C# Winform cilent call SignalR

一、SignalR是什么

Asp.net SignalR是微軟為實現實時通信的一個類庫。一般情況下，SignalR會使用JavaScript的長輪詢(long polling)的方式來實現客戶端和服務器通信，隨着Html5中WebSockets出現，SignalR也支持WebSockets通信。另外SignalR開發的程序不僅僅限制於宿主在IIS中，也可以宿主在任何應用程序，包括控制台，客戶端程序和Windows服務等，另外還支持Mono，這意味着它可以實現跨平台部署在Linux環境下。

SignalR內部有兩類對象：

Http持久連接(Persisten Connection)對象：用來解決長時間連接的功能。還可以由客戶端主動向服務器要求數據，而服務器端不需要實現太多細節，只需要處理PersistentConnection 內所提供的五個事件：OnConnected, OnReconnected, OnReceived, OnError 和 OnDisconnect 即可。

Hub（集線器）對象：用來解決實時(realtime)信息交換的功能，服務端可以利用URL來注冊一個或多個Hub，只要連接到這個Hub，就能與所有的客戶端共享發送到服務器上的信息，同時服務端可以調用客戶端的腳本。

SignalR將整個信息的交換封裝起來，客戶端和服務器都是使用JSON來溝通的，在服務端聲明的所有Hub信息，都會生成JavaScript輸出到客戶端，.NET則依賴Proxy來生成代理對象，而Proxy的內部則是將JSON轉換成對象。

二、為什么要用SignalR

聊天室，如在線客服系統，IM系統等

消息的實時推送服務

巡更人員位置的實時推送

 

 

 

1. server     -------- 創建一個MVC 項目,選擇新建的項目，右擊-->選擇管理NuGet程序包-->搜索 signalr--> 安裝Microsoft ASP.NET SignalR

新建啟動程序 Startup.cs

在類中添加代碼：

1. app.MapSignalR();

在集線器類ChatHub.cs中添加如下代碼

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Web;
using Microsoft.AspNet.SignalR;
using System.Threading.Tasks;
namespace ChatServer
{
    public class ChatHub : Hub
    {
        public void Hello()
        {
            //Clients.All.hello();
            //Clients.All.AddMsg();
        }


        /// <summary>
        /// 供客戶端調用的服務器端代碼
        /// </summary>
        /// <param name="message"></param>
        public void Send(string name,string message)
        {
            // 調用所有客戶端的sendMessage方法
            Clients.All.sendMessage(name, message);
            Trace.WriteLine("調用所有客戶端的sendMessage方法");

        }

        /// <summary>
        /// 客戶端連接的時候調用
        /// </summary>
        /// <returns></returns>
        public override Task OnConnected()
        {
            Trace.WriteLine("客戶端連接成功");
            return base.OnConnected();
        }

    }
}

　　

 

 

 

2. 客戶端（winform）

 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using Microsoft.AspNet.SignalR.Client;
namespace ChatClient
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            Text = "Test SignalR";
            FormClosing += Form1_FormClosing;
        }

  
        public IHubProxy HubProxy { get; set; }
        const string ServerURI = "https://localhost:44306/";//ServerURI = "https://localhost:44306/signalr";
        public HubConnection Connection { get; set; }



        /// <summary>
        /// Creates and connects the hub connection and hub proxy. This method
        /// is called asynchronously 
        /// </summary>
        private async void ConnectAsync()
        {
            Connection = new HubConnection(ServerURI);
            Connection.Closed += ShowConnectionClosed;
            HubProxy = Connection.CreateHubProxy("ChatHub");
            //Handle incoming event from server: use Invoke to write to console from SignalR's thread
            HubProxy.On<string, string>("sendMessage", (name, message) =>

                   {
                       this.Invoke(
                           new Action(() =>
                           {
                               RichTextBoxConsole.AppendText(String.Format("{0}: {1}\r", name, message));
                           }
                           ));
                   }
            );

            try
            {
                await Connection.Start();
            }
            catch (HttpRequestException)
            {
                Text = "Unable to connect to server: Start server before connecting clients.";
                //No connection: Don't enable Send button or show chat UI
                return;
            }

            TextBoxMessage.Focus();
            RichTextBoxConsole.AppendText("Connected to server at " + ServerURI + "\r");
        }
        private void CloseConnection()
        {
            if (Connection != null)
            {
                Connection.Stop();
                Connection.Dispose();
            }
        }

        /// <summary>
        /// If the server is stopped, the connection will time out after 30 seconds (default), and the 
        /// Closed event will fire.
        /// </summary>
        private void ShowConnectionClosed()
        {
            RichTextBoxConsole.AppendText("You have been disconnected.\r\n");
        }

        private void btnConnect_Click(object sender, EventArgs e)
        {
            RichTextBoxConsole.AppendText("Connecting to server...");
            ConnectAsync();
        }
        private void btnSend_Click(object sender, EventArgs e)
        {
            if (Connection.State == Microsoft.AspNet.SignalR.Client.ConnectionState.Disconnected)
            {
                ShowConnectionClosed();
                return;
            }
            HubProxy.Invoke("Send", "Client wgscd", TextBoxMessage.Text);
            TextBoxMessage.Text = String.Empty;
            TextBoxMessage.Focus();
        }
        private void btnDisconnect_Click(object sender, EventArgs e)
        {
            CloseConnection();
        }
        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            CloseConnection();
        }

     
    }
}