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如何：使用套接字

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更新：2007 年 11 月

.NET Compact Framework 支持基于套接字的网络通信。若要了解特定于在 .NET Compact Framework 中进行套接字编程的注意事项，请参见套接字编程。

此示例创建了服务器应用程序的一个实例和客户端应用程序的一个实例，并演示了这两个应用程序如何通过基于套接字的连接进行通信。由于服务器使用的是 localhost 地址，因此两个应用程序都在客户端上运行。必须在运行服务器的实例之后，客户端才能与之通信。

通过套接字连接进行通信

  1. 创建一个用于实现 Form 的名为 Server 的类，并将下列代码添加到该类中：

    Private Shared output As String = ""


Public Sub New() 

End Sub


Public Sub createListener() 
    ' Create an instance of the TcpListener class.
    Dim tcpListener As TcpListener = Nothing
    Dim ipAddress As IPAddress = Dns.GetHostEntry("localhost").AddressList(0)
    Try
        ' Set the listener on the local IP address.
        ' and specify the port.
        tcpListener = New TcpListener(ipAddress, 13)
        tcpListener.Start()
        output = "Waiting for a connection..."
    Catch e As Exception
        output = "Error: " + e.ToString()
        MessageBox.Show(output)
    End Try
    While True
        ' Always use a Sleep call in a while(true) loop
        ' to avoid locking up your CPU.
        Thread.Sleep(10)
        ' Create a TCP socket.
        ' If you ran this server on the desktop, you could use
        ' Socket socket = tcpListener.AcceptSocket()
        ' for greater flexibility.
        Dim tcpClient As TcpClient = tcpListener.AcceptTcpClient()
        ' Read the data stream from the client.
        Dim bytes(255) As Byte
        Dim stream As NetworkStream = tcpClient.GetStream()
        stream.Read(bytes, 0, bytes.Length)
        Dim helper As New SocketHelper()
        helper.processMsg(tcpClient, stream, bytes)
    End While

End Sub


Shared Sub Main() 
    Application.Run(New Server())

End Sub


    static string output = "";

public Server()
{
}

public void createListener()
{
    // Create an instance of the TcpListener class.
    TcpListener tcpListener = null;
    IPAddress ipAddress = Dns.GetHostEntry("localhost").AddressList[0];
    try
    {
        // Set the listener on the local IP address
        // and specify the port.
        tcpListener = new TcpListener(ipAddress, 13);
        tcpListener.Start();
        output = "Waiting for a connection...";
    }
    catch (Exception e)
    {
        output = "Error: " + e.ToString();
        MessageBox.Show(output);
    }
    while (true)
    {
        // Always use a Sleep call in a while(true) loop
        // to avoid locking up your CPU.
        Thread.Sleep(10);
        // Create a TCP socket.
        // If you ran this server on the desktop, you could use
        // Socket socket = tcpListener.AcceptSocket()
        // for greater flexibility.
        TcpClient tcpClient = tcpListener.AcceptTcpClient();
        // Read the data stream from the client.
        byte[] bytes = new byte[256];
        NetworkStream stream = tcpClient.GetStream();
        stream.Read(bytes, 0, bytes.Length);
        SocketHelper helper = new SocketHelper();
        helper.processMsg(tcpClient, stream, bytes);
    }
}

static void Main()
{
    Application.Run(new Server());
}

  2. 在 Server 类中，提供启动服务器的方法。例如，在某个按钮的 Click 事件中调用 createListener。

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
    Me.createListener()
End Sub

    private void button1_Click(object sender, EventArgs e)
{
    this.createListener();
}

  3. 创建一个名为 SocketHelper 的类，并将下列代码添加到该类中：

    Class SocketHelper
    Private mscClient As TcpClient
    Private mstrMessage As String
    Private mstrResponse As String
    Private bytesSent() As Byte

    Public Sub processMsg(ByVal client As TcpClient, ByVal stream As NetworkStream, ByVal bytesReceived() As Byte)
        ' Handle the message received and 
        ' send a response back to the client.
        mstrMessage = Encoding.ASCII.GetString(bytesReceived, 0, bytesReceived.Length)
        mscClient = client
        mstrMessage = mstrMessage.Substring(0, 5)
        If mstrMessage.Equals("Hello") Then
            mstrResponse = "Goodbye"
        Else
            mstrResponse = "What?"
        End If
        bytesSent = Encoding.ASCII.GetBytes(mstrResponse)
        stream.Write(bytesSent, 0, bytesSent.Length)

    End Sub
End Class

    class SocketHelper
{
    TcpClient mscClient;
    string mstrMessage;
    string mstrResponse;
    byte[] bytesSent;
    public void processMsg(TcpClient client, NetworkStream stream, byte[] bytesReceived)
    {
        // Handle the message received and 
        // send a response back to the client.
        mstrMessage = Encoding.ASCII.GetString(bytesReceived, 0, bytesReceived.Length);
        mscClient = client;
        mstrMessage = mstrMessage.Substring(0, 5);
        if (mstrMessage.Equals("Hello"))
        {
            mstrResponse = "Goodbye";
        }
        else
        {
            mstrResponse = "What?";
        }
        bytesSent = Encoding.ASCII.GetBytes(mstrResponse);
        stream.Write(bytesSent, 0, bytesSent.Length);
    }
}

    当客户端连接到服务器时，服务器将实例化此类。

  4. 创建一个用于实现 Form 的名为 Client 的类，并将下列代码添加到该类中：

        Shared Sub Connect(ByVal serverIP As String, ByVal message As String) 
    Dim output As String = ""
    Try
            ' Create a TcpClient.
            ' The client requires a TcpServer that is connected
            ' to the same address specified by the server and port
            ' combination.
            Dim port As Int32 = 13
            Dim client As New TcpClient(serverIP, port)

            ' Translate the passed message into ASCII and store it as a byte array.
            Dim data(255) As [Byte]
            data = System.Text.Encoding.ASCII.GetBytes(message)

            ' Get a client stream for reading and writing.
            ' Stream stream = client.GetStream();
            Dim stream As NetworkStream = client.GetStream()

            ' Send the message to the connected TcpServer. 
            stream.Write(data, 0, data.Length)

            output = "Sent: " + message
            MessageBox.Show(output)

            ' Buffer to store the response bytes.
            data = New [Byte](255) {}

            ' String to store the response ASCII representation.
            Dim responseData As String = String.Empty

            ' Read the first batch of the TcpServer response bytes.
            Dim bytes As Int32 = stream.Read(data, 0, data.Length)
            responseData = System.Text.Encoding.ASCII.GetString(data, 0, bytes)
            output = "Received: " + responseData
            MessageBox.Show(output)

            ' Close everything.
            stream.Close()
            client.Close()
        Catch e As ArgumentNullException
            output = "ArgumentNullException: " + e.ToString()
            MessageBox.Show(output)
        Catch e As SocketException
            output = "SocketException: " + e.ToString()
            MessageBox.Show(output)
        End Try

    End Sub

    Shared Sub Main() 
        Application.Run(New Client())

    End Sub

     public Client()
        {
            this.MinimizeBox = false;
        }

    static void Connect(string serverIP, string message)
        {
            string output = "";

            try
            {
                // Create a TcpClient.
                // The client requires a TcpServer that is connected
                // to the same address specified by the server and port
                // combination.
                Int32 port = 13;
                TcpClient client = new TcpClient(serverIP, port);

                // Translate the passed message into ASCII and store it as a byte array.
                Byte[] data = new Byte[256];
                data = System.Text.Encoding.ASCII.GetBytes(message);

                // Get a client stream for reading and writing.
                // Stream stream = client.GetStream();
                NetworkStream stream = client.GetStream();

                // Send the message to the connected TcpServer. 
                stream.Write(data, 0, data.Length);

                output = "Sent: " + message;
                MessageBox.Show(output);

                // Buffer to store the response bytes.
                data = new Byte[256];

                // String to store the response ASCII representation.
                String responseData = String.Empty;

                // Read the first batch of the TcpServer response bytes.
                Int32 bytes = stream.Read(data, 0, data.Length);
                responseData = System.Text.Encoding.ASCII.GetString(data, 0, bytes);
                output = "Received: " + responseData;
                MessageBox.Show(output);

                // Close everything.
                stream.Close();
                client.Close();
            }
            catch (ArgumentNullException e)
            {
                output = "ArgumentNullException: " + e;
                MessageBox.Show(output);
            }
            catch (SocketException e)
            {
                output = "SocketException: " + e.ToString();
                MessageBox.Show(output);
            }
        }

    static void Main()
        {
            Application.Run(new Client());
        }

  5. 在 Client 类中，为用户提供连接到服务器的方法。例如，在某个按钮的 Click 事件中调用 Connect 方法。

    Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) 
    ' In this code example, use a hard-coded
    ' IP address and message.
    Dim serverIP As String = "localhost"
    Dim message As String = "Hello"
    Connect(serverIP, message)

End Sub

    private void button1_Click(object sender, EventArgs e)
{
    // In this code example, use a hard-coded
    // IP address and message.
    string serverIP = "localhost";
    string message = "Hello";
    Connect(serverIP, message);
}

  6. 编译服务器和客户端应用程序。

  7. 将两个应用程序部署到设备。

  8. 在设备上运行服务器应用程序并启动服务器。

  9. 在设备上运行客户端应用程序并连接到服务器。

编译代码

客户端程序需要引用以下命名空间：

服务器程序需要引用以下命名空间：

请参见

其他资源

.NET Compact Framework 中的网络和连接