how to remove auto generated proto files from generated folder

Question

I have the below MSBuild to generate .cs files from my proto files. The build works fine until I do a rebuild where it complains of Source file 'generated-proto-output/Trade.cs# specified multiple times.

How do I delete my .cs files before building/rebuilding everytime?

Error

Severity Code Description Project File Line Suppression State Warning CS2002 Source file 'generated-proto-output\\ErrorTrade.cs' specified multiple times MyComp.Trade.Model C:\\dev\\workspaces\\trade-model-workspace\\model\\csharp\\MyComp.Trade.Model

build snippet in csproj file

    <ItemGroup>
        <Protobuf Remove="%(RelativePath)generated-proto-output/**/*.cs" />
        <Protobuf Include="../../proto/**/*.proto" ProtoRoot="../../proto/" OutputDir="%(RelativePath)generated-proto-output/" GrpcServices="None" />
        <Protobuf Update="../../proto/**/*Service.proto" GrpcServices="Both" />
      </ItemGroup>

UPDATE - Complete CSProj file (as requested by Lance)

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

  <PropertyGroup>
    <PackageId>TradeStore.Model</PackageId>
    <ProtoIncludes>.;../../proto</ProtoIncludes>
    <OutputType>Library</OutputType>
    <TargetFramework>netstandard2.0</TargetFramework>
    <Protobuf_NoWarnMissingExpected>true</Protobuf_NoWarnMissingExpected>
  </PropertyGroup>  

  <ItemGroup>
    <PackageReference Include="Google.Protobuf" Version="3.6.1" />    
    <PackageReference Include="Grpc" Version="1.19.0" />
    <PackageReference Include="Grpc.Tools" Version="1.19.0" PrivateAssets="All" />
  </ItemGroup>

  <ItemGroup>
    <FilesToDelete Include="%(RelativePath)generated-proto-output/*.cs" />
  </ItemGroup>

  <Target Name="DeleteSpecificFiles" BeforeTargets="Build">    
    <Message Text="Specific Files: @(FilesToDelete)"/>
    <Message Text ="Beginning to delete specific files before build or rebuild..."/>
    <Delete Files="@(FilesToDelete)"/>
  </Target>

    <ItemGroup>    
      <Protobuf Include="../../proto/**/*.proto" ProtoRoot="../../proto/" OutputDir="%(RelativePath)generated-proto-output/" GrpcServices="None" />
      <Protobuf Update="../../proto/**/*Service.proto" GrpcServices="Both" />
    </ItemGroup>

</Project>

Answer 1

How do I delete my .cs files before building/rebuilding everytime?

Try the following script with BeforeTargets below:

<Project...>
...
  <ItemGroup>
    <FilesToDelete Include="MyPath/*.cs" />
  </ItemGroup>
  <Target Name="DeleteSpecificFiles" BeforeTargets="build">
    <Message Text="Specific Files: @(FilesToDelete)"/>
    <Message Text ="Beginning to delete specific files before build or rebuild..."/>
    <Delete Files="@(FilesToDelete)"/>
  </Target>
</Project>

In addition:

Not seeing the whole content of your .csproj, so I can't figure out why the build snippet you use can't work. But a message task may help output some message whether the engine finds the files by your given path.

In visual studio, if you go Tools=>Options=>Project and Solutions=>Build and Run to change the build out verbosity to Detailed , you will see detailed output message after every build and rebuild. Ctrl+F and type the Target name you will find the details about delete process:

Hope it makes some help for your trouble-shooting.

Answer 2

Try adding CompileOutputs="false" to the directive. This will suppress the warning and won't require you to delete files before building csharp protobuf build integration