TouchFrameEventArgs 类

定义

命名空间:

System.Windows.Input

程序集:

PresentationCore.dll

为 FrameReported 事件提供数据。

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 事件 FrameReported 并访问 中的 TouchFrameEventArgs触摸数据。 在 上Canvas按下触摸时，会将 TouchDevice 捕获到 。Canvas 当触摸解除时， TouchDevice 将释放 。 当触摸在 上 Canvas移动时， Id 将检查 。 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，则会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更大示例的一 Touch 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

事件FrameReported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 和 TouchMove、、 UIElementUIElement3D或 ContentElement。

TouchFrameEventArgs使用 获取与TouchPoint触摸事件相关的值。 从 中 TouchPoint，可以获取 Position 触摸的 ，并确定 TouchAction 是 Down、 Move还是 Up 操作。 还可以使用 TouchPoint 获取 TouchDevice。 从 中 TouchDevice，可以确定设备 Id 并获取有关所接触元素的信息。

属性

Timestamp

获取此事件的时间戳。

方法

Equals(Object)	确定指定对象是否等于当前对象。 (继承自 Object)
GetHashCode()	作为默认哈希函数。 (继承自 Object)
GetPrimaryTouchPoint(IInputElement)	返回主触摸设备相对于指定元素的当前触点。
GetTouchPoints(IInputElement)	返回一个集合，其中包含每个活动触摸设备相对于指定元素的当前触点。
GetType()	获取当前实例的 Type。 (继承自 Object)
MemberwiseClone()	创建当前 Object 的浅表副本。 (继承自 Object)
SuspendMousePromotionUntilTouchUp()	此成员未实现。
ToString()	返回表示当前对象的字符串。 (继承自 Object)