Socket上Connected属性的MSDN文档说明如下：
The value of the Connected property
reflects the state of the connection
as of the most recent operation. If
you need to determine the current
state of the connection,make a
nonblocking,zero-byte Send call. If
the call returns successfully or
throws a WAEWOULDBLOCK error code
(10035),then the socket is still
connected; otherwise,the socket is no
longer connected.
我需要确定连接的当前状态 – 如何进行非阻塞,零字节发送调用？
解决方法
Socket.Connected属性(至少.NET 3.5版本)的MSDN文档底部的示例显示了如何执行此操作：
// .Connect throws an exception if unsuccessful
client.Connect(anEndPoint);
// This is how you can determine whether a socket is still connected.
bool blockingState = client.Blocking;
try
{
byte [] tmp = new byte[1];
client.Blocking = false;
client.Send(tmp,0);
Console.WriteLine("Connected!");
}
catch (SocketException e)
{
// 10035 == WSAEWOULDBLOCK
if (e.NativeErrorCode.Equals(10035))
Console.WriteLine("Still Connected,but the Send would block");
else
{
Console.WriteLine("Disconnected: error code {0}!",e.NativeErrorCode);
}
}
finally
{
client.Blocking = blockingState;
}
Console.WriteLine("Connected: {0}",client.Connected);
