private readonly Stopwatch _doubleTapStopwatch = new Stopwatch();
private Point _lastTapLocation;

public event EventHandler DoubleTouchDown;

protected virtual void OnDoubleTouchDown()
{
    if (DoubleTouchDown != null)
        DoubleTouchDown(this, EventArgs.Empty);
}

private bool IsDoubleTap(TouchEventArgs e)
{
    Point currentTapPosition = e.GetTouchPoint(this).Position;
    bool tapsAreCloseInDistance = currentTapPosition.GetDistanceTo(_lastTapLocation) < 40;
    _lastTapLocation = currentTapPosition;

    TimeSpan elapsed = _doubleTapStopwatch.Elapsed;
    _doubleTapStopwatch.Restart();
    bool tapsAreCloseInTime = (elapsed != TimeSpan.Zero && elapsed < TimeSpan.FromSeconds(0.7));

    return tapsAreCloseInDistance && tapsAreCloseInTime;
}

private void OnPreviewTouchDown(object sender, TouchEventArgs e)
{
    if (IsDoubleTap(e))
        OnDoubleTouchDown();
}

它在PreviewTouchDown中检查它是否是DoubleTap。

票数 11

Stack Overflow用户

发布于 2015-04-13 09:11:14

Jowens answer对我帮助很大(如果我的声誉允许，我会给它加码；)但我必须调整它，所以它只需双击就能工作。原始代码确实认为任何超过2的轻敲都是双击。将_lastTapLocation更改为可空并在双击时将其重置会有所帮助。

private Point? _lastTapLocation;

private bool IsDoubleTap(TouchEventArgs e)
    {
        Point currentTapPosition = e.GetTouchPoint(this).Position;
        bool tapsAreCloseInDistance = false;
        if (_lastTapLocation != null)
        {
            tapsAreCloseInDistance = GetDistanceBetweenPoints(currentTapPosition, (Point)_lastTapLocation) < 70;
        }
        _lastTapLocation = currentTapPosition;

        TimeSpan elapsed = _doubleTapStopwatch.Elapsed;
        _doubleTapStopwatch.Restart();
        bool tapsAreCloseInTime = (elapsed != TimeSpan.Zero && elapsed < TimeSpan.FromSeconds(0.7));

        if (tapsAreCloseInTime && tapsAreCloseInDistance)
        {
            _lastTapLocation = null;
        }
        return tapsAreCloseInDistance && tapsAreCloseInTime;
    }

票数 3

Stack Overflow用户

发布于 2016-06-09 11:54:02

我认为利用StylusSystemGesture事件更合适。这是我的代码。

    public static class ext
{
private static Point? _lastTapLocation;
        private static readonly Stopwatch _DoubleTapStopwatch = new Stopwatch();
        public static bool IsDoubleTap(this StylusSystemGestureEventArgs e, IInputElement iInputElement)
        {
            Point currentTapPosition = e.GetPosition(iInputElement);
            bool tapsAreCloseInDistance = false;
            if (_lastTapLocation != null)
            {
                tapsAreCloseInDistance = GetDistanceBetweenPoints(currentTapPosition, (Point)_lastTapLocation) < 70;
            }
            _lastTapLocation = currentTapPosition;

            TimeSpan elapsed = _DoubleTapStopwatch.Elapsed;
            _DoubleTapStopwatch.Restart();
            bool tapsAreCloseInTime = (elapsed != TimeSpan.Zero && elapsed < TimeSpan.FromSeconds(0.7));

            if (tapsAreCloseInTime && tapsAreCloseInDistance)
            {
                _lastTapLocation = null;
            }
            return tapsAreCloseInDistance && tapsAreCloseInTime;
        }
}

用法：

 private void UIElement_OnStylusSystemGesture(object sender, StylusSystemGestureEventArgs e)
    {
        if (e.SystemGesture == SystemGesture.Tap)
        {
            if (e.IsDoubleTap(sender as IInputElement))
            {
               // Do your stuff here
            }
        }
    }