Using GetActiveTcpConnections to continuously check for new IP-CodePudding

I"m new to C# and am looking to see if the way I'm using this code to check for a new connection in a background worker is safe and or a better why to do it. My end goal is to run this as a service but, I'm using the background worker as a way to get real-time updates for testing. The code works but I don't know if its safe/stable or the best way to do it?

Any help would be appreciated.


private void button1_Click(object sender, EventArgs e)
{

    backgroundWorker1.WorkerSupportsCancellation = true;
    backgroundWorker1.RunWorkerAsync(2000);
    MessageBox.Show("Started backgroung worker");
}

private void button2_Click(object sender, EventArgs e)
{
    if (!backgroundWorker1.IsBusy)
    {
        backgroundWorker1.CancelAsync();
    }
    MessageBox.Show("Stopped backgroung worker");
}

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
    BackgroundWorker helperBW = sender as BackgroundWorker;
    
    e.Result = BackgroundProcessLogicMethod(helperBW, arg);
    if (helperBW.CancellationPending)
    {
        e.Cancel = true;
    }
}

private int BackgroundProcessLogicMethod(BackgroundWorker bw, int a)
{
    while (true)
    {
        IPGlobalProperties properties = IPGlobalProperties.GetIPGlobalProperties();
        TcpConnectionInformation[] connections = properties.GetActiveTcpConnections();
        foreach (TcpConnectionInformation c in connections)
        {
            if (c.RemoteEndPoint.ToString() == "192.168.4.14:443")
                 richTextBox1.Invoke(new Action( () =>    richTextBox1.AppendText(c.RemoteEndPoint.ToString()   "\n\r") ) );
        }
    }

}

CodePudding user response：

Consider throttling the while(true)... loop but other than that you seem to be doing the right things in your post. This kind of thing shows up a lot in my own production code so I wanted to offer the tried-and-true approach that works for me. It's just another perspective, however.

Your code references RichTextBox which makes me infer that a WinForms example will fly here, but the general approach is valid regardless of platform anyway.

public partial class MainForm : Form
{
    public MainForm()
    {
        InitializeComponent();
        checkBoxRun.CheckedChanged  = onRunChanged;
    }

    CancellationTokenSource _cts = null;
    private async void onRunChanged(object sender, EventArgs e)
    {
        if (checkBoxRun.Checked)
        {
            _cts = new CancellationTokenSource();
            while (checkBoxRun.Checked)
            {
                richTextBox1.AppendTextOnUIThread(DateTime.Now.ToString());
                IPGlobalProperties properties = IPGlobalProperties.GetIPGlobalProperties();
                TcpConnectionInformation[] connections = properties.GetActiveTcpConnections();
                foreach (TcpConnectionInformation c in connections)
                {
                    var endpoint = c.RemoteEndPoint.ToString();
                    switch (endpoint)
                    {
                        case "192.168.4.14:443":
                            richTextBox1.AppendTextOnUIThread(endpoint, color: Color.Red);
                            break;
                        case "127.0.0.1:49813":
                            richTextBox1.AppendTextOnUIThread(endpoint, color: Color.Blue);
                            break;
                        case "127.0.0.1:55846":
                            richTextBox1.AppendTextOnUIThread(endpoint, color: Color.Green);
                            break;
                        default:
                            continue;

                    }
                }
                richTextBox1.AppendTextOnUIThread();
                // Throttle the polling to a reasonable repeat rate.
                var task = Task.Delay(TimeSpan.FromSeconds(1), _cts.Token);
                try{ await task; } catch (TaskCanceledException){ Debug.WriteLine("Cancelled"); }
            }
        }
        else _cts.Cancel();
    }
}

With the following extension for RichTextBox:

static class Extensions
{
    public static void AppendTextOnUIThread(this RichTextBox @this, string text = "", bool newLine = true, Color? color = null)
    {
        if ([email protected])
        {
            if (newLine) text = $"{text}{Environment.NewLine}";
            @this.BeginInvoke(new Action(() =>
            {
                if (color == null)
                {
                    @this.AppendText(text);
                }
                else
                {
                    var colorB4 = @this.ForeColor;
                    @this.SelectionColor = (Color)color;
                    @this.AppendText(text);
                    @this.SelectionColor = colorB4;
                }
            }));
        }
    }
}