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.netcore grpc双向流方法详解

news 2025/8/12 20:06:14

一、双向流处理概述

简单来讲客户端可以向服务端发送消息流，服务端也可以向客户端传输响应流，即客户端和服务端可以互相通讯
客户端无需发送消息即可开始双向流式处理调用。客户端可选择使用 RequestStream.WriteAsync 发送消息。使用 ResponseStream.MoveNext() 或 ResponseStream.ReadAllAsync() 可访问从服务流式处理的消息。ResponseStream 没有更多消息时，双向流式处理调用完成。

二、案例简介

客户端发送请求流通过equestStream.WriteAsync传入到服务端
服务端响应到客户端的流通过ResponseStream.WriteAsync写入到客户端
服务端使用System.Threading.Channels保证线程安全交互

三、服务端配置（注意：grpc相关配置参考我之前的文章）

配置.proto文件

// 1.提供公共的实体proto文件
// 2.服务引用对应的proto文件
// 3.定义三个客户流方法//定义messages.proto文件令需要注意项目文件中的特性GrpcServices=None；syntax = "proto3";option csharp_namespace = "GrpcProject";package grpc.serviceing;// 消息推送/接收实体
message ExampleMessage
{string msg = 1;
}// 双向流文件twowaystream.protosyntax = "proto3";import "Protos/messages.proto";option csharp_namespace = "GrpcProject";package grpc.serviceing;service BothWaysRpc{// 双向流rpc StreamingBothWays(stream ExampleMessage) returns (stream ExampleMessage);
}

1 服务接口实现

    /// <summary>/// 双向流服务/// </summary>public class BothWaysService : BothWaysRpc.BothWaysRpcBase{/// <summary>/// 自动重置事件/// </summary>private readonly ManualResetEventSlim _event;public BothWaysService(){_event = new ManualResetEventSlim(false);}public override async Task StreamingBothWays(IAsyncStreamReader<ExampleMessage> requestStream,IServerStreamWriter<ExampleMessage> responseStream,ServerCallContext context){// 创建线程安全的有限容量通道var channel = Channel.CreateBounded<ExampleMessage>(new BoundedChannelOptions(capacity: 5));var task = Task.Run(async () =>{await foreach (var message in requestStream.ReadAllAsync()){// 读取消息 写入通道if (!string.IsNullOrWhiteSpace(message.Msg)){await Console.Out.WriteLineAsync($"记录客户端传入消息：{message.Msg}");// todo 消息处理await channel.Writer.WriteAsync(message, context.CancellationToken);}}}, context.CancellationToken);await foreach (var message in channel.Reader.ReadAllAsync()){// 打印通道接收的消息await Console.Out.WriteLineAsync($"通道传入消息：{message.Msg}");// 写入响应流ExampleMessage exampleMessage = new ExampleMessage() { Msg = $"我已经接收到消息：{message.Msg}" };await responseStream.WriteAsync(exampleMessage);if (message.Msg.ToLower() == "exit"){break;}}// 完结写入通道channel.Writer.Complete();await task;}}

2 Program注入

    public class Program{public static void Main(string[] args){var builder = WebApplication.CreateBuilder(args);builder.Services.AddGrpc();var app = builder.Build();// 一元方法//app.MapGrpcService<DollarService>();// 客户端流//app.MapGrpcService<ClientStreamService>();// 服务端流//app.MapGrpcService<ServerStreamService>();// 双向流app.MapGrpcService<BothWaysService>();app.Run();}}

四、客户端配置

引用proto文件，配置为客户端类型
根据编译生成的函数进行传参调用
创建WPF测试客户端

button按钮触发grpc

    /// <summary>/// BothWaysClient.xaml 的交互逻辑/// </summary>public partial class BothWaysClient : Window{public BothWaysClient(){InitializeComponent();}private async void Excute_Click(object sender, RoutedEventArgs e){Action<string> action = str => { txtValue.Text += $"{str}\r\n"; };await WpfClient.Show(action);txtValue.Text += "\r\n\r\n";}}

grpc客户端接口调用

        /// <summary>/// 双向流/// </summary>/// <param name="action"></param>/// <returns></returns>public static async Task Show(Action<string> action){var messages = new List<string>(){"test","one","two","three","false","four","Oooo","dddd","vvvfff","exit"};Random rnd = new Random(20);var channel = GrpcChannel.ForAddress("https://localhost:7188");var client = new GrpcProject.BothWaysRpc.BothWaysRpcClient(channel);var bothWays = client.StreamingBothWays();var requestTask = Task.Run(async () =>{while (true){var index = rnd.Next(messages.Count);var msg = messages[index];await bothWays.RequestStream.WriteAsync(new ExampleMessage { Msg = msg });if (msg == "exit"){break;}}});await foreach (var item in bothWays.ResponseStream.ReadAllAsync()){action(item.Msg);if (item.Msg == "我已经接收到消息：exit"){break;}}await requestTask;}