Question

hey i am new to c# plz help.
i am writing a program that sorts data in a file and it is a time consuming process so i thought that i should run it in a separate thread and since it has alot of step so i made a new class for it. the problem is that i want to show the progress in the main GUI and i know for that i have to use Invoke function but the problem is that the form control variables are not accessible it this class. what should i do ??????

sample code:

public class Sorter
{
    private string _path;
    public Sorter(string path)
    {
        _path = path;
    }

    public void StartSort()
    {
        try
        {
                 processFiles(_path, "h4x0r"); // Just kidding
        }
        catch (Exception e)
        {
            MessageBox.Show("Error: " + e.ToString(), "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
    }

    private void processFiles(string Dir, string[] key)
    {
        /* sorting program */

    }

and it is used as

    public partial class Form1 : Form
    {
        Sorter sort;
        public Form1()
        {
            InitializeComponent();
        }

        private void browseBtn_Click(object sender, EventArgs e)
        {
            if (folderBrowserDialog1.ShowDialog() == DialogResult.OK)
                textBox1.Text = folderBrowserDialog1.SelectedPath;
        }

        private void startBtn_Click(object sender, EventArgs e)
        {
            if (startBtn.Text == "Start Sorting")
            {
   Thread worker = new Thread(new ThreadStart(delegate() {
                sort = new Sorter(textBox1.Text);
                sort.StartSort(); })); 
                worker.start();
            }
            else
                MessageBox.Show("Cancel");//TODO: add cancelling code here
        }
    }

plz help..

Answer 1

Add an Event to your class that is doing the multi-threaded work, that triggers when the progress changes. Have your form subscribe to this event and update the progress bar.

Note ProgressEventArgs is a little class that inherits EventArgs and has an Integer for the progress.

// delegate to update progress
public delegate void ProgressChangedEventHandler(Object sender, ProgressEventArgs e);

// Event added to your worker class.
public event ProgressChangedEventHandler ProgressUpdateEvent

// Method to raise the event
public void UpdateProgress(object sender, ProgressEventArgs e)
{
   ProgressChangedEventHandler handler;
   lock (progressUpdateEventLock)
   {
      handler = progressUpdateEvent;
   }

   if (handler != null)
      handler(sender, e);
}