我知道StackOverflow上已经有几个问题询问该特定异常,但是我没有找到解决我问题的答案。
以下是相关代码段:
public static class Server
{
public const string LocalHost = "http://127.0.0.1";
public const int Port = 31311;
public static readonly string FullAddress = $"{LocalHost}:{Port}";
private static readonly TimeSpan RetryConnectionInterval = TimeSpan.FromSeconds(10);
public static async Task AwaitStart()
{
try
{
TcpClient tcpClient = new TcpClient();
ConnectionState connectionState = new ConnectionState(tcpClient);
tcpClient.BeginConnect(
host: HostAddress,
port: Port,
requestCallback: PingCallback,
state: connectionState);
bool startedSuccessfully = connectionState.IsSuccess;
while (!startedSuccessfully)
{
await Task.Delay(RetryConnectionInterval);
startedSuccessfully = connectionState.IsSuccess;
}
}
catch (Exception exception)
{
Console.WriteLine(exception.Message);
}
}
private static void PingCallback(IAsyncResult result)
{
ConnectionState state = (ConnectionState)result.AsyncState;
try
{
state.TcpClient.EndConnect(result);
state.IsSuccess = true;
Console.WriteLine("The server is successfully started.");
}
catch (SocketException)
{
Console.WriteLine($"The server is not yet started. Re-attempting connection in {RetryConnectionInterval.Seconds} seconds.");
Wait(RetryConnectionInterval).GetAwaiter().GetResult();
state.TcpClient.BeginConnect(host: HostAddress, port: Port, requestCallback: PingCallback, state: state);
}
}
private static async Task Wait(TimeSpan duration)
{
await Task.Delay(duration);
}
}
public class ConnectionState
{
public bool IsSuccess;
public readonly TcpClient TcpClient;
public ConnectionState(TcpClient tcpClient)
{
this.TcpClient = tcpClient;
}
}
该异常捕获在catch
的{{1}}子句中,并显示错误消息“未知此类主机”。
运行PingCallback(IAsyncResult result)
时,我可以看到本地服务器确实在侦听端口31311:
如果我将netstat -an
更改为TcpClient tcpClient = new TcpClient();
,则会在此处引发相同的异常(带有相同的错误消息)。
如何解决此问题?
答案 0 :(得分:1)
主机名指定错误。尝试在不使用异步的情况下进行通话应该如下所示。
TcpClient tcpClient = new TcpClient("127.0.0.1", 31311);
在异步连接中,您应指定以下内容
tcpClient.BeginConnect(host: "127.0.0.1", ...)
这应该解决