TouchFrameEventArgs 类

定义

public ref class TouchFrameEventArgs sealed : EventArgs

public sealed class TouchFrameEventArgs : EventArgs

type TouchFrameEventArgs = class
    inherit EventArgs

Public NotInheritable Class TouchFrameEventArgs
Inherits EventArgs

继承

Object

EventArgs

TouchFrameEventArgs

示例

以下示例处理 FrameReported 事件并访问该事件中的 TouchFrameEventArgs触摸数据。 当触摸按下Canvas时，会TouchDevice捕获到该触摸。Canvas 当触摸解除时，将 TouchDevice 释放触摸。 当触摸移动过 Canvas时， Id 将选中它。 如果移动来自第一次触摸，则会记录其位置。 如果移动来自第二次触摸，则从第一次触摸的位置到第二次触摸的位置绘制一条线。

此示例是类概述中提供的大型示例的 Touch 一部分。

public partial class MainWindow : Window
{
    // Variables for tracking the position of two points.
    Point pt1, pt2 = new Point();
    
    public MainWindow()
    {
        InitializeComponent();
        Touch.FrameReported += new TouchFrameEventHandler(Touch_FrameReported);
    }

    void Touch_FrameReported(object sender, TouchFrameEventArgs e)
    {
        if (this.canvas1 != null)
        {
            foreach (TouchPoint _touchPoint in e.GetTouchPoints(this.canvas1))
            {
                if (_touchPoint.Action == TouchAction.Down)
                {
                    // Clear the canvas and capture the touch to it.
                    this.canvas1.Children.Clear();
                    _touchPoint.TouchDevice.Capture(this.canvas1);
                }

                else if (_touchPoint.Action == TouchAction.Move && e.GetPrimaryTouchPoint(this.canvas1) != null)
                {   
                    // This is the first (primary) touch point. Just record its position.
                    if (_touchPoint.TouchDevice.Id == e.GetPrimaryTouchPoint(this.canvas1).TouchDevice.Id)
                    {
                        pt1.X = _touchPoint.Position.X;
                        pt1.Y = _touchPoint.Position.Y;
                    }

                    // This is not the first touch point. Draw a line from the first point to this one.
                    else if (_touchPoint.TouchDevice.Id != e.GetPrimaryTouchPoint(this.canvas1).TouchDevice.Id)
                    {
                        pt2.X = _touchPoint.Position.X;
                        pt2.Y = _touchPoint.Position.Y;

                        Line _line = new Line();
                        _line.Stroke = new RadialGradientBrush(Colors.White, Colors.Black);
                        _line.X1 = pt1.X;
                        _line.X2 = pt2.X;
                        _line.Y1 = pt1.Y;
                        _line.Y2 = pt2.Y;
                        _line.StrokeThickness = 2;
                        this.canvas1.Children.Add(_line);
                    }
                }

                else if (_touchPoint.Action == TouchAction.Up)
                {
                    // If this touch is captured to the canvas, release it.
                    if (_touchPoint.TouchDevice.Captured == this.canvas1)
                    {
                        this.canvas1.ReleaseTouchCapture(_touchPoint.TouchDevice);
                    }
                }
            }                        
        }
    }
}

Class MainWindow
    ' Variables for tracking the position of two points.
    Private pt1, pt2 As Point

    Public Sub New()
        InitializeComponent()
        AddHandler Touch.FrameReported, AddressOf Touch_FrameReported
    End Sub

    Private Sub Touch_FrameReported(ByVal sender As System.Object, ByVal e As System.Windows.Input.TouchFrameEventArgs)
        If (canvas1 IsNot Nothing) Then
            For Each _touchPoint In e.GetTouchPoints(Me.canvas1)

                If _touchPoint.Action = TouchAction.Down Then
                    ' Clear the canvas and capture the touch to it.
                    canvas1.Children.Clear()
                    _touchPoint.TouchDevice.Capture(canvas1)

                ElseIf _touchPoint.Action = TouchAction.Move Then
                    ' This is the first (primary) touch point. Just record its position.
                    If _touchPoint.TouchDevice.Id = e.GetPrimaryTouchPoint(Me.canvas1).TouchDevice.Id Then
                        pt1.X = _touchPoint.Position.X
                        pt1.Y = _touchPoint.Position.Y

                        ' This is not the first touch point; draw a line from the first point to this one.
                    ElseIf _touchPoint.TouchDevice.Id <> e.GetPrimaryTouchPoint(Me.canvas1).TouchDevice.Id Then
                        pt2.X = _touchPoint.Position.X
                        pt2.Y = _touchPoint.Position.Y

                        Dim _line As New Line()
                        _line.Stroke = New RadialGradientBrush(Colors.White, Colors.Black)
                        _line.X1 = pt1.X
                        _line.X2 = pt2.X
                        _line.Y1 = pt1.Y
                        _line.Y2 = pt2.Y

                        _line.StrokeThickness = 2
                        Me.canvas1.Children.Add(_line)
                    End If

                ElseIf _touchPoint.Action = TouchAction.Up Then
                    ' If this touch is captured to the canvas, release it.
                    If (_touchPoint.TouchDevice.Captured Is canvas1) Then
                        canvas1.ReleaseTouchCapture(_touchPoint.TouchDevice)
                    End If
                End If
            Next
        End If
    End Sub
End Class

注解

FrameReported 事件包含在 Windows Presentation Foundation （WPF） 中，以支持与 Silverlight 的兼容性。 如果不必确保与 Silverlight 的兼容性，请使用触摸事件，例如TouchDown，on 和、on TouchMoveUIElement或UIElement3D。ContentElement

使用此方法 TouchFrameEventArgs 获取 TouchPoint 与触摸事件相关的值。 从中 TouchPoint，你可以获取 Position 触摸并确定 TouchAction 是一个 Down， Move还是 Up 操作。 还可以使用该 TouchPoint 来获取 TouchDevice。 从中 TouchDevice，你可以确定设备 Id 并获取有关所触摸元素的信息。