Stop Thread on Button Click in C#

Question

I want to stop my thread on button click event and As I am new to threads I don't know how can I do this in C#. My application is of TCP Client and I am reading TCP server continuously using this thread

public void ClientReceive()
{
    try
    {

        stream = client.GetStream(); //Gets The Stream of The Connection
        new Thread(() => // Thread (like Timer)
        //Thread mythread = new Thread(ClientReceive);
        {
            //MessageBox.Show(stream.Read(datalength, 0, 256).ToString());
            //(i = stream.Read(datalength, 0, 256)) != 0
            while (i != 1)//Keeps Trying to Receive the Size of the Message or Data
            {
                // how to make a byte E.X byte[] examlpe = new byte[the size of the byte here] , i used BitConverter.ToInt32(datalength,0) cuz i received the length of the data in byte called datalength :D
                // byte[] data = BitConverter.GetBytes(1000); // Creates a Byte for the data to be Received On
                byte[] data = new byte[1000];
                stream.Read(data, 0, data.Length); //Receives The Real Data not the Size
                this.Invoke((MethodInvoker)delegate // To Write the Received data
                {
                    //txtLog.Text += System.Environment.NewLine + "Server : " + Encoding.Default.GetString(data); // Encoding.Default.GetString(data); Converts Bytes Received to String
                    DateTime now = DateTime.Now;
                    //MessageBox.Show(Encoding.Default.GetString(data));
                    if (Encoding.Default.GetString(data) != "")
                    {
                        txtLog.Text += System.Environment.NewLine + now.ToString() + " Received : \r\n" + Encoding.Default.GetString(data) + "\r\n";

                    }
                    for (int j = 0; j < txtLog.Lines.Length; j++)
                    {
                        if (txtLog.Lines[j].Contains("Received"))
                        {
                            this.CheckKeyword(txtLog.Lines[j + 1], Color.Red, 0);
                        }
                        if (txtLog.Lines[j].Contains("Sent"))
                        {
                            this.CheckKeyword(txtLog.Lines[j + 1], Color.Blue, 0);
                        }
                    }

                });
            }
       // mythread.Start();
        }).Start(); // Start the Thread
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.ToString());  
    }
}

Answer 1

I recommend you to use Task instead of Thread. Because Aborting a thread is not recommnded and it may affect your data as well.

Eric Lippert explained it very well here.

Here is the code for you:

private CancellationTokenSource tokenSource; //global field

public void ClientReceive()
{
    try
    {
        //initiate CancellationTokenSource
        tokenSource = new CancellationTokenSource();

        stream = client.GetStream(); //Gets The Stream of The Connection

        //start parallel task
        Task.Factory.StartNew(() =>
        {           
            //MessageBox.Show(stream.Read(datalength, 0, 256).ToString());
            //(i = stream.Read(datalength, 0, 256)) != 0
            while (i != 1)//Keeps Trying to Receive the Size of the Message or Data
            {
                // how to make a byte E.X byte[] examlpe = new byte[the size of the byte here] , i used BitConverter.ToInt32(datalength,0) cuz i received the length of the data in byte called datalength :D
                // byte[] data = BitConverter.GetBytes(1000); // Creates a Byte for the data to be Received On
                byte[] data = new byte[1000];
                stream.Read(data, 0, data.Length); //Receives The Real Data not the Size
                this.Invoke((MethodInvoker)delegate // To Write the Received data
                {
                    //txtLog.Text += System.Environment.NewLine + "Server : " + Encoding.Default.GetString(data); // Encoding.Default.GetString(data); Converts Bytes Received to String
                    DateTime now = DateTime.Now;
                    //MessageBox.Show(Encoding.Default.GetString(data));
                    if (Encoding.Default.GetString(data) != "")
                    {
                        txtLog.Text += System.Environment.NewLine + now.ToString() + " Received : \r\n" + Encoding.Default.GetString(data) + "\r\n";

                    }
                    for (int j = 0; j < txtLog.Lines.Length; j++)
                    {
                        if (txtLog.Lines[j].Contains("Received"))
                        {
                            this.CheckKeyword(txtLog.Lines[j + 1], Color.Red, 0);
                        }
                        if (txtLog.Lines[j].Contains("Sent"))
                        {
                            this.CheckKeyword(txtLog.Lines[j + 1], Color.Blue, 0);
                        }
                    }

                });
            }
        }, tokenSource.Token);
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.ToString());  
    }
}

//call this method on cancel button
private void cancelTask()
{
    if(tokenSource != null) //check if its even initialized or not
        tokenSource.Cancel();
}

If you need more explanation about TPL refer to this article.