C# TCP 接收图片：解决套接字地址重复使用错误

{ 'title': '// 接收图片\n private void ReceiveImages()\n {\n continueReceiving = true;\n TcpListener listener = new TcpListener(IPAddress.Parse(GetLocalIPAddress()), 1025);\n\n listener.Start();\n\n while (continueReceiving)\n {\n try\n {\n\n\n\n TcpClient imageClient = listener.AcceptTcpClient();\n NetworkStream imageStream = imageClient.GetStream();\n\n // 先接收图像数据的长度\n byte[] lengthBytes = new byte[4];\n imageStream.Read(lengthBytes, 0, 4);\n int length = BitConverter.ToInt32(lengthBytes, 0);\n\n byte[] imageData = new byte[length];\n int totalBytesRead = 0;\n int bytesRead = 0;\n\n while (totalBytesRead < length &&\n (bytesRead = imageStream.Read(imageData, totalBytesRead, length - totalBytesRead)) > 0)\n {\n totalBytesRead += bytesRead;\n }\n\n if (totalBytesRead > 0)\n {\n using (MemoryStream ms = new MemoryStream(imageData))\n {\n Image receivedImage = Image.FromStream(ms);\n\n // 在PictureBox中展示图片\n pictureBox1.Image = receivedImage;\n }\n }\n // 关闭并释放套接字资源\n imageStream.Close();\n imageClient.Close();\n }\n catch (Exception ex)\n {\n MessageBox.Show(ex.ToString());\n }\n\n }\n // 停止监听并释放套接字资源\n //receiveThread.Abort();\n listener.Stop();\n } 这个接受图片的方法中，如果点击按钮1调用了Disconnect()方法，然后再次点击按钮1，则会提示 listener.Start();这一行套接字地址只允许使用一次”的错误内容：这个错误是因为在调用Disconnect()方法后，套接字listener被关闭并释放资源，所以再次调用ReceiveImages()方法时无法重新启动listener。要解决这个问题，可以在调用Disconnect()方法时加入一个标志位，表示是否已经断开连接。然后在ReceiveImages()方法中根据这个标志位来决定是否重新启动listener。

示例代码如下：

private bool isDisconnected = false;

// 断开连接
private void Disconnect()
{
    isDisconnected = true;
    // 关闭并释放套接字资源
    listener.Stop();
}

// 接收图片
private void ReceiveImages()
{
    isDisconnected = false;
    TcpListener listener = new TcpListener(IPAddress.Parse(GetLocalIPAddress()), 1025);

    listener.Start();

    while (continueReceiving && !isDisconnected)
    {
        try
        {
            TcpClient imageClient = listener.AcceptTcpClient();
            NetworkStream imageStream = imageClient.GetStream();

            // 先接收图像数据的长度
            byte[] lengthBytes = new byte[4];
            imageStream.Read(lengthBytes, 0, 4);
            int length = BitConverter.ToInt32(lengthBytes, 0);

            byte[] imageData = new byte[length];
            int totalBytesRead = 0;
            int bytesRead = 0;

            while (totalBytesRead < length &&
                   (bytesRead = imageStream.Read(imageData, totalBytesRead, length - totalBytesRead)) > 0)
            {
                totalBytesRead += bytesRead;
            }

            if (totalBytesRead > 0)
            {
                using (MemoryStream ms = new MemoryStream(imageData))
                {
                    Image receivedImage = Image.FromStream(ms);

                    // 在PictureBox中展示图片
                    pictureBox1.Image = receivedImage;
                }
            }

            // 关闭并释放套接字资源
            imageStream.Close();
            imageClient.Close();
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.ToString());
        }
    }

    if (!isDisconnected)
    {
        // 停止监听并释放套接字资源
        listener.Stop();
    }
}

在调用Disconnect()方法时，设置isDisconnected为true。在ReceiveImages()方法中，添加了一个判断条件，如果isDisconnected为true，则不重新启动listener并退出循环。这样即使断开连接后再次点击按钮1，就不会出现'套接字地址只允许使用一次'的错误了。