MSBuild target file that handle Grpc.Tools generation, And example on how to include

Project.csproj

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
      <TargetFramework>netstandard2.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Google.Protobuf" Version="3.6.1" />
    <PackageReference Include="Grpc" Version="1.14.2" />
    <PackageReference Include="Grpc.Tools" Version="1.14.2" />
  </ItemGroup>

  <Import Project="proto.targets" />

</Project>

Proto.targets

<?xml version="1.0" encoding="utf-8" ?>
<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
    <Target Name="BuildProto" BeforeTargets="Compile;BeforeBuild">
        <XmlPeek XmlInputPath="$(MSBuildProjectFullPath)"
                 Query="//PackageReference[@Include='Grpc.Tools']/@Version" >
            <Output TaskParameter="Result" ItemName="GrpcToolsVersion" />
        </XmlPeek>

        <PropertyGroup>
            <GrpcTools>$(NuGetPackageRoot)\grpc.tools\@(GrpcToolsVersion)\tools\windows_x64</GrpcTools>
            <GrpcPlugin>protoc-gen-grpc=$(GrpcTools)\grpc_csharp_plugin.exe</GrpcPlugin>
        </PropertyGroup>

        <ItemGroup>
            <ProtoFiles Include="*.proto" />
            <ProtoOutput Include="Proto\*.cs" />
        </ItemGroup>

        <MakeDir Directories="Proto" />
        <Delete Files="@(ProtoOutput)" />

        <ItemGroup>
            <Args Include="--csharp_out $(MSBuildProjectDirectory)\Proto" />
            <Args Include="--grpc_out $(MSBuildProjectDirectory)\Proto --plugin=$(GrpcPlugin)" />
        </ItemGroup>

        <Exec Command="$(GrpcTools)\protoc.exe @(Args, ' ') %(ProtoFiles.Identity)" ConsoleToMSBuild="true"></Exec>
    </Target>
</Project>