TouchFrameEventArgs.GetTouchPoints(IInputElement) Método

Definición

Espacio de nombres:

System.Windows.Input

Ensamblado:

PresentationCore.dll

Devuelve una colección que contiene el punto táctil actual para cada dispositivo táctil activo relativo al elemento especificado.

public:
 System::Windows::Input::TouchPointCollection ^ GetTouchPoints(System::Windows::IInputElement ^ relativeTo);

public System.Windows.Input.TouchPointCollection GetTouchPoints (System.Windows.IInputElement relativeTo);

member this.GetTouchPoints : System.Windows.IInputElement -> System.Windows.Input.TouchPointCollection

Public Function GetTouchPoints (relativeTo As IInputElement) As TouchPointCollection

Parámetros

relativeTo

IInputElement

Elemento que define el espacio de coordenadas. Para emplear coordenadas absolutas de WPF, especifique relativeTo como null.

Devoluciones

TouchPointCollection

Colección que contiene el TouchPoint actual para cada TouchDevice activo.

Ejemplos

El código siguiente procesa los puntos táctiles recuperados de TouchFrameEventArgs. Cuando se presiona un toque en el lienzo, TouchDevice se captura en el lienzo. Cuando se eleva la función táctil, TouchDevice se libera . Cuando un toque se mueve por el lienzo, se comprueba .Id Id Si coincide con el Id del punto táctil principal, que indica la primera entrada táctil, se registra su ubicación. Si el movimiento procede del segundo toque, se dibuja una línea desde la posición del primer toque hasta la posición del segundo toque.

Este ejemplo forma parte de un ejemplo más grande que está disponible en la información general de la Touch clase.

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);
        }
    }
}

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