Is there a “All Children loaded” event in WPF

Question

I am listening for the loaded event of a Page. That event fires first and then all the children fire their load event. I need an event that fires when ALL the children have

Answer 1

You can also use the event: ContentRendered.

http://msdn.microsoft.com/en-us/library/ms748948.aspx#Window_Lifetime_Events

Answer 2

I ended up doing something along these lines.. your milage may vary.

void WaitForTheKids(Action OnLoaded)
{
  // After your children have been added just wait for the Loaded
  // event to fire for all of them, then call the OnLoaded delegate

  foreach (ContentControl child in Canvas.Children)
  {
    child.Tag = OnLoaded; // Called after children have loaded
    child.Loaded += new RoutedEventHandler(child_Loaded);
  }
}
internal void child_Loaded(object sender, RoutedEventArgs e)
{
  var cc = sender as ContentControl;
  cc.Loaded -= new RoutedEventHandler(child_Loaded);

  foreach (ContentControl ctl in Canvas.Children)
  {
    if (!ctl.IsLoaded)
    {
      return;
    }
  }
  ((Action)cc.Tag)();
}

Answer 3

Loaded is the event that fires after all children have been Initialized. There is no AfterLoad event as far as I know. If you can, move the children's logic to the Initialized event, and then Loaded will occur after they have all been initialized.

See MSDN - Object Lifetime Events.

Answer 4

WPF cant provide that kind of an event since most of the time Data is determining whther to load a particular child to the VisualTree or not (for example UI elements inside a DataTemplate)

So if you can explain your scenario little more clearly we can find a solution specific to that.

Answer 5

One of the options (when content rendered):

this.LayoutUpdated += OnLayoutUpdated;

private void OnLayoutUpdated(object sender, EventArgs e)
            {
                if (!isInitialized && this.ActualWidth != 0 && this.ActualHeight != 0)
                {
                    isInitialized = true;
                    // Logic here
                }
            };

Answer 6

I had the same problem. @configurator is right, if you are having this problem then I believe it is because you have a problem with your child elements. In my case the child elements where a custom user control. I was initializing them incorrectly. I fixed the user control and everything worked great