Question

Here is my method that starts a process:

public class Tshark
{
    public int _interfaceNumber;
    public string _pcapPath;
    Process _tsharkProcess;
    public int _packetsCount;
    public string _packet;
    public string _tsharkPath = @"C:\Program Files\Wireshark\tshark.exe";
    public delegate void dlgPackProgress(int progress);
    public event dlgPackProgress evePacketProgress;

    public Tshark(int interfaceNumber, string pcapPath)
    {
        _interfaceNumber = interfaceNumber;
        _pcapPath = pcapPath;
    }

    public void startTheCapture()
    {
        try
        {
            _tsharkProcess = new Process();
            _tsharkProcess.StartInfo.FileName = @"C:\Program Files\Wireshark\tshark.exe";
            _tsharkProcess.StartInfo.Arguments = string.Format("-i " + _interfaceNumber);
            _tsharkProcess.OutputDataReceived += new DataReceivedEventHandler(process_OutputDataReceived);
            _tsharkProcess.StartInfo.RedirectStandardOutput = true;
            _tsharkProcess.StartInfo.UseShellExecute = false;
            _tsharkProcess.StartInfo.CreateNoWindow = true;
            _tsharkProcess.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
            _tsharkProcess.Start();
            StreamReader myStreamReader = _tsharkProcess.StandardOutput;

            while (!myStreamReader.EndOfStream)
            {
                _packet = myStreamReader.ReadLine();
                OnPacketProgress(_packetsCount++);
            }

            _tsharkProcess.WaitForExit();
        }
        catch (Exception e)
        {

        }
    }

    private void OnPacketProgress(int packet)
    {
        var handler = evePacketProgress;
        if (handler != null)
        {
            handler(packet);
        }
    }

    public void killProcess()
    {
        foreach (Process prc in System.Diagnostics.Process.GetProcessesByName("tshark"))
            {
                prc.Kill();
                prc.WaitForExit();
            }                 
    }

    private void process_OutputDataReceived(object sender, DataReceivedEventArgs arg)
    {
        string srt = arg.Data; //arg.Data contains the output data from the process...            
    }
}

The method startTheCapture() is invoked from the main form :

private void btnStartCapture_Click(object sender, EventArgs e)
{
    BackgroundWorker bgWorker = new BackgroundWorker();
    bgWorker.WorkerReportsProgress = true;
    bgWorker.ProgressChanged += new ProgressChangedEventHandler(bgWSniffer_ProgressChanged);
    bgWorker.DoWork += new DoWorkEventHandler(
        (s3, e3) =>
        {
            tshark = new Tshark(2, pcapFilePathSniffer);
            tshark.startTheCapture();

            tshark.evePacketProgress += new Tshark.dlgPackProgress(
                (packet) =>
                {
                    bgWorker.ReportProgress(packet, tshark);
                });
        });

    bgWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(
        (s3, e3) =>
        {

        });

    bgWorker.RunWorkerAsync();

}

Now this is from the main form too, I have written ProgressChanged which is supposed to update my gui but my problem is that this is not working and I cannot figure why.

private void bgWSniffer_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
    tshark = e.UserState as Tshark;
    listBoxPacketsSnifferTab.Text += tshark._packet;
    lblPacketsReceived2.Text = tshark._packetsCount.ToString("#,##0");
}

Answer 1

in your DoWorkEventHandler, you call tshark.StartTheCapture() before you hookup evePacketProgress event handler.

The startTheCapture method blocks until the wireshark process exits, so any progress events captured while it’s running will be “ignored” in OnPacketProgress because there is no event subscriber (handler == null).

change it to this:

bgWorker.DoWork += new DoWorkEventHandler(
    (s3, e3) =>
    {
        tshark = new Tshark(2, pcapFilePathSniffer);

        //hookup event handler before executing method
        tshark.evePacketProgress += new Tshark.dlgPackProgress(
            (packet) =>
            {
                bgWorker.ReportProgress(packet, tshark);
            });

        tshark.startTheCapture();


    });