Check the mouse event source : Mouse « Windows Presentation Foundation « VB.Net Tutorial

1. VB.Net Tutorial
2. Windows Presentation Foundation
3. Mouse

<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MouseInput" Height="300" Width="300">
    <Grid>
      <Ellipse Fill="Blue" x:Name="myEllipse" />
    </Grid>
</Window>


//File:Window.xaml.vb
Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Data
Imports System.Windows.Documents
Imports System.Windows.Input
Imports System.Windows.Media
Imports System.Windows.Media.Imaging
Imports System.Windows.Shapes
Imports System.Diagnostics


Namespace WpfApplication1
  Public Partial Class Window1
    Inherits System.Windows.Window
    Public Sub New()
      InitializeComponent()
    End Sub
    Private Sub StartSlowWork()
      Mouse.OverrideCursor = Cursors.AppStarting
    End Sub

    Private Sub SlowWorkCompleted()
      Mouse.OverrideCursor = Nothing
    End Sub

    Protected Overrides Sub OnMouseDown(e As MouseButtonEventArgs)
      MyBase.OnMouseDown(e)
      If e.Source Is myEllipse Then
        StartSlowWork()
      End If
    End Sub

    Protected Overrides Sub OnMouseUp(e As MouseButtonEventArgs)
      MyBase.OnMouseUp(e)
      SlowWorkCompleted()
    End Sub

  End Class
End Namespace

16.91.Mouse
	16.91.1.	MouseDown action on Line
	16.91.2.	Hit Result Behavior
	16.91.3.	Button PreviewMouseLeftButtonDown action and MouseLeftButtonDown action
	16.91.4.	Grid MouseLeftButtonDown action and PreviewMouseLeftButtonDown action
	16.91.5.	Detect whether the mouse button is pressed or released using the MouseButtonState property.
	16.91.6.	Handler MouseLeftButtonDown and MouseLeftButtonUp events
	16.91.7.	Make an object follow the mouse pointer as it moves on the screen.
	16.91.8.	Use Mouse.AddPreviewMouseDownHandler(myEllipse, PreviewMouseDownEllipse);
	16.91.9.	Use Mouse.AddMouseDownHandler(myEllipse, MouseDownEllipse);
	16.91.10.	Use Mouse.PreviewMouseDown /Mouse.MouseDown Attribute from Grid element
	16.91.11.	A line which monitors the mouse entering its area
	16.91.12.	Mouse Position and TranslateTransform
	16.91.13.	Mouse Position
	16.91.14.	Get mouse position with Mouse.GetPosition
	16.91.15.	Replease mouse with Mouse.Capture(null)
	16.91.16.	Retrieving the mouse position relative to controls on a Window
	16.91.17.	Mouse cursor override and clear
	16.91.18.	Check the mouse event source
	16.91.19.	Use the Mouse Wheel action methods that are defined by the IScrollInfo interface
	16.91.20.	Change control background in mouse enter and leave
	16.91.21.	Use EventSetter to add mouse event handler
	16.91.22.	Mouse.LostMouseCaptureEvent
	16.91.23.	Use Mouse.Capture to let a Control capture an event
	16.91.24.	Point Hit Test