C#, WPF, Updating the gui without backgroundworkers

Question

I have a program that takes 10-20 seconds to start. I need to show a window with a progress bar when the program starts up. I know BackgroundWorker\'s are the correct way to do

Answer 1

If you don't want the background worker you need to adjust your code, to do the long task in the new thread.

using System;
using System.Threading;
using System.Windows;

namespace WpfApplication1
{
  public partial class Window1 : Window
  {
      public Window1()
      {
          InitializeComponent();

          Thread t = new Thread(DoSomeLongTask);
          t.Start();

          // switch this with the DoSomeLongTask, so the long task is
          // on the new thread and the UI thread is free.
          ShowLoadingWindow();
    }
  }
}

If you want to then update a progress bar from your "DoSomeLongTask" method then you'll need to ensure that you call invoke. For example:

delegate void ProgressDelegate(int Progress);  
private void UpdateProgress( int  Progress)  
{  
   if (!progressBar1.Dispatcher.CheckAccess())  
   {  
     progressBar1.Value = Progress;  
   }  
   else  
   {  
     ProgressDelegate progressD = new ProgressDelegate(UpdateProgress);  
     progressBar1.Dispatcher.Invoke(progressD, new object[] { Progress });  
   }  
}