DotNet Core .csproj code files as child items

Question

I am migrating an old .NET Framework csproj to dotnet core. What is the dotnet core equivalent of this:

<Compile Include="ServiceHost.Designer.cs">
  <DependentUpon>ServiceHost.cs</DependentUpon>
</Compile>

I tried:

<ItemGroup>
    <Compile Include="ServiceHost.Designer.cs">
        <DependentUpon>ServiceHost.cs</DependentUpon>
    </Compile>
</ItemGroup>

But I got this error:

Duplicate 'Compile' items were included. The .NET SDK includes 'Compile' items from your project directory by default. You can either remove these items from your project file, or set the 'EnableDefaultCompileItems' property to 'false' if you want to explicitly include them in your project file. For more information, see https://aka.ms/sdkimplicititems. The duplicate items were: 'ProjectInstaller.Designer.cs'; 'ServiceHost.Designer.cs' TestWindowsService C:\Program Files\dotnet\sdk\2.1.4\Sdks\Microsoft.NET.Sdk\build\Microsoft.NET.Sdk.DefaultItems.targets

Answer 1

Since the items are included by default, you need to use Update instead of Include if you only want to modify the items that need this update and not list every cs file individually:

<ItemGroup>
    <Compile Update="ServiceHost.Designer.cs">
        <DependentUpon>ServiceHost.cs</DependentUpon>
    </Compile>
</ItemGroup>