XAML files are not supported

Attached is a simple repro solution. WpfCps.zip

Issue 1: XAML files are treated as None, when they should be treated as Page with Generator=MSBuild:Compile and SubType=Designer metadata. Issue 2: Page items are not visible in the Solution Explorer Issue 3: xaml.cs files are not properly nested under the xaml file Issue 4: Compilation fails with: 1>C:\windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.WinFx.targets(419,45): error MSB4057: The target "CoreCompile" does not exist in the project.

[gulbanana]

more complete version of the workarounds i use these days - import this at the end of a csproj

<Project>  
  <!-- https://github.com/dotnet/sdk/issues/810 - the temporary project has the wrong file extension -->
  <PropertyGroup>
    <LanguageTargets>$(MSBuildToolsPath)\Microsoft.CSharp.targets</LanguageTargets>
    <StartWorkingDirectory Condition="'$(OutputType)' == 'WinExe'">bin/$(Configuration)/$(TargetFramework)</StartWorkingDirectory>
  </PropertyGroup>
  
  <!-- Page items aren't included by the SDK -->
  <ItemGroup>
    <Page Include="**\*.xaml" Exclude="@(ApplicationDefinition)" SubType="Designer" Generator="MSBuild:Compile" />
    <Compile Update="**\*.xaml.cs" SubType="Code" DependentUpon="%(Filename)" />
    <UpToDateCheckInput Include="**\*.xaml" />
  </ItemGroup>

  <!-- https://github.com/dotnet/project-system/issues/2488 - .g.cs files don't get built -->
  <Target Name="WorkaroundForXAMLIntellisenseBuildIssue" AfterTargets="_CheckCompileDesignTimePrerequisite">
    <PropertyGroup>
      <BuildingProject>false</BuildingProject>
    </PropertyGroup>
  </Target>
</Project>

[gulbanana]

here are some workarounds for now

issues 1 and 2: <Page Include="**\*.xaml" SubType="Designer" Generator="MSBuild:Compile" />

issue 3: <Compile Update="**\*.xaml.cs" SubType="Code" DependentUpon="%(Filename)" />

issue 4: <LanguageTargets>$(MSBuildToolsPath)\Microsoft.CSharp.targets</LanguageTargets>