DispatcherTimer and EventHandler : Event « Windows Presentation Foundation « VB.Net Tutorial






  1. VB.Net Tutorial
  2. Windows Presentation Foundation
  3. Event
<Window x:Class="Holding.Window2"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="FillingExample" Height="300" Width="300">
  <Canvas>
    <Ellipse Name="myEllipse" Height="100" Fill="Red">
      <Ellipse.Triggers>
        <EventTrigger RoutedEvent="Ellipse.Loaded">
          <BeginStoryboard>
            <Storyboard>
              <DoubleAnimation BeginTime="0:0:2" Duration="0:0:5"
                  Storyboard.TargetProperty="(Ellipse.Width)"
                  From="10" To="300" FillBehavior="Stop" />

            </Storyboard>
          </BeginStoryboard>
        </EventTrigger>
      </Ellipse.Triggers>
    </Ellipse>
  </Canvas>
</Window>
//File:Window.xaml.vb

Imports System
Imports System.Windows
Imports System.Windows.Threading
Imports System.Diagnostics

Namespace Holding
  Public Partial Class Window2
    Inherits Window
    Private t As New DispatcherTimer()
    Private start As DateTime
    Public Sub New()
      InitializeComponent()
      AddHandler t.Tick, New EventHandler(AddressOf OnTimerTick)
      t.Interval = TimeSpan.FromSeconds(0.5)
      t.Start()
      start = DateTime.Now
    End Sub
    Private Sub OnTimerTick(sender As Object, e As EventArgs)
      Dim elapsedTime As TimeSpan = DateTime.Now - start
      Debug.WriteLine((elapsedTime.ToString() & ": ") + myEllipse.Width)
    End Sub
  End Class
End Namespace
WPF Dispatcher Timer And Event Handler




16.87.Event
16.87.1.Get event sender from eventGet event sender from event
16.87.2.Handle the ContentRendered eventHandle the ContentRendered event
16.87.3.Find source element of an element in event handler by castingFind source element of an element in event handler by casting
16.87.4.Add an event handler to an element using codeAdd an event handler to an element using code
16.87.5.Halting event routing with HandledHalting event routing with Handled
16.87.6.Security ExceptionSecurity Exception
16.87.7.Throw Handled ExceptionThrow Handled Exception
16.87.8.Check handler event senderCheck handler event sender
16.87.9.Do event based on button nameDo event based on button name
16.87.10.Add event handler to StackPanel in StackPanel resourceAdd event handler to StackPanel in StackPanel resource
16.87.11.Add a PropertyChangedValueCallback to Any Dependency PropertyAdd a PropertyChangedValueCallback to Any Dependency Property
16.87.12.Handle a Button Click with Shared button click handlerHandle a Button Click with Shared button click handler
16.87.13.DispatcherTimer and EventHandlerDispatcherTimer and EventHandler
16.87.14.Thumb DragStarted and DragCompleted event handlerThumb DragStarted and DragCompleted event handler
16.87.15.Set interval and event handler for DispatcherTimerSet interval and event handler for DispatcherTimer
16.87.16.Get the event sender nameGet the event sender name
16.87.17.Event firing sequenceEvent firing sequence
16.87.18.Cancel event by setting CanExecute and Handled to falseCancel event by setting CanExecute and Handled to false
16.87.19.Event sender, event source and event original sourceEvent sender, event source and event original source
16.87.20.Cast event sender to a controlCast event sender to a control
16.87.21.Fire an event when an element gains and loses focus.Fire an event when an element gains and loses focus.