Using a BackgroundWorker to complete a task.

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The following example demonstrates the use of a BackgroundWorker to update a WinForms ProgressBar. The backgroundWorker will update the value of the progress bar without blocking the UI thread, thus showing a reactive UI while work is done in the background.

namespace BgWorkerExample
    public partial class Form1 : Form

	    // a new instance of a backgroundWorker is created.
	    BackgroundWorker bgWorker = new BackgroundWorker();
	    public Form1()
	        prgProgressBar.Step = 1;
	        //this assigns event handlers for the backgroundWorker
	        bgWorker.DoWork += bgWorker_DoWork;
	        bgWorker.RunWorkerCompleted += bgWorker_WorkComplete;
	        //tell the backgroundWorker to raise the "DoWork" event, thus starting it.
	        //Check to make sure the background worker is not already running.
	    private void bgWorker_DoWork(object sender, DoWorkEventArgs e)
	        //this is the method that the backgroundworker will perform on in the background thread.
	        /* One thing to note! A try catch is not necessary as any exceptions will terminate the backgroundWorker and report 
	          the error to the "RunWorkerCompleted" event */
	    private void bgWorker_WorkComplete(object sender, RunWorkerCompletedEventArgs e)
	        //e.Error will contain any exceptions caught by the backgroundWorker
	        if (e.Error != null)
	            MessageBox.Show("Task Complete!");
	            prgProgressBar.Value = 0;
	    // example method to perform a "long" running task.
	    private void CountToY()
	        int x = 0;
	        int maxProgress = 100;
	        prgProgressBar.Maximum = maxProgress;
	        while (x < maxProgress)
	            Invoke(new Action(() => { prgProgressBar.PerformStep(); }));
	            x += 1;

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