TouchFrameEventArgs.GetTouchPoints(IInputElement) Yöntem

Tanım

Ad Alanı:

System.Windows.Input

Bütünleştirilmiş Kod:

PresentationCore.dll

Belirtilen öğeye göre her etkin dokunmatik cihaz için geçerli dokunma noktasını içeren bir koleksiyon döndürür.

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

Parametreler

relativeTo

IInputElement

Koordinat alanını tanımlayan öğe. WPF mutlak koordinatlarını kullanmak için olarak nullbelirtinrelativeTo.

Döndürülenler

TouchPointCollection

Her etkin TouchDeviceiçin geçerli TouchPoint öğesini içeren bir koleksiyon.

Örnekler

Aşağıdaki kod, içinden TouchFrameEventArgsalınan dokunma noktalarını işler. Tuvale bir dokunuş basıldığında, TouchDevice tuvale yakalanır. Dokunma kaldırıldığında, TouchDevice serbest bırakılır. Bir dokunuş tuval boyunca hareket ettiğinde, Id denetimi yapılır. , Id ilk dokunmayı gösteren birincil dokunma noktasının konumuyla eşleşiyorsa Id konumu kaydedilir. Hareket ikinci dokunuştan geldiyse, ilk dokunuşun konumundan ikinci dokunuşun konumuna bir çizgi çizilir.

Bu örnek, sınıfa genel bakış bölümünde Touch bulunan daha büyük bir örneğin parçasıdır.

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