XAML自动代码生成在编辑.csproj文件后无法正常工作

Question

My project was originally an old .NET Framework 4.5 project and I was trying to migrate to 4.6.1 and add a reference to a .NET Standard 2 library. So I edited the csproj file and replaced its contents with the following:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net461</TargetFramework>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Extended.Wpf.Toolkit" Version="3.4.0" />
    <PackageReference Include="FFME.Windows" Version="4.0.270" />
    <PackageReference Include="FontAwesome5" Version="1.0.7" />
    <PackageReference Include="SevenZipSharp.Net45" Version="1.0.19" />
    <PackageReference Include="WindowsAPICodePack" Version="1.1.0" />
  </ItemGroup>
  <ItemGroup>
  </ItemGroup>
  <ItemGroup>
    <Reference Include="PresentationCore" />
    <Reference Include="PresentationFramework" />
    <Reference Include="System.ComponentModel.DataAnnotations" />
    <Reference Include="System.Data.DataSetExtensions" />
    <Reference Include="System.Net" />
    <Reference Include="System.Windows" />
    <Reference Include="System.Windows.Forms" />
    <Reference Include="System.Windows.Presentation" />
    <Reference Include="WindowsBase" />
  </ItemGroup>

</Project>

I have used this method in the past to migrate non-WPF Windows-based projects to have new project structure and it works as long as WPF is not used; but wherever XAML is involved, the auto-generated partial classes are missing. How can I get this to work?

Answer 1

You lost some important properties and some important items in your csproj file.

If you target .NET Framework:

You should add a LanguageTargets property, and if you lost it WPF XAML files will not build.

Then copy the items below to include all your XAML files, resource files and setting files.

It's recommended to copy the code below to your csproj file and add your own other items.

<Project Sdk="Microsoft.NET.Sdk">
    <PropertyGroup>
        <TargetFramework>net47</TargetFramework>

        <!-- Important! You've lost it. -->
        <LanguageTargets>$(MSBuildToolsPath)\Microsoft.CSharp.targets</LanguageTargets>

        <!-- If this is not the main exe project, Remove it. -->
        <OutputType>WinExe</OutputType>

    </PropertyGroup>

    <ItemGroup>

        <!-- App.xaml -->
        <ApplicationDefinition Include="App.xaml" SubType="Designer" Generator="MSBuild:Compile" />

        <!-- XAML elements -->
        <Page Include="**\*.xaml" Exclude="App.xaml" SubType="Designer" Generator="MSBuild:Compile" />
        <Compile Update="**\*.xaml.cs" DependentUpon="%(Filename)" />

        <!-- Resources -->
        <EmbeddedResource Update="Properties\Resources.resx" Generator="ResXFileCodeGenerator" LastGenOutput="Resources.Designer.cs" />
        <Compile Update="Properties\Resources.Designer.cs" AutoGen="True" DependentUpon="Resources.resx" DesignTime="True" />

        <!-- Settings -->
        <None Update="Properties\Settings.settings" Generator="SettingsSingleFileGenerator" LastGenOutput="Settings.Designer.cs" />
        <Compile Update="Properties\Settings.Designer.cs" AutoGen="True" DependentUpon="Settings.settings" />

    </ItemGroup>

    <ItemGroup>
        <Reference Include="PresentationCore" />
        <Reference Include="PresentationFramework" />
        <Reference Include="System.Xaml" />
        <Reference Include="WindowsBase" />
    </ItemGroup>
</Project>

If you target WPF on .NET Core:

Your csproj file will be much simpler.

<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
    <PropertyGroup>

        <TargetFramework>netcoreapp3.0</TargetFramework>
        <UseWPF>true</UseWPF>

        <!-- If this is not the main exe project, Remove it. -->
        <OutputType>WinExe</OutputType>

    </PropertyGroup>
</Project>

Tips

You may want to add more application properties in your <PropertyGroup /> :

<PropertyGroup>

    <!-- If you have App.manifest, add this here. -->
    <!-- <ApplicationManifest>Properties\App.manifest</ApplicationManifest> -->

    <!-- f you have App.ico, add this here. -->
    <!-- <ApplicationIcon>Properties\App.ico</ApplicationIcon> -->

    <!-- If you have another startup object instead of App.xaml, change it to it. -->
    <StartupObject />

</PropertyGroup>

Posts

The csproj file content above are posted on my sites:

• 将 WPF、UWP 以及其他各种类型的旧 csproj 迁移成基于 Microsoft.NET.Sdk 的新 csproj - walterlv
• 将基于 .NET Framework 的 WPF 项目迁移到基于 .NET Core 3 - walterlv

Answer 2

The problem is with not including Page tags from the old .csproj file. This is how the new .csproj file looks like:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net461</TargetFramework>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Extended.Wpf.Toolkit" Version="3.4.0" />
    <PackageReference Include="FFME.Windows" Version="4.0.270" />
    <PackageReference Include="FontAwesome5" Version="1.0.7" />
    <PackageReference Include="SevenZipSharp.Net45" Version="1.0.19" />
    <PackageReference Include="WindowsAPICodePack" Version="1.1.0" />
  </ItemGroup>
  <ItemGroup>
  </ItemGroup>
  <ItemGroup>
    <Reference Include="PresentationCore" />
    <Reference Include="PresentationFramework" />
    <Reference Include="System.ComponentModel.DataAnnotations" />
    <Reference Include="System.Data.DataSetExtensions" />
    <Reference Include="System.Net" />
    <Reference Include="System.Windows" />
    <Reference Include="System.Windows.Forms" />
    <Reference Include="System.Windows.Presentation" />
    <Reference Include="WindowsBase" />
  </ItemGroup>

  <ItemGroup>
    <Page Include="MainWindow.xaml">
      <SubType>Designer</SubType>
      <Generator>MSBuild:Compile</Generator>
    </Page>
    ...
  </ItemGroup>

</Project>

Now it's working like a charm!