Add Aspire.Hosting.Maui (.NET MAUI) integration

.github/CODEOWNERS

@@ -6,10 +6,12 @@
 /src/Aspire.Hosting.Azure.AppContainers  @captainsafia @eerhardt
 /src/Aspire.Hosting.Azure.AppService  @captainsafia @eerhardt
 /src/Aspire.Hosting.Docker            @captainsafia
+/src/Aspire.Hosting.Maui              @jfversluis
 
 # tests
 
 /tests/Aspire.EndToEnd.Tests          @radical @eerhardt
+/tests/Aspire.Hosting.Maui.Tests      @jfversluis
 /tests/Aspire.Hosting.Testing.Tests   @reubenbond
 /tests/Aspire.Hosting.Tests           @mitchdenny
 /tests/Aspire.Templates.Tests          @radical @eerhardt
@@ -20,3 +22,4 @@
 # playground apps
 /playground/deployers                @captainsafia
 /playground/publishers               @captainsafia
+/playground/AspireWithMaui           @jfversluis

eng/Build.props

@@ -28,7 +28,9 @@
     <ProjectToBuild Include="$(RepoRoot)eng\dcppack\**\*.csproj" />
     <ProjectToBuild Include="$(RepoRoot)eng\dashboardpack\**\*.csproj" />
 
-    <ProjectToBuild Include="$(RepoRoot)playground\**\*.csproj" />
+    <!-- Exclude only the MAUI client project as it requires the .NET MAUI workload.
+         Other projects in the AspireWithMaui playground can still be built. -->
+    <ProjectToBuild Include="$(RepoRoot)playground\**\*.csproj" Exclude="$(RepoRoot)playground\AspireWithMaui\AspireWithMaui.MauiClient\*.csproj" />
   </ItemGroup>
 
   <!-- `$(SkipTestProjects)` allows skipping test projects from being

playground/AspireWithMaui/AspireWithMaui.AppHost/AppHost.cs

@@ -0,0 +1,17 @@
+var builder = DistributedApplication.CreateBuilder(args);
+
+var weatherApi = builder.AddProject("webapi", @"../AspireWithMaui.WeatherApi/AspireWithMaui.WeatherApi.csproj");
+
+var publicDevTunnel = builder.AddDevTunnel("devtunnel-public")
+    .WithAnonymousAccess() // All ports on this tunnel default to allowing anonymous access
+    .WithReference(weatherApi.GetEndpoint("https"));
+
+builder.AddMauiProject("mauiclient", @"../AspireWithMaui.MauiClient/AspireWithMaui.MauiClient.csproj")
+    .WithWindows()
+    .WithAndroid()
+    .WithiOS()
+    .WithMacCatalyst()
+    .WithOtlpDevTunnel() // Setup a tunnel for the Open Telemetry communication, only needed for Android & iOS, but also works for desktop
+    .WithReference(weatherApi, publicDevTunnel);
+
+builder.Build().Run();

playground/AspireWithMaui/AspireWithMaui.AppHost/AspireWithMaui.AppHost.csproj

@@ -0,0 +1,19 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>$(DefaultTargetFramework)</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <IsAspireHost>true</IsAspireHost>
+    <UserSecretsId>c086a0d6-b7a6-1337-a6a3-b62aa4616d88</UserSecretsId>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <AspireProjectOrPackageReference Include="Aspire.Hosting" />
+    <AspireProjectOrPackageReference Include="Aspire.Hosting.AppHost" />
+    <AspireProjectOrPackageReference Include="Aspire.Hosting.Maui" />
+    <AspireProjectOrPackageReference Include="Aspire.Hosting.DevTunnels" />
+  </ItemGroup>
+
+</Project>

playground/AspireWithMaui/AspireWithMaui.AppHost/Properties/launchSettings.json

@@ -0,0 +1,29 @@
+{
+  "$schema": "https://json.schemastore.org/launchsettings.json",
+  "profiles": {
+    "https": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "applicationUrl": "https://localhost:17279;http://localhost:15173",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development",
+        "DOTNET_ENVIRONMENT": "Development",
+        "ASPIRE_DASHBOARD_OTLP_ENDPOINT_URL": "https://localhost:21046",
+        "ASPIRE_RESOURCE_SERVICE_ENDPOINT_URL": "https://localhost:22093"
+      }
+    },
+    "http": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "applicationUrl": "http://localhost:15173",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development",
+        "DOTNET_ENVIRONMENT": "Development",
+        "ASPIRE_DASHBOARD_OTLP_ENDPOINT_URL": "http://localhost:19172",
+        "ASPIRE_RESOURCE_SERVICE_ENDPOINT_URL": "http://localhost:20091"
+      }
+    }
+  }
+}

playground/AspireWithMaui/AspireWithMaui.AppHost/appsettings.Development.json

@@ -0,0 +1,8 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}

playground/AspireWithMaui/AspireWithMaui.AppHost/appsettings.json

@@ -0,0 +1,9 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning",
+      "Aspire.Hosting.Dcp": "Warning"
+    }
+  }
+}

playground/AspireWithMaui/AspireWithMaui.MauiClient/App.xaml

@@ -0,0 +1,14 @@
+<?xml version = "1.0" encoding = "UTF-8" ?>
+<Application xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             xmlns:local="clr-namespace:AspireWithMaui.MauiClient"
+             x:Class="AspireWithMaui.MauiClient.App">
+    <Application.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <ResourceDictionary Source="Resources/Styles/Colors.xaml" />
+                <ResourceDictionary Source="Resources/Styles/Styles.xaml" />
+            </ResourceDictionary.MergedDictionaries>
+        </ResourceDictionary>
+    </Application.Resources>
+</Application>

playground/AspireWithMaui/AspireWithMaui.MauiClient/App.xaml.cs

@@ -0,0 +1,14 @@
+namespace AspireWithMaui.MauiClient;
+
+public partial class App : Application
+{
+	public App()
+	{
+		InitializeComponent();
+	}
+
+	protected override Window CreateWindow(IActivationState? activationState)
+	{
+		return new Window(new AppShell());
+	}
+}

playground/AspireWithMaui/AspireWithMaui.MauiClient/AppShell.xaml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<Shell
+    x:Class="AspireWithMaui.MauiClient.AppShell"
+    xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+    xmlns:local="clr-namespace:AspireWithMaui.MauiClient"
+    Title="AspireWithMaui.MauiClient">
+
+    <TabBar>
+        <Tab Title="Weather" Icon="weather.png">
+            <ShellContent
+                Title="Weather"
+                ContentTemplate="{DataTemplate local:MainPage}"
+                Route="weather" />
+        </Tab>
+        <Tab Title="Environment" Icon="aspire_outline.png">
+            <ShellContent
+                Title="Environment"
+                ContentTemplate="{DataTemplate local:EnvironmentPage}"
+                Route="environment" />
+        </Tab>
+    </TabBar>
+
+</Shell>

playground/AspireWithMaui/AspireWithMaui.MauiClient/AppShell.xaml.cs

@@ -0,0 +1,9 @@
+namespace AspireWithMaui.MauiClient;
+
+public partial class AppShell : Shell
+{
+	public AppShell()
+	{
+		InitializeComponent();
+	}
+}

playground/AspireWithMaui/AspireWithMaui.MauiClient/AspireWithMaui.MauiClient.csproj

@@ -0,0 +1,81 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+	<PropertyGroup>
+		<TargetFrameworks>net10.0-android;net10.0-ios;net10.0-maccatalyst</TargetFrameworks>
+		<TargetFrameworks Condition="$([MSBuild]::IsOSPlatform('windows'))">$(TargetFrameworks);net10.0-windows10.0.19041.0</TargetFrameworks>
+
+		<!-- Note for MacCatalyst:
+		The default runtime is maccatalyst-x64, except in Release config, in which case the default is maccatalyst-x64;maccatalyst-arm64.
+		When specifying both architectures, use the plural <RuntimeIdentifiers> instead of the singular <RuntimeIdentifier>.
+		The Mac App Store will NOT accept apps with ONLY maccatalyst-arm64 indicated;
+		either BOTH runtimes must be indicated or ONLY macatalyst-x64. -->
+		<!-- For example: <RuntimeIdentifiers>maccatalyst-x64;maccatalyst-arm64</RuntimeIdentifiers> -->
+
+		<OutputType>Exe</OutputType>
+		<RootNamespace>AspireWithMaui.MauiClient</RootNamespace>
+		<UseMaui>true</UseMaui>
+		<SingleProject>true</SingleProject>
+		<ImplicitUsings>enable</ImplicitUsings>
+		<Nullable>enable</Nullable>
+
+		<!-- Disable CPM for this MAUI project -->
+		<ManagePackageVersionsCentrally>false</ManagePackageVersionsCentrally>
+
+		<!-- Disable strong name checking for playground sample -->
+		<NoWarn>$(NoWarn);CS8002</NoWarn>
+
+		<!-- Ignore unnecessary using directive warnings -->
+		<NoWarn>$(NoWarn);IDE0005</NoWarn>
+
+		<!-- Display name -->
+		<ApplicationTitle>AspireWithMaui.MauiClient</ApplicationTitle>
+
+		<!-- App Identifier -->
+		<ApplicationId>com.companyname.aspirewithmaui.mauiclient</ApplicationId>
+
+		<!-- Versions -->
+		<ApplicationDisplayVersion>1.0</ApplicationDisplayVersion>
+		<ApplicationVersion>1</ApplicationVersion>
+
+		<!-- To develop, package, and publish an app to the Microsoft Store, see: https://aka.ms/MauiTemplateUnpackaged -->
+		<WindowsPackageType>None</WindowsPackageType>
+
+		<SupportedOSPlatformVersion Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'ios'">15.0</SupportedOSPlatformVersion>
+		<SupportedOSPlatformVersion Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'maccatalyst'">15.0</SupportedOSPlatformVersion>
+		<SupportedOSPlatformVersion Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'android'">21.0</SupportedOSPlatformVersion>
+		<SupportedOSPlatformVersion Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'windows'">10.0.17763.0</SupportedOSPlatformVersion>
+		<TargetPlatformMinVersion Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'windows'">10.0.17763.0</TargetPlatformMinVersion>
+	</PropertyGroup>
+
+	<ItemGroup>
+		<!-- App Icon -->
+		<MauiIcon Include="Resources\AppIcon\appicon.svg" ForegroundFile="Resources\AppIcon\appiconfg.svg" Color="#512BD4" />
+
+		<!-- Splash Screen -->
+		<MauiSplashScreen Include="Resources\Splash\splash.svg" Color="#512BD4" BaseSize="128,128" />
+
+		<!-- Images -->
+		<MauiImage Include="Resources\Images\*" />
+		<MauiImage Update="Resources\Images\dotnet_bot.png" Resize="True" BaseSize="680,628" />
+		<MauiImage Update="Resources\Images\aspire_outline.svg" Resize="True" BaseSize="256,256" />
+		<MauiImage Update="Resources\Images\weather.png" Resize="True" BaseSize="512,512" />
+
+		<!-- Custom Fonts -->
+		<MauiFont Include="Resources\Fonts\*" />
+
+		<!-- Raw Assets (also remove the "Resources\Raw" prefix) -->
+		<MauiAsset Include="Resources\Raw\**" LogicalName="%(RecursiveDir)%(Filename)%(Extension)" />
+	</ItemGroup>
+
+	<ItemGroup>
+		<PackageReference Include="Microsoft.Maui.Controls" Version="10.0.0-rc.1.25452.6" />
+		<PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="10.0.0-rc.2.25465.106" />
+		<PackageReference Include="System.Net.Http.Json" Version="10.0.0-rc.2.25465.106" />
+		<PackageReference Include="Microsoft.Extensions.Http" Version="10.0.0-rc.2.25465.106" />
+	</ItemGroup>
+
+	<ItemGroup>
+		<ProjectReference Include="..\AspireWithMaui.MauiServiceDefaults\AspireWithMaui.MauiServiceDefaults.csproj" />
+	</ItemGroup>
+
+</Project>

playground/AspireWithMaui/AspireWithMaui.MauiClient/EnvironmentPage.xaml

@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="AspireWithMaui.MauiClient.EnvironmentPage"
+             Title="Environment">
+
+    <Grid Padding="24,20"
+          RowSpacing="18"
+          RowDefinitions="Auto,*">
+        <VerticalStackLayout Spacing="12">
+            <Label Text="Aspire Environment Variables"
+                   Style="{StaticResource Headline}"
+                   SemanticProperties.HeadingLevel="Level1" />
+
+            <Label Text="These values are forwarded from the AppHost to the MAUI client so the app can connect to services and discovery endpoints."
+                   Style="{StaticResource Body}"
+                   LineBreakMode="WordWrap" />
+        </VerticalStackLayout>
+
+        <CollectionView Grid.Row="1"
+                        ItemsSource="{Binding AspireEnvironmentVariables}"
+                        BackgroundColor="Transparent"
+                        EmptyView="No Aspire-specific environment variables found.">
+            <CollectionView.ItemTemplate>
+                <DataTemplate>
+                    <Frame HasShadow="False"
+                           Padding="14"
+                           Margin="0,0,0,12"
+                           BackgroundColor="{AppThemeBinding Light=#F0F0F0, Dark=#1F1F1F}">
+                        <VerticalStackLayout Spacing="6">
+                            <Label Text="{Binding Key}"
+                                   FontAttributes="Bold"
+                                   LineBreakMode="CharacterWrap" />
+                            <Label Text="{Binding Value}"
+                                   FontSize="12"
+                                   LineBreakMode="WordWrap" />
+                        </VerticalStackLayout>
+                    </Frame>
+                </DataTemplate>
+            </CollectionView.ItemTemplate>
+        </CollectionView>
+    </Grid>
+
+</ContentPage>

playground/AspireWithMaui/AspireWithMaui.MauiClient/EnvironmentPage.xaml.cs

@@ -0,0 +1,79 @@
+using System.Collections;
+using System.Collections.ObjectModel;
+
+namespace AspireWithMaui.MauiClient;
+
+public partial class EnvironmentPage : ContentPage
+{
+    public ObservableCollection<KeyValuePair<string, string>> AspireEnvironmentVariables { get; } = new();
+
+    public EnvironmentPage()
+    {
+        InitializeComponent();
+        BindingContext = this;
+    }
+
+    protected override void OnAppearing()
+    {
+        base.OnAppearing();
+        LoadAspireEnvironmentVariables();
+    }
+
+    private void LoadAspireEnvironmentVariables()
+    {
+        AspireEnvironmentVariables.Clear();
+
+        var variables = Environment.GetEnvironmentVariables()
+            .Cast<DictionaryEntry>()
+            .Select(entry => new KeyValuePair<string, string>(entry.Key?.ToString() ?? string.Empty, DecodeValue(entry.Value?.ToString())))
+            .Where(item => IsAspireVariable(item.Key))
+            .OrderBy(item => item.Key, StringComparer.OrdinalIgnoreCase);
+
+        foreach (var variable in variables)
+        {
+            AspireEnvironmentVariables.Add(variable);
+        }
+    }
+
+    private static string DecodeValue(string? value)
+    {
+        if (string.IsNullOrEmpty(value))
+        {
+            return string.Empty;
+        }
+
+        try
+        {
+            var decoded = Uri.UnescapeDataString(value);
+
+            // Validate that the decoded string doesn't contain control characters that could indicate malicious content
+            // Allow only printable characters, tabs, and newlines
+            if (decoded.Any(c => char.IsControl(c) && c != '\t' && c != '\n' && c != '\r'))
+            {
+                // If suspicious control characters found, return the original encoded value for safety
+                return value;
+            }
+
+            return decoded;
+        }
+        catch (UriFormatException)
+        {
+            // If decoding fails, return the original value
+            return value;
+        }
+    }
+
+    private static bool IsAspireVariable(string key)
+        => key.StartsWith("services__", StringComparison.OrdinalIgnoreCase)
+           || key.StartsWith("connectionstrings__", StringComparison.OrdinalIgnoreCase)
+           || key.StartsWith("ASPIRE_", StringComparison.OrdinalIgnoreCase)
+           || key.StartsWith("AppHost__", StringComparison.OrdinalIgnoreCase)
+           || key.StartsWith("OTEL_", StringComparison.OrdinalIgnoreCase)
+           || key.StartsWith("LOGGING__CONSOLE", StringComparison.OrdinalIgnoreCase)
+           || key.Equals("ASPNETCORE_ENVIRONMENT", StringComparison.OrdinalIgnoreCase)
+           || key.Equals("ASPNETCORE_URLS", StringComparison.OrdinalIgnoreCase)
+           || key.Equals("DOTNET_ENVIRONMENT", StringComparison.OrdinalIgnoreCase)
+           || key.Equals("DOTNET_URLS", StringComparison.OrdinalIgnoreCase)
+           || key.Equals("DOTNET_LAUNCH_PROFILE", StringComparison.OrdinalIgnoreCase)
+           || key.Equals("DOTNET_SYSTEM_CONSOLE_ALLOW_ANSI_COLOR_REDIRECTION", StringComparison.OrdinalIgnoreCase);
+}