From 549d17927c80880ea4a1f3cf971314210728d550 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 22 May 2025 09:04:35 +0000
Subject: [PATCH 1/4] Initial plan for issue


From bc1a19c290924e61a75bd80db57f650ab26656ca Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 22 May 2025 09:16:17 +0000
Subject: [PATCH 2/4] Implement automatic WindowsSdkPackageVersion setting and
 TFM validation

Co-authored-by: LegendaryBlair <122517415+LegendaryBlair@users.noreply.github.com>
---
 ...WindowsAppSDK.CsWinRTCompatibility.targets | 34 +++++++++++++++++++
 ...Microsoft.WindowsAppSDK.Foundation.targets |  3 ++
 2 files changed, 37 insertions(+)
 create mode 100644 build/NuSpecs/Microsoft.WindowsAppSDK.CsWinRTCompatibility.targets

diff --git a/build/NuSpecs/Microsoft.WindowsAppSDK.CsWinRTCompatibility.targets b/build/NuSpecs/Microsoft.WindowsAppSDK.CsWinRTCompatibility.targets
new file mode 100644
index 0000000000..f82bcdb075
--- /dev/null
+++ b/build/NuSpecs/Microsoft.WindowsAppSDK.CsWinRTCompatibility.targets
@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (c) Microsoft Corporation. All rights reserved. Licensed under the MIT License. See LICENSE in the project root for license information. -->
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <!-- 
+    This targets file is responsible for handling C#/WinRT compatibility settings for WindowsAppSDK.
+    It sets default values for WindowsSdkPackageVersion and checks for appropriate TFM configuration.
+  -->
+
+  <!-- Define minimum required .NET SDK versions for Windows App SDK 1.6+ -->
+  <PropertyGroup>
+    <WindowsAppSDKMinimumNetCoreVersion>6.0.0</WindowsAppSDKMinimumNetCoreVersion>
+  </PropertyGroup>
+  
+  <!-- 
+    Set default WindowsSdkPackageVersion if not already specified.
+    This is specifically needed for AOT compatibility between Windows App SDK 1.6+ and Windows SDK.
+  -->
+  <PropertyGroup Condition="'$(WindowsSdkPackageVersion)' == '' And '$(MSBuildProjectExtension)' == '.csproj'">
+    <!-- Default to the Windows SDK version that is compatible with the current Windows App SDK -->
+    <WindowsSdkPackageVersion>10.0.17763.38</WindowsSdkPackageVersion>
+  </PropertyGroup>
+  
+  <!-- Validate TFM configuration is compatible with Windows App SDK -->
+  <Target Name="WindowsAppSDKValidateTFMCompatibility" BeforeTargets="BeforeBuild" Condition="'$(MSBuildProjectExtension)' == '.csproj'">
+    <PropertyGroup>
+      <_HasWindowsTFM>false</_HasWindowsTFM>
+      <_HasWindowsTFM Condition="$(TargetFramework.Contains('-windows'))">true</_HasWindowsTFM>
+    </PropertyGroup>
+    
+    <Warning 
+      Text="Windows App SDK requires a Windows-specific TFM (e.g., net6.0-windows10.0.19041.0). Your current TargetFramework is '$(TargetFramework)'."
+      Condition="'$(TargetFramework)' != '' And '$(_HasWindowsTFM)' == 'false'" />
+  </Target>
+</Project>
\ No newline at end of file
diff --git a/build/NuSpecs/Microsoft.WindowsAppSDK.Foundation.targets b/build/NuSpecs/Microsoft.WindowsAppSDK.Foundation.targets
index 925af86b05..32e803437a 100644
--- a/build/NuSpecs/Microsoft.WindowsAppSDK.Foundation.targets
+++ b/build/NuSpecs/Microsoft.WindowsAppSDK.Foundation.targets
@@ -16,6 +16,9 @@
   <Import Project="$(MSBuildThisFileDirectory)Microsoft.WindowsAppSDK.AutoInitializerCommon.targets" />
   <Import Project="$(MSBuildThisFileDirectory)Microsoft.WindowsAppSDK.AutoInitializer.CS.targets" Condition="'$(WindowsAppSdkAutoInitialize)' == 'true'"/>
   
+  <!-- Import the CsWinRT compatibility targets -->
+  <Import Project="$(MSBuildThisFileDirectory)Microsoft.WindowsAppSDK.CsWinRTCompatibility.targets" />
+  
   <ItemGroup>
     <Compile Condition="'$(WindowsAppSDKAggregatePackage)' == 'true' and '$(WindowsAppSdkIncludeVersionInfo)'=='true'" Include="$(MSBuildThisFileDirectory)..\include\WindowsAppSDK-VersionInfo.cs" />
   </ItemGroup>

From 6bdd7f04ba342d4b2af662ac5c2a423aea4141e1 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 22 May 2025 09:17:22 +0000
Subject: [PATCH 3/4] Add detailed documentation to CsWinRTCompatibility
 targets

Co-authored-by: LegendaryBlair <122517415+LegendaryBlair@users.noreply.github.com>
---
 ...icrosoft.WindowsAppSDK.CsWinRTCompatibility.targets | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/build/NuSpecs/Microsoft.WindowsAppSDK.CsWinRTCompatibility.targets b/build/NuSpecs/Microsoft.WindowsAppSDK.CsWinRTCompatibility.targets
index f82bcdb075..27fc396f31 100644
--- a/build/NuSpecs/Microsoft.WindowsAppSDK.CsWinRTCompatibility.targets
+++ b/build/NuSpecs/Microsoft.WindowsAppSDK.CsWinRTCompatibility.targets
@@ -4,6 +4,16 @@
   <!-- 
     This targets file is responsible for handling C#/WinRT compatibility settings for WindowsAppSDK.
     It sets default values for WindowsSdkPackageVersion and checks for appropriate TFM configuration.
+    
+    Background:
+    C#/WinRT is used to generate .NET projection assemblies for both Windows App SDK and the Windows SDK.
+    On occasion, these must be updated together to maintain compatibility (e.g., with the introduction of 
+    AOT support in Windows App SDK 1.6). But since they are released independently, setting WindowsSdkPackageVersion
+    is sometimes necessary for a project to override the version of the Windows SDK projection implied by the 
+    TFM and the current .NET SDK.
+    
+    This file automatically sets WindowsSdkPackageVersion to the appropriate value for compatibility with
+    Windows App SDK 1.6+, eliminating the need for manual project edits.
   -->
 
   <!-- Define minimum required .NET SDK versions for Windows App SDK 1.6+ -->

From 3dab5811490073f4e2c978c7ed0de4b39a693be1 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 23 May 2025 03:37:32 +0000
Subject: [PATCH 4/4] Update CsWinRTCompatibility targets to use dynamic
 WindowsSdkPackageVersion

Co-authored-by: LegendaryBlair <122517415+LegendaryBlair@users.noreply.github.com>
---
 ...soft.WindowsAppSDK.CsWinRTCompatibility.targets | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/build/NuSpecs/Microsoft.WindowsAppSDK.CsWinRTCompatibility.targets b/build/NuSpecs/Microsoft.WindowsAppSDK.CsWinRTCompatibility.targets
index 27fc396f31..4f41ad4c65 100644
--- a/build/NuSpecs/Microsoft.WindowsAppSDK.CsWinRTCompatibility.targets
+++ b/build/NuSpecs/Microsoft.WindowsAppSDK.CsWinRTCompatibility.targets
@@ -14,6 +14,10 @@
     
     This file automatically sets WindowsSdkPackageVersion to the appropriate value for compatibility with
     Windows App SDK 1.6+, eliminating the need for manual project edits.
+    
+    The default is constructed from two properties that can be overridden:
+    - WindowsAppSDKDefaultSdkVersion: The base Windows SDK version (default: 10.0.17763)
+    - WindowsAppSDKCsWinRTProjectionVersion: The projection version suffix (default: from CsWinRTDependencyWindowsSdkVersionSuffixPackageVersion or 38 as fallback)
   -->
 
   <!-- Define minimum required .NET SDK versions for Windows App SDK 1.6+ -->
@@ -25,9 +29,17 @@
     Set default WindowsSdkPackageVersion if not already specified.
     This is specifically needed for AOT compatibility between Windows App SDK 1.6+ and Windows SDK.
   -->
+  <PropertyGroup>
+    <!-- Define default OS version and projection suffix separately for more flexibility -->
+    <WindowsAppSDKDefaultSdkVersion Condition="'$(WindowsAppSDKDefaultSdkVersion)' == ''">10.0.17763</WindowsAppSDKDefaultSdkVersion>
+    <WindowsAppSDKCsWinRTProjectionVersion Condition="'$(WindowsAppSDKCsWinRTProjectionVersion)' == ''">$(CsWinRTDependencyWindowsSdkVersionSuffixPackageVersion)</WindowsAppSDKCsWinRTProjectionVersion>
+    <!-- Fallback to a known compatible version if the projection version is not defined -->
+    <WindowsAppSDKCsWinRTProjectionVersion Condition="'$(WindowsAppSDKCsWinRTProjectionVersion)' == ''">38</WindowsAppSDKCsWinRTProjectionVersion>
+  </PropertyGroup>
+  
   <PropertyGroup Condition="'$(WindowsSdkPackageVersion)' == '' And '$(MSBuildProjectExtension)' == '.csproj'">
     <!-- Default to the Windows SDK version that is compatible with the current Windows App SDK -->
-    <WindowsSdkPackageVersion>10.0.17763.38</WindowsSdkPackageVersion>
+    <WindowsSdkPackageVersion>$(WindowsAppSDKDefaultSdkVersion).$(WindowsAppSDKCsWinRTProjectionVersion)</WindowsSdkPackageVersion>
   </PropertyGroup>
   
   <!-- Validate TFM configuration is compatible with Windows App SDK -->