When to start the WPF Progress Bar - wpf

Question

I want my app to show a running progress bar while doing some components checking. However, due to my lack of knowledge in Desktop app programming and WPF, I cannot find suitable place for it.
I tried to show the incrementing the progress Bar during the Window_Loaded(), ContentRendered() but with no luck.
Instead of showing the progressBar increases, it just show the final state of the progress Bar.
Here is the code
public partial class Loading : Window
{
public Loading()
{
InitializeComponent();
SetProgressBar();
this.Show();
CheckComponents();
}
private void CheckComponents()
{
System.Threading.Thread.Sleep(3000);
CheckProductionDBConnection();
pgrsBar.Value = 30;
System.Threading.Thread.Sleep(3000);
CheckInternalDBConnection();
pgrsBar.Value = 60;
System.Threading.Thread.Sleep(3000);
CheckProductionPlanning();
pgrsBar.Value = 90;
//MainWindow mainWindow = new MainWindow();
//mainWindow.Show();
}
private void SetProgressBar()
{
pgrsBar.Minimum = 0;
pgrsBar.Maximum = 100;
pgrsBar.Value = 0;
}
//more code down here...
Where should I put the CheckComponents() method?

Answer 1

You could put this code in an event handler subscribed to the Activated event. The one catch with this is that the Activated event is fired every time the window receives focus after having lost it. To get around this, the first thing you can do in your event handler is unsubscribe from the Activated event so that your code is executed only the first time the window is activated.
You also need to offload this work to a worker thread if you don't want the delay to block the main thread. If you do that, you'll have to invoke your calls to update the progess bar's value.
Here's some sample code to get you started:
public Loader()
{
InitializeComponent();
SetProgressBar();
this.Activated += OnActivatedFirstTime;
}
private void OnActivatedFirstTime(object sender, EventArgs e)
{
this.Activated -= this.OnActivatedFirstTime;
ThreadPool.QueueUserWorkItem(x =>
{
System.Threading.Thread.Sleep(3000);
CheckProductionDBConnection();
this.Dispatcher.BeginInvoke(new Action(() => pgrsBar.Value = 30));
System.Threading.Thread.Sleep(3000);
CheckInternalDBConnection();
this.Dispatcher.BeginInvoke(new Action(() => pgrsBar.Value = 60));
System.Threading.Thread.Sleep(3000);
CheckProductionPlanning();
this.Dispatcher.BeginInvoke(new Action(() => pgrsBar.Value = 90));
});
}
private void SetProgressBar()
{
pgrsBar.Minimum = 0;
pgrsBar.Maximum = 100;
pgrsBar.Value = 0;
}