I've got this code in my App.xaml.cs:
protected override void OnStartup(StartupEventArgs e)
{
EventManager.RegisterClassHandler(typeof(TextBox), TextBox.TextChangedEvent, new RoutedEventHandler(TextBox_TextChangedEvent));
}
private void TextBox_TextChangedEvent(object sender, RoutedEventArgs e)
{
// Works
}
I would like to do something similar for the InitializedEvent.
Here's my failed attempt:
protected override void OnStartup(StartupEventArgs e)
{
EventManager.RegisterClassHandler(typeof(FrameworkElement), FrameworkElement.InitializedEvent, new EventHandler(FrameworkElement_InitializedEvent));
}
private void FrameworkElement_InitializedEvent(object sender, EventArgs e)
{
}
Is the InitializedEvent somewhere else?
Is this even possible?
I've tried using the LoadedEvent:
protected override void OnStartup(StartupEventArgs e)
{
EventManager.RegisterClassHandler(typeof(FrameworkElement), FrameworkElement.LoadedEvent, new RoutedEventHandler(FrameworkElement_LoadedEvent));
}
private void FrameworkElement_LoadedEvent(object sender, RoutedEventArgs e)
{
// Fires only for Windows
}
It only fired for Windows and not the controls inside the Windows. I did realize though; that when I added a loaded event to a Label that I had inside my Window; the global FrameworkElement_LoadedEvent
fired for that Label even though my normal loaded event (That I made for the Label specifically) was empty. I've also tried these:
EventManager.RegisterClassHandler(typeof(Button), Button.LoadedEvent, new RoutedEventHandler(Button_LoadedEvent));
EventManager.RegisterClassHandler(typeof(Grid), Grid.LoadedEvent, new RoutedEventHandler(Grid_LoadedEvent));
EventManager.RegisterClassHandler(typeof(DataGrid), DataGrid.LoadedEvent, new RoutedEventHandler(DataGrid_LoadedEvent));
But they don't fire unless I add another empty loaded event on those controls specifically.
My goal is to build up a sort of a time log of every control that becomes initialized.
How can I achieve this without adding loaded events on every single control I have?
(I have a lot)
Here you are!
public partial class App : Application
{
// ##############################################################################################################################
// Constructor
// ##############################################################################################################################
#region Constructor
static App()
{
// set MyInitialized=true for new windows (happens before Loaded)
EventManager.RegisterClassHandler(typeof(Window), FrameworkElement.SizeChangedEvent, new RoutedEventHandler(OnSizeChanged));
// our loaded handler
EventManager.RegisterClassHandler(typeof(UIElement), FrameworkElement.LoadedEvent, new RoutedEventHandler(OnLoaded), true);
EventManager.RegisterClassHandler(typeof(ContentElement), FrameworkContentElement.LoadedEvent, new RoutedEventHandler(OnLoaded), true);
}
private static void OnSizeChanged(object sender, RoutedEventArgs e)
{
//Console.WriteLine("SizeChanged {0}", sender);
SetMyInitialized((Window) sender, true);
}
private static void OnLoaded(object sender, RoutedEventArgs e)
{
Trace.WriteLine($"{DateTime.Now:O}: {sender} loaded");
}
#endregion
// ##############################################################################################################################
// MyInitialized
// ##############################################################################################################################
#region MyInitialized
public static void SetMyInitialized(UIElement element, bool value)
{
element.SetValue(MyInitializedProperty, value);
}
public static bool GetMyInitialized(UIElement element)
{
return (bool) element.GetValue(MyInitializedProperty);
}
public static readonly DependencyProperty MyInitializedProperty = DependencyProperty.RegisterAttached("MyInitialized", typeof (bool), typeof (App), new FrameworkPropertyMetadata(false, FrameworkPropertyMetadataOptions.Inherits, OnMyInitializedChanged));
private static void OnMyInitializedChanged(DependencyObject dpo, DependencyPropertyChangedEventArgs ev)
{
if ((bool)ev.NewValue)
{
// registering instance handler unbreaks class handlers
if (dpo is FrameworkElement element)
element.Loaded += _EmptyRoutedEventHandler;
if (dpo is FrameworkContentElement contentElement)
contentElement.Loaded += _EmptyRoutedEventHandler;
} else
{
throw new ArgumentException("Cannot set to false", ev.Property.Name);
}
//Console.WriteLine("MyInitialized {0} {1}=>{2}", dpo, ev.OldValue, ev.NewValue);
}
private static readonly RoutedEventHandler _EmptyRoutedEventHandler = delegate { };
#endregion
}
<Window x:Class="WpfApp3.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WpfApp3"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800"
d:DataContext="{d:DesignInstance local:MainWindow}">
<Grid>
<Border Background="Green" VerticalAlignment="Center" HorizontalAlignment="Center" Width="30" Height="20">
<TextBlock Background="Orange" Text="hello"></TextBlock>
</Border>
</Grid>
</Window>
Sample Console
output:
2018-07-31T14:20:52.6052225+02:00: WpfApp3.MainWindow loaded
2018-07-31T14:20:52.6112064+02:00: System.Windows.Controls.Border loaded
2018-07-31T14:20:52.6132008+02:00: System.Windows.Documents.AdornerDecorator loaded
2018-07-31T14:20:52.6141984+02:00: System.Windows.Controls.ContentPresenter loaded
2018-07-31T14:20:52.6141984+02:00: System.Windows.Controls.Grid loaded
2018-07-31T14:20:52.6151966+02:00: System.Windows.Controls.Border loaded
2018-07-31T14:20:52.6161935+02:00: System.Windows.Controls.TextBlock loaded
2018-07-31T14:20:52.6161935+02:00: System.Windows.Documents.AdornerLayer loaded
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