c# WPF 如何在 xaml window 加载时显示我的进度条？

Question

i am trying to display my Progress bar while my WPF window is loading. I succeeded to fill the progressbar but it's not showing Refer to the screenshots to see what i mean showingProgressBar but when the windows has loaded completly , it's showing when every components of the window is loaded. It's doing the right behavior i want when I put some MessageBox at the end of every method to load components like this screenshot and this screenshot , so my question is How to show my progressbar while the xaml window is loading? any help would be appreciated.

Thanks in advance

   private void DoWorkButton_Click(object sender, RoutedEventArgs e)
       {

             testProgressBar.Visibility = Visibility.Visible;
              ProgressTextblock.Visibility = Visibility.Visible;
               BackgroundWorker worker = new BackgroundWorker();
               worker.RunWorkerCompleted += worker_RunWorkerCompleted;
                worker.WorkerReportsProgress = true;
                worker.DoWork += worker_doWork;
                worker.ProgressChanged += worker_ProgressChanged;
                 worker.RunWorkerAsync();
    }

    private void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
    {
        testProgressBar.Value = e.ProgressPercentage;
        ProgressTextblock.Text = (string)e.UserState;
    }

    private void worker_doWork(object sender, DoWorkEventArgs e)
    {
        var worker = sender as BackgroundWorker;
        worker.ReportProgress(0, String.Format("Chargement des composants de la fenetre"));



    }

    private void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        MessageBox.Show("Fenetre chargée normalement");

    }

I fill the Progress bar like this in every method which is called to load the the window

Answer 1

It's how you've set the order, I think ordering it like this should solve it:

 private void DoWorkButton_Click(object sender, RoutedEventArgs e)
   {
         testProgressBar.Visibility = Visibility.Visible;
         ProgressTextblock.Visibility = Visibility.Visible;
         BackgroundWorker worker = new BackgroundWorker();
         worker.WorkerReportsProgress = true; 
         worker.DoWork += worker_doWork;                         
         worker.ProgressChanged += worker_ProgressChanged;
         worker.RunWorkerCompleted += worker_RunWorkerCompleted;
         worker.RunWorkerAsync();
}