Question

Currently I have a background thread whose doWork calls a function similar to below.

private void ThreadForAnalyzingReqFile_DoWork(object sender, DoWorkEventArgs e) 
{
    AnotherClass.AVeryLongTimedFunction();
}

Now, the code shall wait until AVeryLongTimedFunction() in AnotherClass finishes (that may take about 1-2 minutes) While this happens, how do I know exactly what’s happening? Is there any way I can be notified that function (in another class) finishes?

This thread is in my MainWindow class of WPF. I am using Visual Studio 2010.

Answer 1

There are many ways to do this. Two easy options:

(1) Create an event in your UI class such as UpdateProgress, and notify that event at meaningful intervals

Example:

    private void ThreadForAnalyzingReqFile_DoWork(object sender, DoWorkEventArgs e)
    {
        AnotherClass processor = new AnotherClass();
        processor.ProgressUpdate += new AnotherClass.ReallyLongProcessProgressHandler(this.Processor_ProgressUpdate);
        processor.AVeryLongTimedFunction();
    }

    private void Processor_ProgressUpdate(double percentComplete)
    {

        this.progressBar1.Invoke(new Action(delegate()
        {
            this.progressBar1.Value = (int)(100d*percentComplete); // Do all the ui thread updates here
        }));
    }

And in “AnotherClass”

public partial class AnotherClass
{
    public delegate void ReallyLongProcessProgressHandler(double percentComplete);

    public event ReallyLongProcessProgressHandler ProgressUpdate;

    private void UpdateProgress(double percent)
    {
        if (this.ProgressUpdate != null)
        {
            this.ProgressUpdate(percent);
        }
    }

    public void AVeryLongTimedFunction()
    {
        //Do something AWESOME
        List<Item> items = GetItemsToProcessFromSomewhere();
        for (int i = 0; i < items.Count; i++)
        {
            if (i % 50)
            {
               this.UpdateProgress(((double)i) / ((double)items.Count)
            }
            //Process item
        }
    }
}

(2) Create a progress percentage field on AnotherClass. Occasionally interrogate this in your UI on a timer.