在运行时更改 TextBox BackColor

Question

I've 4 textboxes and 1 button. When the button is pressed, it pings the 4 ip addresses, then changes the textboxes color according to ping status.

What I want to do is, when button is pressed all textboxes backcolor changes to white before the pings start.

I wrote the following code, but it didn't work.

My Codes:

public void Clear1()
        {
            txtHKB1.BackColor = Color.Yellow;
            txtHKB2.BackColor = Color.Yellow;
            txtHKB3.BackColor = Color.Yellow;
            txtHKB4.BackColor = Color.Yellow;
        }

        public void Clear2()
        {
            txtHKB1.Text = "";
            txtHKB2.Text = "";
            txtHKB3.Text = "";
            txtHKB4.Text = "";
        }

    private void btnConnect_Click(object sender, EventArgs e)
            {
                //b.Baglan("192.168.20.50","9050");
            }

            private void btnSistemIzle_Click(object sender, EventArgs e)
            {
                Thread th1 = new Thread(new ThreadStart(Clear1));
                Thread th2 = new Thread(new ThreadStart(Clear2));

                th1.Start();
                th2.Start();

                SistemIzle("192.168.20.60");            
                SistemIzle("192.168.20.80");
                SistemIzle("192.168.20.100");
                SistemIzle("192.168.20.120");

                counter2++;
            }

            public void SystemAnalyse(string ip)
            {
                try
                {
                    IPAddress ipAddress = Dns.GetHostEntry(ip).AddressList[0];

                    //for (int i = 0; i < 3; i++)
                    //{
                    System.Net.NetworkInformation.Ping ping = new System.Net.NetworkInformation.Ping();
                    System.Net.NetworkInformation.PingReply pingReply = ping.Send(ipAddress);

                    counter++;

                    //MessageBox.Show(pingReply.Buffer.Count().ToString() + pingReply.RoundtripTime.ToString()
                    //        + pingReply.Options.Ttl.ToString() + pingReply.Status.ToString());

                        //System.Threading.Thread.Sleep(100);
                    //}

                }

                catch
                {
                    //MessageBox.Show("Başarısız Girişim!");
                    fail++;
                }

                if (counter % 4 == 1 && fail == 0)
                {
                    txtHKB1.BackColor = Color.Green;
                    txtHKB1.Text = "                         Yayinda";
                }

                if (counter % 4 == 1 && fail == 1)
                {
                    fail = 0;
                    txtHKB1.BackColor = Color.Red;
                    txtHKB1.Text = "                         Kapalı";
                }

                if (counter % 4 == 2 && fail == 0)
                {
                    txtHKB2.BackColor = Color.Green;
                    txtHKB2.Text = "                         Yayinda";
                }

                if (counter % 4 == 2 && fail == 1)
                {
                    fail = 0;
                    txtHKB2.BackColor = Color.Red;
                    txtHKB2.Text = "                         Kapalı";
                }

                if (counter % 4 == 3 && fail == 0)
                {
                    txtHKB3.BackColor = Color.Green;
                    txtHKB3.Text = "                         Yayinda";
                }

                if (counter % 4 == 3 && fail == 1)
                {
                    fail = 0;
                    txtHKB3.BackColor = Color.Red;
                    txtHKB3.Text = "                         Kapalı";
                }

                if (counter % 4 == 0 && fail == 0)
                {
                    txtHKB4.BackColor = Color.Green;
                    txtHKB4.Text = "                         Yayinda";
                }

                if (counter % 4 == 0 && fail == 1)
                {
                    fail = 0;
                    txtHKB4.BackColor = Color.Red;
                    txtHKB4.Text = "                         Kapalı";
                }
            }

What I'm doing wrong? My best regards...

Answer 1

This code does not make much sense. You are spawning two threads just to change the color of controls that are owned by a different thread? This is wrong for many reasons:

1. Why would you need to change the color in parallel?
2. You cannot do it like this anyway, because only the UI thread can update controls, unless you use Control.Invoke or Control.BeginInvoke to forward updates from other threads, but I don't see the point in your case.

I suggest you simply do this:

        private void btnSistemIzle_Click(object sender, EventArgs e)
        {
            txtHKB1.BackColor = Color.Yellow;
            txtHKB2.BackColor = Color.Yellow;
            txtHKB3.BackColor = Color.Yellow;
            txtHKB4.BackColor = Color.Yellow;

            txtHKB1.Text = "";
            txtHKB2.Text = "";
            txtHKB3.Text = "";
            txtHKB4.Text = "";


            SistemIzle("192.168.20.60");            
            SistemIzle("192.168.20.80");
            SistemIzle("192.168.20.100");
            SistemIzle("192.168.20.120");

            counter2++;
        }

Answer 2

If I understand correctly you are using a WinForm and the texboxes do change accordingly when you ping?

To have them set to white before you ping calling this code at the beginning of the method should work. You shouldn't have to seperatly thread it. Are you threading for any specific reason?

txtHKB1.BackColor = Color.White;
txtHKB2.BackColor = Color.White;
txtHKB3.BackColor = Color.White;
txtHKB4.BackColor = Color.White;

Not sure what else could be causing it, maybe make a method then call it anywhere you need them to change back to white?

private void colorchange()
{
    txtHKB1.BackColor = Color.White;
    txtHKB2.BackColor = Color.White;
    txtHKB3.BackColor = Color.White;
    txtHKB4.BackColor = Color.White;
}

and at the start of your other button click just call.

colorchange();