Add MAUI build queue to serialize platform builds

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

@@ -68,10 +68,10 @@
 	</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" />
+		<PackageReference Include="Microsoft.Maui.Controls" Version="10.0.20" />
+		<PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="10.0.2" />
+		<PackageReference Include="System.Net.Http.Json" Version="10.0.2" />
+		<PackageReference Include="Microsoft.Extensions.Http" Version="10.0.2" />
 	</ItemGroup>
 
 	<ItemGroup>

playground/AspireWithMaui/AspireWithMaui.MauiClient/MauiProgram.cs

@@ -28,7 +28,9 @@ public static MauiApp CreateMauiApp()
 		builder.Services.AddHttpClient<IWeatherService, WeatherService>(client =>
 		{
 			// This will be resolved via service discovery when running with Aspire
-			client.BaseAddress = new Uri("https://webapi");
+			// Use https+http:// scheme to allow fallback to HTTP when HTTPS is not available
+			// (e.g., when running on Android emulator without dev tunnels)
+			client.BaseAddress = new Uri("https+http://webapi");
 		});
 
 #if DEBUG

src/Aspire.Hosting.Maui/Annotations/MauiBuildInfoAnnotation.cs

@@ -0,0 +1,32 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Aspire.Hosting.ApplicationModel;
+
+namespace Aspire.Hosting.Maui.Annotations;
+
+/// <summary>
+/// Annotation carrying the build parameters for a MAUI platform resource, used by
+/// <see cref="Aspire.Hosting.Maui.Lifecycle.MauiBuildQueueEventSubscriber"/> to run the Build target
+/// before DCP launches the Run target.
+/// </summary>
+internal sealed class MauiBuildInfoAnnotation(
+    string projectPath,
+    string workingDirectory,
+    string? targetFramework) : IResourceAnnotation
+{
+    /// <summary>
+    /// Gets the absolute path to the project file.
+    /// </summary>
+    public string ProjectPath { get; } = projectPath;
+
+    /// <summary>
+    /// Gets the working directory for the build process.
+    /// </summary>
+    public string WorkingDirectory { get; } = workingDirectory;
+
+    /// <summary>
+    /// Gets the target framework moniker (e.g., net10.0-android).
+    /// </summary>
+    public string? TargetFramework { get; } = targetFramework;
+}

src/Aspire.Hosting.Maui/Annotations/MauiBuildQueueAnnotation.cs

@@ -0,0 +1,50 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Collections.Concurrent;
+using Aspire.Hosting.ApplicationModel;
+
+namespace Aspire.Hosting.Maui.Annotations;
+
+/// <summary>
+/// Annotation added to <see cref="MauiProjectResource"/> to serialize builds across
+/// platform resources that share the same project.
+/// </summary>
+internal sealed class MauiBuildQueueAnnotation : IResourceAnnotation
+{
+    /// <summary>
+    /// Gets the semaphore used to serialize builds for this project.
+    /// </summary>
+    public SemaphoreSlim BuildSemaphore { get; } = new(1, 1);
+
+    /// <summary>
+    /// Per-resource CTS that allows the stop command to cancel a queued or building resource.
+    /// The key is the resource name.
+    /// </summary>
+    public ConcurrentDictionary<string, CancellationTokenSource> ResourceCancellations { get; } = new();
+
+    /// <summary>
+    /// Cancels a resource's queued or building state.
+    /// </summary>
+    /// <returns><c>true</c> if the resource was found and cancelled; <c>false</c> otherwise.</returns>
+    public bool CancelResource(string resourceName)
+    {
+        if (ResourceCancellations.TryRemove(resourceName, out var cts))
+        {
+            try
+            {
+                cts.Cancel();
+            }
+            catch (ObjectDisposedException)
+            {
+                // The CTS was disposed by the event handler's using block after the build
+                // completed naturally at the exact moment the user clicked stop.
+                return false;
+            }
+
+            return true;
+        }
+
+        return false;
+    }
+}

src/Aspire.Hosting.Maui/Aspire.Hosting.Maui.csproj

@@ -9,6 +9,7 @@
     <SuppressFinalPackageVersion>true</SuppressFinalPackageVersion>
     <PackageTags>aspire maui hosting</PackageTags>
     <PackageIconFullPath>$(SharedDir)Maui_265x.png</PackageIconFullPath>
+    <NoWarn>$(NoWarn);ASPIREMAUI001</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>