Question

我有一个程序将数据发送到服务器，并在尝试发送数据时冻结。

  Dim postData = "000000001119001  MY0121     020216081825S0000000001233300000000002050"
                Dim client As New TcpClient(IPAddressTextbox.Text, 17476)

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

                ' 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)

                Console.WriteLine("Sent: {0}", postData)

                ' Receive the TcpServer.response.
                ' Buffer to store the response bytes.

                data = New [Byte](256) {}

                ' 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)

                Console.WriteLine("Received: {0}", responseData)
                ResponseBox.Text = responseData
                ' Close everything.
                stream.Close()
                client.Close()

我做了一些故障排除，发现它冻结了这一行

Dim bytes As Int32 = stream.Read(data, 0, data.Length)

我从Here获得了这段代码，因为我刚开始学习TCP连接，并认为微软可能是一个很好的资源来学习。我已经验证服务器IP和端口是有效的，并接受我的连接。

Answer 1

认为微软可能是一个很好的资源来学习

哈哈哈...... :( MSDN套接字代码是最难找到的套接字代码之一。

如果读取“挂起”，则意味着远程端甚至不发送单个字节。我的猜测：您的请求格式错误或不完整。另一方正在等你发送完整的数据。

请注意，读取可能是部分的。您通常需要循环，直到获得所需的所有数据。假设每次读取只返回一个字节。您的代码必须能够处理它。您可以尝试new StreamReader(new NetworkStream(socket)).ReadToEnd()。

这个Microsoft示例代码只是可耻的：

// 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);
Console.WriteLine("Received: {0}", responseData);

他们确实说这是“第一批”，但仍然使代码破碎。

程序在VB.NET中通过TCP / IP发送数据时冻结

1 个答案: