      android:width="128dp"
+      android:height="128dp"
+      android:viewportWidth="128"
+      android:viewportHeight="128">
+      <group
+        android:name="wrapper"
+        android:translateX="21"
+        android:translateY="21">
+        <group android:name="group">
+          <path
+            android:name="path"
+            android:pathData="M 74.853 85.823 L 75.368 85.823 C 80.735 85.823 85.144 81.803 85.761 76.602 L 85.836 41.76 C 85.225 18.593 66.254 0 42.939 0 C 19.24 0 0.028 19.212 0.028 42.912 C 0.028 66.357 18.831 85.418 42.18 85.823 L 74.853 85.823 Z"
+            android:strokeWidth="1"/>
+          <path
+            android:name="path_1"
+            android:pathData="M 43.059 14.614 C 29.551 14.614 18.256 24.082 15.445 36.743 C 18.136 37.498 20.109 39.968 20.109 42.899 C 20.109 45.831 18.136 48.301 15.445 49.055 C 18.256 61.716 29.551 71.184 43.059 71.184 C 47.975 71.184 52.599 69.93 56.628 67.723 L 56.628 70.993 L 71.344 70.993 L 71.344 44.072 C 71.357 43.714 71.344 43.26 71.344 42.899 C 71.344 27.278 58.68 14.614 43.059 14.614 Z M 29.51 42.899 C 29.51 35.416 35.576 29.35 43.059 29.35 C 50.541 29.35 56.607 35.416 56.607 42.899 C 56.607 50.382 50.541 56.448 43.059 56.448 C 35.576 56.448 29.51 50.382 29.51 42.899 Z"
+            android:strokeWidth="1"
+            android:fillType="evenOdd"/>
+          <path
+            android:name="path_2"
+            android:pathData="M 18.105 42.88 C 18.105 45.38 16.078 47.407 13.579 47.407 C 11.079 47.407 9.052 45.38 9.052 42.88 C 9.052 40.381 11.079 38.354 13.579 38.354 C 16.078 38.354 18.105 40.381 18.105 42.88 Z"
+            android:strokeWidth="1"/>
+        </group>
+      </group>
+    </vector>
+  </aapt:attr>
+  <target android:name="path">
+    <aapt:attr name="android:animation">
+      <objectAnimator
+        android:propertyName="fillColor"
+        android:duration="1000"
+        android:valueFrom="#00ffffff"
+        android:valueTo="#161c2d"
+        android:valueType="colorType"
+        android:interpolator="@android:interpolator/fast_out_slow_in"/>
+    </aapt:attr>
+  </target>
+  <target android:name="path_1">
+    <aapt:attr name="android:animation">
+      <objectAnimator
+        android:propertyName="fillColor"
+        android:duration="1000"
+        android:valueFrom="#00ffffff"
+        android:valueTo="#f9f9fb"
+        android:valueType="colorType"
+        android:interpolator="@android:interpolator/fast_out_slow_in"/>
+    </aapt:attr>
+  </target>
+  <target android:name="path_2">
+    <aapt:attr name="android:animation">
+      <objectAnimator
+        android:propertyName="fillColor"
+        android:duration="1000"
+        android:valueFrom="#00ffffff"
+        android:valueTo="#f9f9fb"
+        android:valueType="colorType"
+        android:interpolator="@android:interpolator/fast_out_slow_in"/>
+    </aapt:attr>
+  </target>
+</animated-vector>

UI/AndroidUpdate/src/AndroidUpdate.Android/Resources/drawable-v31/avalonia_anim.xml

@@ -0,0 +1,71 @@
+<animated-vector
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt">
+    <aapt:attr name="android:drawable">
+        <vector
+            android:name="vector"
+            android:width="128dp"
+            android:height="128dp"
+            android:viewportWidth="128"
+            android:viewportHeight="128">
+            <group
+                android:name="wrapper"
+                android:translateX="21"
+                android:translateY="21">
+                <group android:name="group">
+                    <path
+                        android:name="path"
+                        android:pathData="M 74.853 85.823 L 75.368 85.823 C 80.735 85.823 85.144 81.803 85.761 76.602 L 85.836 41.76 C 85.225 18.593 66.254 0 42.939 0 C 19.24 0 0.028 19.212 0.028 42.912 C 0.028 66.357 18.831 85.418 42.18 85.823 L 74.853 85.823 Z"
+                        android:fillColor="#00ffffff"
+                        android:strokeWidth="1"/>
+                    <path
+                        android:name="path_1"
+                        android:pathData="M 43.059 14.614 C 29.551 14.614 18.256 24.082 15.445 36.743 C 18.136 37.498 20.109 39.968 20.109 42.899 C 20.109 45.831 18.136 48.301 15.445 49.055 C 18.256 61.716 29.551 71.184 43.059 71.184 C 47.975 71.184 52.599 69.93 56.628 67.723 L 56.628 70.993 L 71.344 70.993 L 71.344 44.072 C 71.357 43.714 71.344 43.26 71.344 42.899 C 71.344 27.278 58.68 14.614 43.059 14.614 Z M 29.51 42.899 C 29.51 35.416 35.576 29.35 43.059 29.35 C 50.541 29.35 56.607 35.416 56.607 42.899 C 56.607 50.382 50.541 56.448 43.059 56.448 C 35.576 56.448 29.51 50.382 29.51 42.899 Z"
+                        android:fillColor="#00ffffff"
+                        android:strokeWidth="1"
+                        android:fillType="evenOdd"/>
+                    <path
+                        android:name="path_2"
+                        android:pathData="M 18.105 42.88 C 18.105 45.38 16.078 47.407 13.579 47.407 C 11.079 47.407 9.052 45.38 9.052 42.88 C 9.052 40.381 11.079 38.354 13.579 38.354 C 16.078 38.354 18.105 40.381 18.105 42.88 Z"
+                        android:fillColor="#00ffffff"
+                        android:strokeWidth="1"/>
+                </group>
+            </group>
+        </vector>
+    </aapt:attr>
+    <target android:name="path_2">
+        <aapt:attr name="android:animation">
+            <objectAnimator
+                android:propertyName="fillColor"
+                android:startOffset="100"
+                android:duration="900"
+                android:valueFrom="#00ffffff"
+                android:valueTo="#161c2d"
+                android:valueType="colorType"
+                android:interpolator="@android:interpolator/fast_out_slow_in"/>
+        </aapt:attr>
+    </target>
+    <target android:name="path">
+        <aapt:attr name="android:animation">
+            <objectAnimator
+                android:propertyName="fillColor"
+                android:duration="500"
+                android:valueFrom="#00ffffff"
+                android:valueTo="#f9f9fb"
+                android:valueType="colorType"
+                android:interpolator="@android:interpolator/fast_out_slow_in"/>
+        </aapt:attr>
+    </target>
+    <target android:name="path_1">
+        <aapt:attr name="android:animation">
+            <objectAnimator
+                android:propertyName="fillColor"
+                android:startOffset="100"
+                android:duration="900"
+                android:valueFrom="#00ffffff"
+                android:valueTo="#161c2d"
+                android:valueType="colorType"
+                android:interpolator="@android:interpolator/fast_out_slow_in"/>
+        </aapt:attr>
+    </target>
+</animated-vector>

UI/AndroidUpdate/src/AndroidUpdate.Android/Resources/drawable/splash_screen.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+
+  <item>
+    <color android:color="@color/splash_background"/>
+  </item>
+
+  <item android:drawable="@drawable/icon"
+        android:width="120dp"
+        android:height="120dp"
+        android:gravity="center" />
+
+</layer-list>

UI/AndroidUpdate/src/AndroidUpdate.Android/Resources/values-night/colors.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+  <color name="splash_background">#212121</color>
+</resources>

UI/AndroidUpdate/src/AndroidUpdate.Android/Resources/values-v31/styles.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<resources>
+
+  <style name="MyTheme">
+  </style>
+
+  <style name="MyTheme.NoActionBar" parent="@style/Theme.AppCompat.NoActionBar">
+    <item name="android:windowActionBar">false</item>
+    <item name="android:windowBackground">@null</item>
+    <item name="android:windowNoTitle">true</item>
+    <item name="android:windowSplashScreenBackground">@color/splash_background</item>
+    <item name="android:windowSplashScreenAnimatedIcon">@drawable/avalonia_anim</item>
+    <item name="android:windowSplashScreenAnimationDuration">1000</item>
+    <item name="postSplashScreenTheme">@style/MyTheme.Main</item>
+
+  </style>
+  <style name="MyTheme.Main"
+         parent ="MyTheme.NoActionBar">
+    <item name="android:windowIsTranslucent">true</item>
+  </style>
+</resources>

UI/AndroidUpdate/src/AndroidUpdate.Android/Resources/values/colors.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+  <color name="splash_background">#FFFFFF</color>
+</resources>

UI/AndroidUpdate/src/AndroidUpdate.Android/Resources/values/styles.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<resources>
+
+  <style name="MyTheme">
+  </style>
+
+  <style name="MyTheme.NoActionBar" parent="@style/Theme.AppCompat.DayNight.NoActionBar">
+    <item name="android:windowActionBar">false</item>
+    <item name="android:windowBackground">@drawable/splash_screen</item>
+    <item name="android:windowNoTitle">true</item>
+  </style>
+</resources>