Halting event routing with Handled : Event « Windows Presentation Foundation « C# / CSharp Tutorial






  1. C# / CSharp Tutorial
  2. Windows Presentation Foundation
  3. Event
<Window x:Class="WpfApplication1.HaltingEvents"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Halting Events" Height="300" Width="300">
  <Grid HorizontalAlignment="Center" VerticalAlignment="Center">
    <Button PreviewMouseDown="PreviewMouseDownButton"
    MouseDown="MouseDownButton">

      <Grid PreviewMouseDown="PreviewMouseDownGrid"
            MouseDown="MouseDownGrid">
        <Grid.ColumnDefinitions>
          <ColumnDefinition />
          <ColumnDefinition />
        </Grid.ColumnDefinitions>

        <Canvas PreviewMouseDown="PreviewMouseDownCanvas"
                MouseDown="ButtonDownCanvas"
                Width="20" Height="18" VerticalAlignment="Center">

          <Ellipse PreviewMouseDown="PreviewMouseDownEllipse"
                   MouseDown="MouseDownEllipse"
                   x:Name="myEllipse"
                   Canvas.Left="1" Canvas.Top="1" Width="16" Height="16"
                   Fill="Yellow" Stroke="Black" />

          <Ellipse Canvas.Left="4.5" Canvas.Top="5" Width="2.5" Height="3"
                   Fill="Black" />
          <Ellipse Canvas.Left="11" Canvas.Top="5" Width="2.5" Height="3"
                   Fill="Black" />
          <Path Data="M 5,10 A 3,3 0 0 0 13,10" Stroke="Black" />
        </Canvas>

        <TextBlock Grid.Column="1">Click!</TextBlock>
      </Grid>
    </Button>
  </Grid>
</Window>



//File:Window.xaml.cs

using System;
using System.Windows;
using System.Diagnostics;

namespace WpfApplication1
{
    public partial class HaltingEvents : System.Windows.Window
    {

        public HaltingEvents()
        {
            InitializeComponent();
        }
        void ButtonDownCanvas(object sender, RoutedEventArgs e)
        {
            Debug.WriteLine("ButtonDownCanvas");
            e.Handled = true;
        }
        void PreviewMouseDownButton(object sender, RoutedEventArgs e)
        { Debug.WriteLine("PreviewMouseDownButton"); }

        void MouseDownButton(object sender, RoutedEventArgs e)
        { Debug.WriteLine("MouseDownButton"); }


        void PreviewMouseDownGrid(
          object sender, RoutedEventArgs e)
        { Debug.WriteLine("PreviewMouseDownGrid"); }

        void MouseDownGrid(object sender, RoutedEventArgs e)
        { Debug.WriteLine("MouseDownGrid"); }


        void PreviewMouseDownCanvas(object sender, RoutedEventArgs e)
        { Debug.WriteLine("PreviewMouseDownCanvas"); }


        void PreviewMouseDownEllipse(object sender, RoutedEventArgs e)
        { Debug.WriteLine("PreviewMouseDownEllipse"); }

        void MouseDownEllipse(object sender, RoutedEventArgs e)
        { Debug.WriteLine("MouseDownEllipse"); }
    }
}
WPF Halting Event Routing With Handled




24.119.Event
24.119.1.Cast event sender to a controlCast event sender to a control
24.119.2.Press F1 to get helpPress F1 to get help
24.119.3.Raise the PropertyChanged eventRaise the PropertyChanged event
24.119.4.Get the event sender nameGet the event sender name
24.119.5.Use Ellipse event delegateUse Ellipse event delegate
24.119.6.Halting event routing with HandledHalting event routing with Handled
24.119.7.Use Ellipse.AddHandler to add handler to Ellipse objectsUse Ellipse.AddHandler to add handler to Ellipse objects
24.119.8.Get event sender from eventGet event sender from event
24.119.9.Handle the ContentRendered eventHandle the ContentRendered event
24.119.10.Find source element of an element in event handler by casintFind source element of an element in event handler by casint
24.119.11.Add an event handler to an element using codeAdd an event handler to an element using code
24.119.12.Handles the Click event on the UniformGridHandles the Click event on the UniformGrid
24.119.13.Mark the text control as being changed to prevent any text content or selection changed eventsMark the text control as being changed to prevent any text content or selection changed events
24.119.14.Check handler event senderCheck handler event sender
24.119.15.Generate Click Events Repeatedly While a Button Is ClickedGenerate Click Events Repeatedly While a Button Is Clicked
24.119.16.Raise the ScrollChanged event of a ScrollViewerRaise the ScrollChanged event of a ScrollViewer
24.119.17.Event firing sequenceEvent firing sequence
24.119.18.ToolBar and event handlerToolBar and event handler
24.119.19.Cancel event by setting CanExecute and Handled to falseCancel event by setting CanExecute and Handled to false
24.119.20.Activated and Deactivated events monitors the activation status of an application.Activated and Deactivated events monitors the activation status of an application.
24.119.21.Event sender, event source and event original sourceEvent sender, event source and event original source