有關管道的基本用法請看System.IO之使用管道在進程間通信 (System.IO.Pipes使用)。
本文介紹命名管道使用實例,文中例子是幾個客戶端都通過一台服務器獲得新生成的int類型id。
服務器端功能:當客戶端請求一個新的id時,將現有id自增1,然後返回給客戶端。
服務器端實現:在程序啟動時,啟動n個線程,在每個線程中都聲明一個NamedPipeServerStream的實例,並循環的WaitForConnection(),將新的id寫入到命名管道中,然後斷開連接。在程序退出時釋放NamedPipeServerStream實例
如下代碼實現:
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| using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.IO;using System.IO.Pipes;using System.Threading;namespace IDServer{ class Program { /// <summary> /// 命名管道名字 /// </summary> private const string PIPE_NAME = "testNetworkPipe"; //定義線程數,也是NamedPipeServerStream的允許最多的實例數 private const int MAX_THREADS_COUNT = 3; private static volatile int _runingThreadCount = 0; private static volatile int _newId = 0; //實例數組 private static NamedPipeServerStream[] _serverStreams; static void Main(string[] args) { _serverStreams = new NamedPipeServerStream[MAX_THREADS_COUNT]; //在進程退出時釋放所有NamedPipeServerStream實例 AppDomain.CurrentDomain.ProcessExit += new EventHandler(CurrentDomain_ProcessExit); //啟動線程 StartServers(); Console.Read(); } /// <summary> /// 在進程退出時釋放命名管道 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> static void CurrentDomain_ProcessExit(object sender, EventArgs e) { if (_serverStreams != null) { foreach (NamedPipeServerStream item in _serverStreams) { item.Dispose(); } } } /// <summary> /// 啟動服務器端線程 /// </summary> private static void StartServers() { for (int i = 0; i < MAX_THREADS_COUNT; i++) { Thread thread = new Thread(new ThreadStart(StartNewIDServer)); thread.Start(); } } /// <summary> /// 啟動一個NamedPipeServerStream實例 /// </summary> private static void StartNewIDServer() { NamedPipeServerStream stream = null; Console.WriteLine("start server in thread " + Thread.CurrentThread.ManagedThreadId); stream = _serverStreams[_runingThreadCount] = new NamedPipeServerStream(PIPE_NAME, PipeDirection.InOut, MAX_THREADS_COUNT, PipeTransmissionMode.Message, PipeOptions.None); int threadNo = _runingThreadCount; _runingThreadCount += 1; while (true) { stream.WaitForConnection(); int newId = ++_newId; byte[] bytes = BitConverter.GetBytes(newId); stream.Write(bytes, 0, bytes.Length); stream.Flush(); Console.Write("threadNo:" + Thread.CurrentThread.ManagedThreadId + "\r"); stream.Disconnect(); } } }} |
客戶端的功能是不斷的發出獲得新id的請求,並打印新id,在客戶端可以配置服務端的服務器IP。
如下代碼:
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| using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading;namespace IDClient{ class Program { private const string PIPE_NAME = "testNetworkPipe"; static void Main(string[] args) { Console.WriteLine("請輸入任何字符回車開始執行程序.."); Console.Read(); do { //內網服務器ip,必須是局域網 string serverName = "127.0.0.1"; //聲明NamedPipeClientStream實例 using (var clientStream = new System.IO.Pipes.NamedPipeClientStream(serverName, PIPE_NAME)) { //連接服務器 clientStream.Connect(1000); //設置為消息讀取模式 clientStream.ReadMode = System.IO.Pipes.PipeTransmissionMode.Message; do { byte[] bytes = new byte[4]; clientStream.Read(bytes, 0, 4); int val = BitConverter.ToInt32(bytes, 0); Console.Write("NewID == " + val + "\r"); } while (!clientStream.IsMessageComplete); } Thread.Sleep(1); } while (true); } }} |
在sql server中就使用了命名管道在局域網內掛進程通訊。
在聲明NamedPipeServerStream實例是可以指定其實例個數,如果實例數超過這個數,就會拋出「所有管道範例都在使用中」的IO異常。
本例不可以在實際項目中使用。