Halting event routing with Handled

    

<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.vb

Imports System
Imports System.Windows
Imports System.Diagnostics

Namespace WpfApplication1
  Public Partial Class HaltingEvents
    Inherits System.Windows.Window

    Public Sub New()
      InitializeComponent()
    End Sub
    Private Sub ButtonDownCanvas(sender As Object, e As RoutedEventArgs)
      Debug.WriteLine("ButtonDownCanvas")
      e.Handled = True
    End Sub
    Private Sub PreviewMouseDownButton(sender As Object, e As RoutedEventArgs)
      Debug.WriteLine("PreviewMouseDownButton")
    End Sub

    Private Sub MouseDownButton(sender As Object, e As RoutedEventArgs)
      Debug.WriteLine("MouseDownButton")
    End Sub


    Private Sub PreviewMouseDownGrid(sender As Object, e As RoutedEventArgs)
      Debug.WriteLine("PreviewMouseDownGrid")
    End Sub

    Private Sub MouseDownGrid(sender As Object, e As RoutedEventArgs)
      Debug.WriteLine("MouseDownGrid")
    End Sub


    Private Sub PreviewMouseDownCanvas(sender As Object, e As RoutedEventArgs)
      Debug.WriteLine("PreviewMouseDownCanvas")
    End Sub


    Private Sub PreviewMouseDownEllipse(sender As Object, e As RoutedEventArgs)
      Debug.WriteLine("PreviewMouseDownEllipse")
    End Sub

    Private Sub MouseDownEllipse(sender As Object, e As RoutedEventArgs)
      Debug.WriteLine("MouseDownEllipse")
    End Sub
  End Class
End Namespace

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Halting event routing with Handled : Event « Windows Presentation Foundation « VB.Net

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