最近在一次项目中使用到了C#中命名管道，所以在此写下一篇小结备忘。
为什么要使用命名管道呢？为了实现两个程序之间的数据交换。假设下面一个场景。在同一台PC上，程序A与程序B需要进行数据通信，此时我们就可以使用命名管道技术来实现。命名管道的两个对象。NamedPipeClientStream 和 NamedPipeServerStream 对象。请求通信的一方为Client端，发送数据的一方为Server端。
使用NamedPipe来通信，如果Server端崩溃了，不会影响到客户端。
下面我们通过一个例子来说明：
Server端：
UI:
<Grid> <Grid.RowDefinitions> <RowDefinition Height="*"/> <RowDefinition Height="Auto"/> <RowDefinition Height="Auto"/> <RowDefinition Height="*"/> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto"/> <ColumnDefinition Width="*"/> </Grid.ColumnDefinitions> <TextBlock Text="Received Message:" Grid.Row="1" Margin="10"/> <TextBlock x:Name="tblRecMsg" VerticalAlignment="Center" Grid.Row="1" Grid.Column="1"/> <Button Content="Send" Grid.Row="2" Margin="10" Click="OnSend"/> <TextBox x:Name="txtSendMsg" VerticalAlignment="Center" Grid.Row="2" Grid.Column="1" Margin="10"/> </Grid>
Code:
private NamedPipeServerStream _pipe; private const string PipeName = "PipeSample"; private const int PipeInBufferSize = 4096; private const int PipeOutBufferSize = 65535; private Encoding encoding = Encoding.UTF8; public MainWindow() { InitializeComponent(); _pipe = new NamedPipeServerStream ( PipeName, PipeDirection.InOut, 1, PipeTransmissionMode.Message, PipeOptions.Asynchronous | PipeOptions.WriteThrough, PipeInBufferSize, PipeOutBufferSize ); _pipe.BeginWaitForConnection(WaitForConnectionCallback, _pipe); } private void WaitForConnectionCallback(IAsyncResult ar) { var pipeServer = (NamedPipeServerStream)ar.AsyncState; pipeServer.EndWaitForConnection(ar); var data = new byte[PipeInBufferSize]; var count = pipeServer.Read(data, 0, PipeInBufferSize); if (count > 0) { // 通信双方可以约定好传输内容的形式，例子中我们传输简单文本信息。 string message = encoding.GetString(data, 0, count); Dispatcher.BeginInvoke(new Action(() => { tblRecMsg.Text = message; })); } } private void OnSend(object sender, RoutedEventArgs e) { if (_pipe.IsConnected) { try { string message = txtSendMsg.Text; byte[] data = encoding.GetBytes(message); _pipe.Write(data, 0, data.Length); _pipe.Flush(); _pipe.WaitForPipeDrain(); } catch { } } Close(); }
Client端：
UI:
<Grid> <Grid.RowDefinitions> <RowDefinition Height="*"/> <RowDefinition Height="Auto"/> <RowDefinition Height="Auto"/> <RowDefinition Height="*"/> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto"/> <ColumnDefinition Width="*"/> </Grid.ColumnDefinitions> <Button Content="Connect" Margin="10" Click="OnConnect"/> <TextBlock Text="Received Message:" Grid.Row="1" Margin="10"/> <TextBlock x:Name="tblRecMsg" Grid.Row="1" Grid.Column="1"/> </Grid>
Code:
private const string PipeServerName = "PipeServer.exe"; private const string PipeName = "PipeSample"; private Encoding encoding = Encoding.UTF8; private NamedPipeClientStream _pipe; private bool _starting = false; public MainWindow() { InitializeComponent(); } private void OnConnect(object sender, RoutedEventArgs e) { if (_starting) { return; } var path = System.IO.Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory, PipeServerName); var startInfo = new ProcessStartInfo(path) { UseShellExecute = false, CreateNoWindow = true }; try { var process = Process.Start(startInfo); _pipe = new NamedPipeClientStream ( ".", PipeName, PipeDirection.InOut, PipeOptions.Asynchronous | PipeOptions.WriteThrough ); _pipe.Connect(); _pipe.ReadMode = PipeTransmissionMode.Message; string message = "Connected!"; byte[] data = encoding.GetBytes(message); _pipe.BeginWrite(data, 0, data.Length, PipeWriteCallback, _pipe); _starting = true; } catch (Exception ex) { Debug.Write(ex.StackTrace); } } private void PipeWriteCallback(IAsyncResult ar) { var pipe = (NamedPipeClientStream)ar.AsyncState; pipe.EndWrite(ar); pipe.Flush(); pipe.WaitForPipeDrain(); var data = new byte[65535]; var count = pipe.Read(data, 0, data.Length); if (count > 0) { string message = encoding.GetString(data, 0, count); Dispatcher.BeginInvoke(new Action(() => { tblRecMsg.Text = message; })); } }
需要注意的地方：因为我们在同一台PC上面进行通信，我们只需要将 NamedPipeClientStream 构造参数中pipeServer设为"."即可。另外因为这只是一个示例，所以PipeServer中只传递简单String类型。当然也可以传递其他类型的内容。
运行效果：
感谢您的阅读！