TcpClient -现有连接被远程主机强制关闭。
TcpClient -现有连接被远程主机强制关闭。
提问于 2014-07-15 20:05:06
The Info
我一直在c#中开发一个web http服务器，并决定添加一个远程控制台功能。控制台可以从任何位置使用，并使用TcpListener (web服务器)和TcpClient (远程控制台)发送命令和函数。
代码
这就是我的服务器的样子：
TcpListener consoleListener = new TcpListener(consolePort);
consoleListener.Start();
byte[] bytes = new Byte[256];
string data = null;
while (true)
{
TcpClient client = consoleListener.AcceptTcpClient();
data = null;
byte[] msg = { 0 };
int i;
while ((i = client.GetStream().Read(bytes, 0, bytes.Length)) != 0)
{
data = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
if (data == "shutdown")
{
//Server shutdown logic.
}
//Other commands here...
else
{
msg = Encoding.ASCII.GetBytes("Invalid command. Type 'help' or '?' to get a list of commands.");
}
client.GetStream().Write(msg, 0, msg.Length); //sends return message to console
}
client.Close(); //closes connection between client and server after EVERY command. Connection is reopened when a new command is sent.
}注意-服务器在一个单独的线程上运行，同时运行到webserver和主控制台应用程序线程。
这是我的客户：
public static string Communicate(string text)
{
try
{
TcpClient client = new TcpClient(ip, port); //initializes tcpclient (ip and port are correct)
byte[] data = System.Text.Encoding.ASCII.GetBytes(text); //converts text to bytes for stream writing
NetworkStream stream = client.GetStream();
stream.Write(data, 0, data.Length);
Console.WriteLine("Sent data: " + text);
data = new Byte[256];
string responseData = String.Empty; //initializes responsData string
Int32 bytes = stream.Read(data, 0, data.Length);
responseData = System.Text.Encoding.ASCII.GetString(data, 0, bytes);
client.Close();
return responseData; //returns what server writes
}
catch (Exception ex)
{
return "An error occured\n" + ex.ToString();
}
}问题
我可以向服务器发送一个命令，并成功返回。但是，当我尝试发送另一个命令时，服务器会抛出以下错误：
System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host. ---> System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
--- End of inner exception stack trace ---
at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)
at ---.Server.ConsoleListener() in X:\Users\---\Documents\Visual Studio 2013\Projects\---\---\Program.cs:line x我知道这不是防火墙或管理员提升问题，因为我可以成功地发送一个命令。只有在发送的第二个命令中，它才会抛出此错误。
下面是一个描述问题的屏幕截图：
编辑:通过做一些研究，我发现这个问题很可能是我的for循环中的一个小错误造成的。但是，我不知道如何解决这个问题，因为我不知道确切的问题:)。请帮我确认一下，这样我就能修好它了。
再次感谢
回答 2
Stack Overflow用户
回答已采纳
发布于 2014-07-15 20:29:18
似乎您的客户在一条消息之后关闭了连接。
responseData = System.Text.Encoding.ASCII.GetString(data, 0, bytes);
client.Close();
return responseData; //returns what server writes如果您想要持久化连接，您应该在客户机上有一个类似于服务器上的循环。如果您想每次建立一个新的连接，您应该在服务器上优雅地关闭流，而不是像这样有一个循环。如果消息较长，或者需要为命令指定最大长度，则仍然需要循环。
Stack Overflow用户
发布于 2019-01-09 03:40:48
我也有同样的解决方案。如果客户端断开连接，通常会发生这种情况。不幸的是，Alex的解决方案不起作用。你会得到另一个例外。最佳解决方案由Microsoft描述为这里。
您需要使用CanRead进行检查
TcpClient tcpClient = new TcpClient ();
// Uses the GetStream public method to return the NetworkStream.
NetworkStream netStream = tcpClient.GetStream ();
if (netStream.CanRead)
{
// Reads NetworkStream into a byte buffer.
byte[] bytes = new byte[tcpClient.ReceiveBufferSize];
// Read can return anything from 0 to numBytesToRead.
// This method blocks until at least one byte is read.
netStream.Read (bytes, 0, (int)tcpClient.ReceiveBufferSize);
// Returns the data received from the host to the console.
string returndata = Encoding.UTF8.GetString (bytes);
Console.WriteLine ("This is what the host returned to you: " + returndata);
}
else
{
Console.WriteLine ("You cannot read data from this stream.");
tcpClient.Close ();
// Closing the tcpClient instance does not close the network stream.
netStream.Close ();
return;
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/24767184
复制相关文章
相似问题
腾讯云开发者
