private static void ConnectThreaded(object state)
{
ConnectorState cs = (ConnectorState)state;
cs.Thread = Thread.CurrentThread;
try
{
TcpClient tc = new TcpClient(cs.Hostname, cs.Port);
if (cs.Aborted)
{
try { tc.GetStream().Close(); }
catch { }
try { tc.Close(); }
catch { }
}
else
{
cs.TcpClient = tc;
cs.Completed.Set();
}
}
catch (Exception e)
{
cs.Exception = e;
cs.Completed.Set();
}
}
/// <summary>
/// 在指定时间内尝试连接指定主机上的指定端口。
/// </summary>
/// <param name="hostname">要连接到的远程主机的 DNS 名。</param>
/// <param name="port">要连接到的远程主机的端口号。</param>
/// <param name="millisecondsTimeout">要等待的毫秒数，或 -1 表示无限期等待。</param>
/// <returns>已连接的一个 TcpClient 实例。</returns>
/// <remarks>本方法可能抛出的异常与 TcpClient 的构造函数重载之一
/// public TcpClient(string, int) 相同，并若指定的等待时间是个负数且不等于
/// -1，将会抛出 ArgumentOutOfRangeException。</remarks>
public static TcpClient Connect(string hostname, int port, int millisecondsTimeout)
{
ConnectorState cs = new ConnectorState();
cs.Hostname = hostname;
cs.Port = port;
ThreadPool.QueueUserWorkItem(new WaitCallback(ConnectThreaded), cs);
if (cs.Completed.WaitOne(millisecondsTimeout, false))
{
if (cs.TcpClient != null)
{
return(cs.TcpClient);
}
throw cs.Exception;
}
else
{
cs.Abort();
throw new SocketException(11001); // cannot connect
}
}
