WPF多点触控跟踪触摸点

2019年8月3日 370次阅读

我正在尝试做一个简单的应用程序,当用户触摸屏幕时,应用程序创建简单的点,椭圆或sth 2d对象,当用户移动他的手指时,它应该跟随,但是当有一个第二触摸时同时也必须创建新对象并对用户移动做同样的事情.每当用户指责时,对象将被删除.

要做到这一点,我试图改变这个链接http://www.cookingwithxaml.com/recipes/wpf4/wpf4touch.zip的触摸代码,但我无法弄清楚我应该改变哪种方法？

你能提出一些建议吗？

谢谢.

最佳答案 下面是一些示例xaml / C#代码,可以执行我认为您想要的内容：

MainWindow.xaml：

<Window x:Class="MultitouchExperiments.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <Canvas
            x:Name="TouchCanvas"
            TouchDown="TouchCanvas_TouchDown" TouchUp="TouchCanvas_TouchUp"
            TouchMove="TouchCanvas_TouchMove" TouchLeave="TouchCanvas_TouchLeave"
            TouchEnter="TouchCanvas_TouchEnter"
            VerticalAlignment="Stretch" HorizontalAlignment="Stretch"
            Background="Black"
            IsManipulationEnabled="True" />
    </Grid>
</Window>

MainWindow.xaml.cs：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Diagnostics;

namespace MultitouchExperiments
{
  /// <summary>
  /// Interaction logic for MainWindow.xaml
  /// </summary>
  public partial class MainWindow : Window
  {
    Dictionary<TouchDevice, Ellipse> _Followers = new Dictionary<TouchDevice, Ellipse>();

    public MainWindow()
    {
      InitializeComponent();
    }

    private void TouchCanvas_TouchDown(object sender, TouchEventArgs e)
    {
      TouchCanvas.CaptureTouch(e.TouchDevice);

      Ellipse follower = new Ellipse();
      follower.Width = follower.Height = 50;
      follower.Fill = Brushes.White;
      follower.Stroke = Brushes.White;

      TouchPoint point = e.GetTouchPoint(TouchCanvas);

      follower.RenderTransform = new TranslateTransform(point.Position.X, point.Position.Y);

      _Followers[e.TouchDevice] = follower;

      TouchCanvas.Children.Add(follower);
    }

    private void TouchCanvas_TouchUp(object sender, TouchEventArgs e)
    {
      TouchCanvas.ReleaseTouchCapture(e.TouchDevice);

      TouchCanvas.Children.Remove(_Followers[e.TouchDevice]);
      _Followers.Remove(e.TouchDevice);
    }

    private void TouchCanvas_TouchMove(object sender, TouchEventArgs e)
    {
      if (e.TouchDevice.Captured == TouchCanvas)
      {
        Ellipse follower = _Followers[e.TouchDevice];
        TranslateTransform transform = follower.RenderTransform as TranslateTransform;

        TouchPoint point = e.GetTouchPoint(TouchCanvas);

        transform.X = point.Position.X;
        transform.Y = point.Position.Y;
      }
    }

    private void TouchCanvas_TouchLeave(object sender, TouchEventArgs e)
    {
      //Debug.WriteLine("leave " + e.TouchDevice.Id);
    }

    private void TouchCanvas_TouchEnter(object sender, TouchEventArgs e)
    {
      //Debug.WriteLine("enter " + e.TouchDevice.Id);
    }
  }
}
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