How to wait until BackgroundWorker finish all calls

Question

I have Add button click event how add file:

private void btnAddfiles_Click(object sender, EventArgs e)
{
    if (openFileDialog1.ShowDialog() == Sys         


        

Answer 1

I just had the same problem, this worked for me.

 private void Worker_DoWork(object sender, EventArgs e)
    {
        if (Worker.IsBusy == false) { //...Finished execution }
    }

Answer 2

To prevent UI freezing, you can do this:

while (BackgroundWorker.IsBusy()) {
    Application.DoEvents();
}

I go this from the msdn docs, here

Answer 3

Most easy way is to keep a counter.

private int numWorkers = 0;

Then increment it as you start each background worker.

using (stream)
{
    Interlocked.Increment(ref numWorkers);
    StartBackgroundFileChecker(file);
}

Assign Same method as event completed to each background worker.

backgroundWorker.RunWorkerCompleted += myCommonCompletedHandler;

Decrement counter in completed event.

public void myCommonCompletedHandler(object sender, RunWorkerCompletedEventArgs e)
{
    if(Interlocked.Decrement(ref numWorkers) == 0) 
    {
      // all complete
    }
}

Answer 4

You may use this approch with only one BackgroundWorker.

BackgroundWorker backgroundWorker;

private void btnAddfiles_Click(object sender, EventArgs e)
{
    if (openFileDialog1.ShowDialog() == System.Windows.Forms.DialogResult.OK)
    {
        backgroundWorker = new BackgroundWorker();
        backgroundWorker.WorkerReportsProgress = true;
        backgroundWorker.DoWork +=
        (s3, e3) =>
        {
            StartBackgroundFileChecker(openFileDialog1.FileNames);   
        };

        backgroundWorker.ProgressChanged +=
        (s3, e3) =>
        {
            //example:
            this.progressBar1.Value = e.ProgressPercentage;
        };

        backgroundWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(
        (s3, e3) =>
        {
            ///End Here!!
        });

        backgroundWorker.RunWorkerAsync();
    }
}
private void StartBackgroundFileChecker(string[] files)
{
    for (int i = 0; i < files.Length; i++)
    {
        string file = files[i];
        System.IO.Stream stream;
        try
        {
            if ((stream = openFileDialog1.OpenFile()) != null)
            {
                using (stream)
                {
                    ListboxFile listboxFile = new ListboxFile();
                    listboxFile.OnFileAddEvent += listboxFile_OnFileAddEvent;
                    //Other things...
                }
            }
        }

        catch (Exception ex)
        {
            MessageBox.Show("Error: Could not read file from disk. Original error: " + ex.Message);
        }
        backgroundWorker.ReportProgress((i+1) * 100.0/files.Length, file);
    }
}