How i wait the return value of a function-CodePudding

I have function i use for send message to server. The server return string like 'true' or 'false' and the client return the value returned by the server. My problem is when i call ClientReturn with my request i got my return in the function but not into another function string or if(ClientReturn() == "false / true") it's empty

    public static string ClientReturn(string ip, int port, string message)
    {
        string toReturn = "";
        BackgroundWorker worker = new BackgroundWorker();
        worker.DoWork  = delegate (object s, DoWorkEventArgs args)
        {
            //---data to send to the server---
            string textToSend = message;

            //---create a TCPClient object at the IP and port no.---
            TcpClient client = new TcpClient(ip, port);
            NetworkStream nwStream = client.GetStream();
            byte[] bytesToSend = ASCIIEncoding.ASCII.GetBytes(textToSend);

            //---send the text---
            Console.WriteLine("Sending : "   textToSend);
            nwStream.Write(bytesToSend, 0, bytesToSend.Length);

            //---read back the text---
            byte[] bytesToRead = new byte[client.ReceiveBufferSize];
            int bytesRead = nwStream.Read(bytesToRead, 0, client.ReceiveBufferSize);
            toReturn = Encoding.ASCII.GetString(bytesToRead, 0, bytesRead);
            Console.WriteLine("Returned: "   toReturn); //It's the return of the server
            client.Close();
        };
        worker.RunWorkerAsync();
        return toReturn; //Return the value but not work it's return nothing
    }

CodePudding user response：

The problem is that you are not waiting for the BackgroundWorker to complete.

To be honest, BackgroundWorker is obsolete anyway. Instead use async and await.

You are also missing using blocks to dispose the client and stream.

public static string ClientReturn(string ip, int port, string textToSend)
{
    //---create a TCPClient object at the IP and port no.---
    using (TcpClient client = new TcpClient())
    {
        await client.ConnectAsync(ip, port);
        using (NetworkStream nwStream = client.GetStream())
        {
            byte[] bytesToSend = Encoding.ASCII.GetBytes(textToSend);

            //---send the text---
            Console.WriteLine("Sending : "   textToSend);
            await nwStream.WriteAsync(bytesToSend, 0, bytesToSend.Length);

            //---read back the text---
            byte[] bytesToRead = new byte[client.ReceiveBufferSize];
            int bytesRead = await nwStream.ReadAsync(bytesToRead, 0, client.ReceiveBufferSize);
            var toReturn = Encoding.ASCII.GetString(bytesToRead, 0, bytesRead);
            Console.WriteLine("Returned: "   toReturn); //It's the return of the server
            return toReturn; //Return the value but not work it's return nothing
        };
    }
}