Waiting Screen for WPF window Loading

Question

I am navigating from some window window1 to Mainwindow

In my MainWindow_loaded Method i have too much computation so when i navigate to main window windows goes white untill all computation finished and window loaded

I tried in MainWindow

 private void MainWindow_Loaded_1(object sender, RoutedEventArgs e)

 BackgroundWorker worker = new BackgroundWorker();

       worker.DoWork += (o, ea) =>
        {
             do large computation
          };

          worker.RunWorkerCompleted += (o, ea) =>
           {

               _busy.IsBusy = false;
          };
         _busy.IsBusy = true;
         worker.RunWorkerAsync();

}

But problem is that it navigates to Mainwindow without computation of necessary data in loaded event handler and doesnt even show waiting bar in UI ? ? Is it possible to show waiting bar and all computation of data in MainWindow_Loaded?

I have used ExtendedWpfToolkit for _busy which is busy indicator

Answer 1

You can subscribe your background worker to report progress.

worker.WorkerReportsProgress = true;

And now you can have this progress report be triggered by an event you subscribe to.

worker.ProgressChanged += new ProgressChangedEventHandler(worker_ProgressChanged);

In doing so, you can create a progress bar than can update itself based on this worker_ProgressChanged event, triggered by your computation.

It appears you've already figured out IsBusy, so you can have your progress bar show only when this is true.

Answer 2

You can use BusyIndicator control. It is part of the Extended WPF ToolKit.

I have created a sample app using it. Below is screen shot of the app which displays the loop count.

Here is a tutorial on how to use it.

Sample code.

Note: You need to download the tool kit and add a reference to Xceed.Wpf.Toolkit.dll in your project.

XAML code:

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:WPFTool="clr-namespace:Xceed.Wpf.Toolkit;assembly=Xceed.Wpf.Toolkit"
        Title="MainWindow" Height="200" Width="300" Loaded="Window_Loaded">
    <WPFTool:BusyIndicator Name="BusyIndicator">
        <Grid>
        </Grid>
    </WPFTool:BusyIndicator>
</Window>

CodeBehind:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.ComponentModel;
using System.Threading;

namespace WpfApplication1
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            BusyIndicator.IsBusy = true;
            BusyIndicator.BusyContent = "Initializing...";
            BackgroundWorker worker = new BackgroundWorker();
            worker.DoWork += (o, a) =>
                {
                    for (int index = 0; index < 5; index++)
                    {
                        Dispatcher.Invoke(new Action(() =>
                        {
                            BusyIndicator.BusyContent = "Loop : " + index;
                        }), null);
                        Thread.Sleep(new TimeSpan(0, 0, 1));
                    }
                };
            worker.RunWorkerCompleted += (o, a) =>
                {
                    BusyIndicator.IsBusy = false;
                };
            worker.RunWorkerAsync();
        }

    }
}