Hit Result Behavior : Mouse « Windows Presentation Foundation « C# / CSharp Tutorial

1. C# / CSharp 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.cs
using System;
using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Shapes;


namespace WpfApplication1
{
    public partial class HitTestExample : Window
    {
        private List<Rectangle> hitList = new List<Rectangle>();
        private EllipseGeometry hitArea = new EllipseGeometry();
        public HitTestExample()
        {
            InitializeComponent();
        }
        private void OnMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            foreach (Rectangle rect in canvas1.Children)
            {
                rect.Fill = Brushes.Red;
            }

            Point pt = e.GetPosition(canvas1);
            hitArea = new EllipseGeometry(pt, 1.0, 1.0);
            hitList.Clear();
            VisualTreeHelper.HitTest(canvas1, null,new HitTestResultCallback(HitTestCallback),new GeometryHitTestParameters(hitArea));
            if (hitList.Count > 0)
            {
                foreach (Rectangle rect in hitList)
                {
                    rect.Fill = Brushes.Blue;
                }
                Console.WriteLine("You hit " + hitList.Count.ToString() + " rectangles.");
            }
        }
        public HitTestResultBehavior HitTestCallback(HitTestResult result)
        {
            IntersectionDetail intersectionDetail = ((GeometryHitTestResult)result).IntersectionDetail;
            switch (intersectionDetail)
            {
                case IntersectionDetail.FullyContains:
                    hitList.Add((Rectangle)result.VisualHit);
                    return HitTestResultBehavior.Continue;
                case IntersectionDetail.Intersects:
                    return HitTestResultBehavior.Continue;
                case IntersectionDetail.FullyInside:
                    return HitTestResultBehavior.Continue;
                default:
                    return HitTestResultBehavior.Stop;
            }
        }
    }
}

24.123.Mouse
	24.123.1.	A line which monitors the mouse entering its area
	24.123.2.	Respond When the User Rotates the Mouse Wheel
	24.123.3.	Mouse Position and TranslateTransform
	24.123.4.	Mouse Position
	24.123.5.	Detect whether the mouse button is pressed or released using the MouseButtonState property.
	24.123.6.	Handler MouseLeftButtonDown and MouseLeftButtonUp events
	24.123.7.	Mouse Enter and leave a Border
	24.123.8.	Make an object follow the mouse pointer as it moves on the screen.
	24.123.9.	Use Mouse.AddPreviewMouseDownHandler(myEllipse, PreviewMouseDownEllipse);
	24.123.10.	Use Mouse.AddMouseDownHandler(myEllipse, MouseDownEllipse);
	24.123.11.	Use Mouse.PreviewMouseDown /Mouse.MouseDown Attribute from Grid element
	24.123.12.	Grid MouseMove
	24.123.13.	Grid MouseLeftButtonDown
	24.123.14.	Grid MouseLeftButtonUp
	24.123.15.	UI Element Mouse Clicked Events
	24.123.16.	Handles the MouseDown event on the Canvas
	24.123.17.	Handles the MouseDown event on the UniformGrid
	24.123.18.	Mouse cursor override and clear
	24.123.19.	Check the mouse event source
	24.123.20.	Use the Mouse Wheel action methods that are defined by the IScrollInfo interface
	24.123.21.	Mouse.LostMouseCaptureEvent
	24.123.22.	Use Mouse.Capture to let a Control capture an event
	24.123.23.	Capture Mouse Ellipse
	24.123.24.	Get mouse position with Mouse.GetPosition
	24.123.25.	Point Hit Test
	24.123.26.	Replease mouse with Mouse.Capture(null)
	24.123.27.	Hit Result Behavior
	24.123.28.	Get mouse clicked position as Point class
	24.123.29.	Get mouse clicked position with MouseButtonEventArgs.GetPosition