在.NET核心中使用GRPC自定义标头

<ItemGroup>
  <PackageReference Include="Grpc.AspNetCore" Version="2.40.0" />
</ItemGroup>

syntax = "proto3";

service MyService {
  rpc MyMethod (MyRequest) returns (MyResponse) {}
}

message MyRequest {
  string message = 1;
}

message MyResponse {
  string reply = 1;
}

protoc -I . my_service.proto --csharp_out . --grpc_out . --plugin=protoc-gen-grpc=/path/to/grpc_csharp_plugin

public class MyService : MyServiceBase
{
    public override Task<MyResponse> MyMethod(MyRequest request, ServerCallContext context)
    {
        var response = new MyResponse { Reply = "Hello " + request.Message };

        // 添加自定义标头
        var headers = new Metadata
        {
            { "Custom-Header", "Value" }
        };
        context.ResponseTrailersAsync(headers);

        return Task.FromResult(response);
    }
}

public void ConfigureServices(IServiceCollection services)
{
    services.AddGrpc(options =>
    {
        options.EnableDetailedErrors = true;
    });
}

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    // ...

    app.UseRouting();

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapGrpcService<MyService>();

        // ...
    });
}