ClientWebSocket method throw new InvalidOperationException(SR.GetString(SR.net_WebSockets_AlreadyStarted))

Question

ClientWebSocket method throw new InvalidOperationException(SR.GetString(SR.net_WebSockets_AlreadyStarted))

websocket_net_WebSockets_AlreadyStarted 1

hi all!
In thread method, using System.Net.WebSockets.ClientWebSocket class method ConnectAsync, but sometimes throw exception like this " new InvalidOperationException(SR.GetString(SR.net_WebSockets_AlreadyStarted))", sometimes is ok, can you help me ?

some code as follows：
try
{
ConnectAsync(new Uri(_url), new CancellationToken()).Wait()
}
catch (Exception ex)
{
....... // here, new InvalidOperationException(SR.GetString(SR.net_WebSockets_AlreadyStarted))
}

Jiachen Li-MSFT 34,241 Reputation points Microsoft External Staff

2022-08-09T08:21:28.407+00:00

Hi @websocket_net_WebSockets_AlreadyStarted ,
Could you please provide more informaiton about the error message?
websocket_net_WebSockets_AlreadyStarted 1 Reputation point

2022-08-10T02:24:14.86+00:00
ok, thanks for your help.

First process code:

Thread thread = new Thread(new ParameterizedThreadStart(Method));
thread.IsBackground = true;
thread.Start.....

Net.WebSockets.ClientWebSocket cws = new System.Net.WebSockets.ClientWebSocket();

public static void Method(string url)
{ try
{
for(int i = 0; i < 500; i++)
{
if (CommVariable.cws .State != System.Net.WebSockets.WebSocketState.Open)
{
cws.ConnectAsync(new Uri(url), new CancellationToken()).Wait();
}
byte[] bsend = System.Text.Encoding.UTF8.GetBytes(_msg);
cws.SendAsync(new ArraySegment<byte>(bsend), System.Net.WebSockets.WebSocketMessageType.Text, true, new CancellationToken()).Wait();

` }

} catch (Exception ex) { // here InvalidOperationException(SR.GetString(SR.net_WebSockets_AlreadyStarted)); }

}

websocket_net_WebSockets_AlreadyStarted 1

Another Process Using Fleck.WebSocketServer as Server to receive the msg by First Process' websocket sending..., code as follows:

       Fleck.WebSocketServer websocket_server_ = new WebSocketServer("ws://127.0.0.1:" + port.ToString());  
        ws_server_.RestartAfterListenError = true;  
        websocket_server_.Start(socket =>  
   {  
             socket.OnMessage = msg =>    
            {                     
                HandleMessage(msg);  
            };  
        });