WPF 命中测试HitTest

获取不规则图片的点击事件，

如果一个Canvas中，有很多图形，比如下图：矩形，菱形等。

如果每个图形都加一个点击事件，想要一个通用的方法，获取鼠标点击在了哪个图形上，这里可以使用VisualTreeHelper.HitTest方法。

直接看看示例代码：

MainWindow.xaml:

<Window x:Class="wpfcore.MainWindow"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:d="http://schemas.microsoft.com/expression/blend/2008"xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"xmlns:local="clr-namespace:wpfcore" xmlns:controls="http://metro.mahapps.com/winfx/xaml/controls"mc:Ignorable="d"Background="LightBlue"UseLayoutRounding="True"Title="MainWindow" Width="600" Height="340"><WrapPanel HorizontalAlignment="Center" VerticalAlignment="Center" Name="panel" MouseUp="mouseUp"><Path x:Name="矩形1" Margin="5" Fill="Red" Data="M0 0,100 0,100,100,0 100Z"/><Path x:Name="矩形2" Margin="-5" Fill="Green" Data="M0 0,100 0,100,100,0 100Z"><Path.RenderTransform><RotateTransform CenterX="50" CenterY="50" Angle="60"/></Path.RenderTransform></Path><Path x:Name="菱形1" Stroke="Red" Fill="Red"><Path.Data><PathGeometry><PathFigure IsClosed="True" StartPoint="50,0"><LineSegment Point="75,50"></LineSegment><LineSegment Point="50,100"></LineSegment><LineSegment Point="25,50"></LineSegment></PathFigure></PathGeometry></Path.Data></Path><Path x:Name="菱形2" Stroke="Red" Fill="Red"><Path.Data><PathGeometry><PathFigure IsClosed="True" StartPoint="50,0"><LineSegment Point="75,50"></LineSegment><LineSegment Point="50,100"></LineSegment><LineSegment Point="25,50"></LineSegment></PathFigure><PathGeometry.Transform><RotateTransform Angle="-115" CenterX="50" CenterY="100"></RotateTransform></PathGeometry.Transform></PathGeometry></Path.Data></Path></WrapPanel>
</Window>

MainWindow.cs:

using System;
using System.Collections.ObjectModel;
using System.Windows;
using System.Windows.Input;
using System.Windows.Media;namespace wpfcore
{public partial class MainWindow : Window{public MainWindow(){InitializeComponent();DataContext = this;}private void mouseUp(object sender, MouseButtonEventArgs e){var p = e.GetPosition(sender as UIElement);VisualTreeHelper.HitTest(panel, null, callback, new PointHitTestParameters(p));System.Diagnostics.Debug.WriteLine($"------------------------");}private HitTestResultBehavior callback(HitTestResult result){System.Diagnostics.Debug.WriteLine($"点击了{result.VisualHit.GetValue(NameProperty)}");return HitTestResultBehavior.Continue;}}
}