.NET Core 3.0 gRPC code

Client.cs

using Greet;
using Grpc.Core;

namespace ClientApp
{
    class Program
    {
        static async Task Main(string[] args)
        {
            var channel = new Channel("localhost:50051",
                                      ChannelCredentials.Insecure);
            var client = new GreeterService.GreeterServiceClient(channel);
            var greeting = await client.SayHello(new HelloRequest
                                                 {
                                                     Name = "Alice" 
                                                 });
            Console.WriteLine(greeting.Message);
            await channel.ShutdownAsync();
        }
    }
}

DummyServiceGrpc.cs

public partial class DummyService : ProtoDummyService.ProtoDummyServiceBase
{
    public override async Task GetDataStream(GetDataStreamRequest request, IServerStreamWriter<CompositeType> responseStream, ServerCallContext context)
    {
        foreach (var item in GetDataStreamImpl(request.Min, request.Max))
        {
            await responseStream.WriteAsync(item);
        }
    }
}

DummyServiceGrpc.impl.cs

public partial class DummyService     
{
    // Copied from ServiceContract implementation
    public IEnumerable<CompositeType> GetDataStreamImpl(int min, int max)
    {
        for (int i = min; i < max; i++)
        {
            yield return new CompositeType {IntValue = i, StringValue = i.ToString() };
        }
    }
}

DummyServiceWcf.cs

public class DummyService : IDummyService
{
    public IEnumerable<CompositeType> GetDataStream(int min, int max)
    {
        for (int i = min; i < max; i++)
        {
            yield return new CompositeType {IntValue = i, StringValue = i.ToString() };
        }
    }
}

greet.proto

syntax = "proto3";

package Greet;

// The greeting service definition.
service Greeter {
  // Sends a greeting
  rpc SayHello (HelloRequest) returns (HelloReply) {}
}

// The request message containing the user's name.
message HelloRequest {
  string name = 1;
}

// The response message containing the greetings.
message HelloReply {
  string message = 1;
}

GreeterService.cs

using Greet;
using Grpc.Core;

namespace GrpcDemo
{
    public class GreeterService : Greeter.GreeterBase
    {
        public override Task<HelloReply> SayHello(HelloRequest request,
                                                  ServerCallContext context)
        {
            return Task.FromResult(new HelloReply
            {
                Message = "Hello " + request.Name
            });
        }
    }
}

Startup.cs

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddGrpc();
    }

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

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