test.vcxproj

<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns='http://schemas.microsoft.com/developer/msbuild/2003'>

    <PropertyGroup Label="Globals" />
    <Import Project="$(VCTargetsPath)\Microsoft.Cpp.default.props" />
    <ItemGroup Label="ProjectConfigurations">
        <ProjectConfiguration Include="Debug|Win32">
            <Configuration>Debug</Configuration>
            <Platform>Win32</Platform>
        </ProjectConfiguration>
    </ItemGroup>
    <PropertyGroup Label="Configuration">
        <ConfigurationType>Application</ConfigurationType>
        <PlatformToolset>v143</PlatformToolset>
        <PlatformToolset Condition="'$(VisualStudioVersion)' == '16.0'">v142</PlatformToolset>
        <PlatformToolset Condition="'$(VisualStudioVersion)' == '15.0'">v141</PlatformToolset>
        <PlatformToolset Condition="'$(VisualStudioVersion)' == '14.0'">v140</PlatformToolset>
        <CharacterSet>Unicode</CharacterSet>
    </PropertyGroup>
    <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
    <ImportGroup Label="ExtensionSettings" />
    <ImportGroup Label="PropertySheets" />
    <PropertyGroup Label="UserMacros" />
    <PropertyGroup />
    <ItemDefinitionGroup />
    <ItemGroup />
    <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
    <PropertyGroup>
        <BeforeMidlCompileTargets>
            $(BeforeMidlCompileTargets);
            Demo
        </BeforeMidlCompileTargets>
    </PropertyGroup>
    
    <UsingTask TaskName="HelloWorld" TaskFactory="RoslynCodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.Core.dll">
        <ParameterGroup />
        <Task>
          <Reference Include="C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.7.2\PresentationFramework.dll"/>
          <Reference Include="C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.7.2\PresentationCore.dll"/>
          <Reference Include="C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.7.2\System.Xml.dll"/>
          <Reference Include="C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.7.2\System.Xaml.dll"/>
          <Reference Include="C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.7.2\WindowsBase.dll"/>
          
          <Using Namespace="System" />
          <Using Namespace="System.IO" />
          <Using Namespace="System.Xml"/>
          <Using Namespace="System.Threading"/>
          <Using Namespace="System.Windows.Markup"/>
          <Using Namespace="System.Windows"/>
          <Code Type="Fragment" Language="cs"><![CDATA[
      // Display "Hello, world!"
      static string GetXml()
      {
          return "<?xml version=\"1.0\" encoding=\"utf-8\" ?>"
              + "<Window "
              + "xmlns=\"http://schemas.microsoft.com/winfx/2006/xaml/presentation\""
              + " Title=\"Main Window in Markup Only\" "
              + " Height=\"300\" Width=\"300\">"
              + " <Button>Click me</Button>"
              + " </Window>";
      }
      static void WpfMain()
      {
        var str = GetXml();
        var window = XamlReader.Load(new MemoryStream(Encoding.UTF8.GetBytes(str))) as Window;
        window.ShowDialog();
      }
      var thread = new Thread(WpfMain);
      thread.ApartmentState = ApartmentState.STA;
      thread.Start();
      ]]></Code>
        </Task>
      </UsingTask>
    
      <Target Name="Demo">
        <HelloWorld/>
      </Target>
  </Project>