Backgroundworker won't report progress

Question

I have a background worker running a long database task. i want to show the progress bar while the task is running. Somehow the background worker won't report the progress of the task.

This is what i have:

BackgroundWorker _bgwLoadClients;

_bgwLoadClients = new BackgroundWorker();
_bgwLoadClients.WorkerReportsProgress = true;
_bgwLoadClients.DoWork += new DoWorkEventHandler(_bgwLoadClients_DoWork);
_bgwLoadClients.RunWorkerCompleted += new RunWorkerCompletedEventHandler(_bgwLoadClients_RunWorkerCompleted);
_bgwLoadClients.ProgressChanged += new ProgressChangedEventHandler(_bgwLoadClients_ProgressChanged);
_bgwLoadClients.RunWorkerAsync(parms);

private void _bgwLoadClients_DoWork(object sender, DoWorkEventArgs e)
{
    DataTable dt = getdate();
    e.Result = dt;
}

void _bgwLoadClients_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
    progressBar1.Value = e.ProgressPercentage;
}

I am doing this in WPF, but i guess it won't make a difference.

Thanks in advance

Solution 1

You need to break your DoWork method down into reportable progress and then call ReportProgress.

Take for example the following:

private void Something_DoWork(object sender, DoWorkEventArgs e) 
{
    // If possible, establish how much there is to do
    int totalSteps = EstablishWorkload();

    for ( int i=0; i<totalSteps; i++)
    {
        // Do something...

        // Report progress, hint: sender is your worker
        (sender as BackgroundWorker).ReportProgress((int)(100/totalSteps)*i, null);
    }

}

If your work can't be predetermined, try adding your own percentages:

private void Something_DoWork(object sender, DoWorkEventArgs e) 
{
    // some work

    (sender as BackgroundWorker).ReportProgress(25, null);

    // some work

    (sender as BackgroundWorker).ReportProgress(50, null);

    // some work

    (sender as BackgroundWorker).ReportProgress(60, null);

    // some work

    (sender as BackgroundWorker).ReportProgress(99, null);
}

Solution 2

Modify the WorkReportProgress property of the backgroundworker object to true either in the properties window or in code.

Solution 3

You need to call worker.ReportProgress(percentComplete) in your DoWork method. percentComplete should be computed based on the total work. For example:

for(int i =0; i != 100; i++) {
    // do something
    worker.ReportProgress(i);
}

Sometimes it is difficult to partition a job in several chunks to be possible to report the progress. Unfortunately the BackgroundWorker does not solve this, you have to do it yourself.

Solution 4

You have to manualy call ReportProgress() to raise the ProgressChanged event.

Solution 5

just report progress on dowork event

private void _bgwLoadClients_DoWork(object sender, DoWorkEventArgs e) {
    int progresValue0to100 = 75;
    (sender as System.ComponentModel.BackgroundWorker).ReportProgress(progresValue0to100);
    //do your jobs..
}

it works like this

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