Hit Result Behavior : Mouse « Windows Presentation Foundation « VB.Net Tutorial

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

<Window x:Class="WpfApplication1.HitTestExample"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  Title="WpfApplication1" Height="300" Width="300">


  <Canvas x:Name="canvas1"
    MouseLeftButtonDown="OnMouseLeftButtonDown">
    <Rectangle Canvas.Left="20" Canvas.Top="20" Width="100"
      Height="60" Stroke="Black" Fill="LightBlue" Opacity="0.7" />

    <Rectangle Canvas.Left="70" Canvas.Top="50" Width="100"
      Height="60" Stroke="Black" Fill="LightBlue" Opacity="0.7" />


    <Rectangle Canvas.Left="150" Canvas.Top="80" Width="100"
      Height="60" Stroke="Black" Fill="LightBlue" Opacity="0.7" />


    <Rectangle Canvas.Left="20" Canvas.Top="100" Width="50"
      Height="50" Stroke="Black" Fill="LightBlue" Opacity="0.7" />


    <Rectangle Canvas.Left="40" Canvas.Top="60" Width="50"
      Height="50" Stroke="Black" Fill="LightBlue" Opacity="0.7" />


    <Rectangle Canvas.Left="30" Canvas.Top="130" Width="50"
      Height="50" Stroke="Black" Fill="LightBlue" Opacity="0.7" />


  </Canvas>
</Window>

//File:Window.xaml.vb
Imports System
Imports System.Collections.Generic
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Input
Imports System.Windows.Media
Imports System.Windows.Shapes


Namespace WpfApplication1
  Public Partial Class HitTestExample
    Inherits Window
    Private hitList As New List(Of Rectangle)()
    Private hitArea As New EllipseGeometry()
    Public Sub New()
      InitializeComponent()
    End Sub
    Private Overloads Sub OnMouseLeftButtonDown(sender As Object, e As MouseButtonEventArgs)
      For Each rect As Rectangle In canvas1.Children
        rect.Fill = Brushes.Red
      Next

      Dim pt As Point = e.GetPosition(canvas1)
      hitArea = New EllipseGeometry(pt, 1.0, 1.0)
      hitList.Clear()
      VisualTreeHelper.HitTest(canvas1, Nothing, New HitTestResultCallback(AddressOf HitTestCallback), New GeometryHitTestParameters(hitArea))
      If hitList.Count > 0 Then
        For Each rect As Rectangle In hitList
          rect.Fill = Brushes.Blue
        Next
        Console.WriteLine("You hit " & hitList.Count.ToString() & " rectangles.")
      End If
    End Sub
    Public Function HitTestCallback(result As HitTestResult) As HitTestResultBehavior
      Dim intersectionDetail__1 As IntersectionDetail = DirectCast(result, GeometryHitTestResult).IntersectionDetail
      Select Case intersectionDetail__1
        Case IntersectionDetail.FullyContains
          hitList.Add(DirectCast(result.VisualHit, Rectangle))
          Return HitTestResultBehavior.[Continue]
        Case IntersectionDetail.Intersects
          Return HitTestResultBehavior.[Continue]
        Case IntersectionDetail.FullyInside
          Return HitTestResultBehavior.[Continue]
        Case Else
          Return HitTestResultBehavior.[Stop]
      End Select
    End Function
  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