Question

I have a Winforms application that schedules some work using a service. The service has a callback that updates the database with the work proceedings.

Now let’s say I schedule x work items. After the x work items are all completed, I want to generate an HTML report about the work statistics. I think the only way I can check the work completion of all items is to see their completion statuses in the database.

Can someone tell me how and when I can generate the HTML report? I think I can use a thread to poll the db to see if all work completed and inform UI to generate the report, but don’t know how to implement that.

Answer 1

You can use BackgroundWorker component for waiting async task completed. It’s easy.
First – drag BackgroundWorker from Toolbox to your form.

Second – when you start processing (e.g. on button click event) add following code:

private void button_Click(object sender, EventArgs e)
{
    backgroundWorker1.DoWork += backgroundWorker1_DoWork;    
    backgroundWorker1.RunWorkerCompleted += backgroundWorker1_RunWorkerCompleted;
    backgroundWorker1.RunWorkerAsync();
}

Next – add to DoWork event handler code that starts processing and polling database:

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
    // schedule some work
    // poll database
}

And last – add RunWorkerCompleted handler, which will run just after DoWork completed (i.e. all tasks updated their state in database):

private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
    // generate report
}

Thats it. Btw BackgroundWorker could report progress during polling database. Little searching will help you how to do that 🙂