在 WinRT 应用程序中处理两指、三指、四指滑动手势

【问题标题】：Handling Two, Three, Four Fingers Swipe Gestures in WinRT App在 WinRT 应用程序中处理两指、三指、四指滑动手势
【发布时间】：2012-10-13 20:23:11
【问题描述】：

我有以下代码：

private Point initialpoint;

private void ManipulationStarted(object sender, ManipulationStartedRoutedEventArgs e)
{
    initialpoint = e.Position;
}

private void ManipulationDelta(object sender, ManipulationDeltaRoutedEventArgs e)
{
    Point currentpoint = e.Position;
    if (currentpoint.X - initialpoint.X >= 100)
    {
        System.Diagnostics.Debug.WriteLine("Swipe Right");
        e.Complete();
    }
}

我可以很容易地处理 1 个手指滑动手势，但我也想处理 2、3、4 个手指滑动手势。谁能告诉我该怎么做？

【问题讨论】：

    标签： c# .net xaml windows-8 windows-runtime


    【解决方案1】：

    根据此MSDN Forum Posting，您将需要使用pointer 通知。 工作示例代码的文档位于MSDN Library

    来自上一个链接：

    指针对象表示来自输入设备（例如鼠标、笔/触控笔、单指或多指）的单个、唯一的输入“接触”（PointerPoint）。系统在首次检测到接触时创建一个指针，并在指针离开（离开）检测范围或被取消时销毁它。在多个设备或多点触控输入的情况下，每个接触都被视为唯一的指针。

    请注意，我没有多点触控 Windows 8 设备来测试此代码。因此，它已经在 Simuator 中进行了所有限制的测试，并且如上述链接中所述，Windows 8 没有内置手势支持来检测多个手指，您必须使用较低级别的功能。

    首先，我在上面的 MSDN 示例代码中添加了两个字典，并为类定义的滑动阈值添加了两个变量。

    Dictionary<uint, Point> startLocation;
Dictionary<uint, bool> pointSwiped;
int swipeThresholdX = 100;
int swipeThresholdY = 100;

    然后我在表单的构造函数中初始化字典

    startLocation = new Dictionary<uint, Point>((int)SupportedContacts.Contacts);
pointSwiped = new Dictionary<uint, bool>((int)SupportedContacts.Contacts);

    然后，原始字典添加到或删除项目的每个地方我都对新字典进行了同样的操作

    添加：

    startLocation[pt.PointerId] = pt.Position;
pointSwiped[pt.PointerId] = false;

    删除：

    startLocation.Remove(pt.PointerId);
pointSwiped.Remove(pt.PointerId);

    然后最后把它们放在PointerMovedEvent中：

    private void targetContainer_PointerMoved(object sender, PointerRoutedEventArgs e)
{
    Windows.UI.Input.PointerPoint currentPoint = e.GetCurrentPoint(targetContainer);
    if (currentPoint.IsInContact)
    {
        if (startLocation.ContainsKey(currentPoint.PointerId))
        {
            Point startPoint = startLocation[currentPoint.PointerId];
            if (Math.Abs(currentPoint.Position.X - startPoint.X) > swipeThresholdX) // I only did one Axis for testing
            {
                pointSwiped[currentPoint.PointerId] = true;
            }
        }
    }
    updateInfoPop(e);
}

    最终修改的 MSDN 示例：

    using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;

// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=234238

namespace PointerInput
{
    /// <summary>
    /// An empty page that can be used on its own or navigated to within a Frame.
    /// </summary>
    public sealed partial class MainPage : Page
    {
        Windows.Devices.Input.TouchCapabilities SupportedContacts = new Windows.Devices.Input.TouchCapabilities();

        uint numActiveContacts;
        Dictionary<uint, Windows.UI.Input.PointerPoint> contacts;
        Dictionary<uint, Point> startLocation;
        Dictionary<uint, bool> pointSwiped;
        int swipeThresholdX = 100;
        int swipeThresholdY = 100;

        public MainPage()
        {
            this.InitializeComponent();
            numActiveContacts = 0;
            contacts = new Dictionary<uint, Windows.UI.Input.PointerPoint>((int)SupportedContacts.Contacts);
            startLocation = new Dictionary<uint, Point>((int)SupportedContacts.Contacts);
            pointSwiped = new Dictionary<uint, bool>((int)SupportedContacts.Contacts);
            targetContainer.PointerPressed += new PointerEventHandler(targetContainer_PointerPressed);
            targetContainer.PointerEntered += new PointerEventHandler(targetContainer_PointerEntered);
            targetContainer.PointerReleased += new PointerEventHandler(targetContainer_PointerReleased);
            targetContainer.PointerExited += new PointerEventHandler(targetContainer_PointerExited);
            targetContainer.PointerCanceled += new PointerEventHandler(targetContainer_PointerCanceled);
            targetContainer.PointerCaptureLost += new PointerEventHandler(targetContainer_PointerCaptureLost);
            targetContainer.PointerMoved += new PointerEventHandler(targetContainer_PointerMoved);
        }

        // PointerPressed and PointerReleased events do not always occur in pairs. 
        // Your app should listen for and handle any event that might conclude a pointer down action 
        // (such as PointerExited, PointerCanceled, and PointerCaptureLost).
        void targetContainer_PointerPressed(object sender, PointerRoutedEventArgs e)
        {
            if (Convert.ToBoolean(SupportedContacts.TouchPresent) && (numActiveContacts > SupportedContacts.Contacts))
            {
                // cannot support more contacts
                eventLog.Text += "\nNumber of contacts exceeds the number supported by the device.";
                return;
            }

            Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(targetContainer);

            // Update event sequence.
            eventLog.Text += "\nDown: " + pt.PointerId;

            // Change background color of target when pointer contact detected.
            targetContainer.Fill = new SolidColorBrush(Windows.UI.Colors.Green);

            // Check if pointer already exists (if enter occurred prior to down).
            if (contacts.ContainsKey(pt.PointerId))
            {
                return;
            }
            contacts[pt.PointerId] = pt;
            startLocation[pt.PointerId] = pt.Position;
            pointSwiped[pt.PointerId] = false;
            ++numActiveContacts;
            e.Handled = true;

            // Display pointer details.
            createInfoPop(e);
        }

        private void targetContainer_PointerEntered(object sender, PointerRoutedEventArgs e)
        {
            Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(targetContainer);

            // Update event sequence.
            eventLog.Text += "\nOver: " + pt.PointerId;

            if (contacts.Count == 0)
            {
                // Change background color of target when pointer contact detected.
                targetContainer.Fill = new SolidColorBrush(Windows.UI.Colors.Blue);
            }

            // Check if pointer already exists (if enter occurred prior to down).
            if (contacts.ContainsKey(pt.PointerId))
            {
                return;
            }

            // Push new pointer Id onto expando target pointers array.
            contacts[pt.PointerId] = pt;
            startLocation[pt.PointerId] = pt.Position;
            pointSwiped[pt.PointerId] = false;
            ++numActiveContacts;
            e.Handled = true;

            // Display pointer details.
            createInfoPop(e);
        }

        // Fires for for various reasons, including: 
        //    - User interactions
        //    - Programmatic caputre of another pointer
        //    - Captured pointer was deliberately released
        // PointerCaptureLost can fire instead of PointerReleased. 
        private void targetContainer_PointerCaptureLost(object sender, PointerRoutedEventArgs e)
        {
            Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(targetContainer);

            // Update event sequence.
            eventLog.Text += "\nPointer capture lost: " + pt.PointerId;

            if (contacts.ContainsKey(pt.PointerId))
            {
                checkSwipe();
                contacts[pt.PointerId] = null;
                contacts.Remove(pt.PointerId);
                startLocation.Remove(pt.PointerId);
                if (pointSwiped.ContainsKey(pt.PointerId))
                    pointSwiped.Remove(pt.PointerId);

                --numActiveContacts;
            }

            // Update the UI and pointer details.
            foreach (TextBlock tb in pointerInfo.Children)
            {
                if (tb.Name == e.Pointer.PointerId.ToString())
                {
                    pointerInfo.Children.Remove(tb);
                }
            }

            if (contacts.Count == 0)
            {
                targetContainer.Fill = new SolidColorBrush(Windows.UI.Colors.Black);
            }

            e.Handled = true;
        }

        // Fires for for various reasons, including: 
        //    - A touch contact is canceled by a pen coming into range of the surface.
        //    - The device doesn't report an active contact for more than 100ms.
        //    - The desktop is locked or the user logged off. 
        //    - The number of simultaneous contacts exceeded the number supported by the device.
        private void targetContainer_PointerCanceled(object sender, PointerRoutedEventArgs e)
        {
            Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(targetContainer);

            // Update event sequence.
            eventLog.Text += "\nPointer canceled: " + pt.PointerId;

            if (contacts.ContainsKey(pt.PointerId))
            {
                checkSwipe();
                contacts[pt.PointerId] = null;
                contacts.Remove(pt.PointerId);
                startLocation.Remove(pt.PointerId);
                if (pointSwiped.ContainsKey(pt.PointerId))
                    pointSwiped.Remove(pt.PointerId);

                --numActiveContacts;
            }

            // Update the UI and pointer details.
            foreach (TextBlock tb in pointerInfo.Children)
            {
                if (tb.Name == e.Pointer.PointerId.ToString())
                {
                    pointerInfo.Children.Remove(tb);
                }
            }

            if (contacts.Count == 0)
            {
                targetContainer.Fill = new SolidColorBrush(Windows.UI.Colors.Black);
            }

            e.Handled = true;
        }

        private void targetContainer_PointerExited(object sender, PointerRoutedEventArgs e)
        {
            Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(targetContainer);

            // Update event sequence.
            eventLog.Text += "\nPointer exited: " + pt.PointerId;

            if (contacts.ContainsKey(pt.PointerId))
            {
                checkSwipe();
                contacts[pt.PointerId] = null;
                contacts.Remove(pt.PointerId);
                startLocation.Remove(pt.PointerId);
                if (pointSwiped.ContainsKey(pt.PointerId))
                    pointSwiped.Remove(pt.PointerId);

                --numActiveContacts;
            }

            // Update the UI and pointer details.
            foreach (TextBlock tb in pointerInfo.Children)
            {
                if (tb.Name == e.Pointer.PointerId.ToString())
                {
                    pointerInfo.Children.Remove(tb);
                }
            }

            if (contacts.Count == 0)
            {
                targetContainer.Fill = new SolidColorBrush(Windows.UI.Colors.Gray);

            }
            e.Handled = true;
        }

        /// <summary>
        /// Invoked when this page is about to be displayed in a Frame.
        /// </summary>
        /// <param name="e">Event data that describes how this page was reached.  The Parameter
        /// property is typically used to configure the page.</param>
        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
        }

        void targetContainer_PointerReleased(object sender, PointerRoutedEventArgs e)
        {
            foreach (TextBlock tb in pointerInfo.Children)
            {
                if (tb.Name == e.Pointer.PointerId.ToString())
                {
                    pointerInfo.Children.Remove(tb);
                }
            }

            Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(targetContainer);

            // Update event sequence.
            eventLog.Text += "\nUp: " + pt.PointerId;

            // Change background color of target when pointer contact detected.
            targetContainer.Fill = new SolidColorBrush(Windows.UI.Colors.Red);

            if (contacts.ContainsKey(pt.PointerId))
            {
                checkSwipe();
                contacts[pt.PointerId] = null;
                contacts.Remove(pt.PointerId);
                startLocation.Remove(pt.PointerId);
                if(pointSwiped.ContainsKey(pt.PointerId))
                    pointSwiped.Remove(pt.PointerId);

                --numActiveContacts;
            }
            e.Handled = true;
        }

        private void targetContainer_PointerMoved(object sender, PointerRoutedEventArgs e)
        {
            Windows.UI.Input.PointerPoint currentPoint = e.GetCurrentPoint(targetContainer);
            if (currentPoint.IsInContact)
            {
                if (startLocation.ContainsKey(currentPoint.PointerId))
                {
                    Point startPoint = startLocation[currentPoint.PointerId];
                    if (Math.Abs(currentPoint.Position.X - startPoint.X) > swipeThresholdX) // I only did one Axis for testing
                    {
                        pointSwiped[currentPoint.PointerId] = true;
                    }
                }

            }
            updateInfoPop(e);
        }

        int numberOfSwipedFingers()
        {
            int count = 0;
            foreach (var item in pointSwiped)
            {
                if (item.Value) { count += 1; }
            }
            return count;
        }

        void checkSwipe()
        {
            int fingers = numberOfSwipedFingers();
            if (fingers > 1)
            {
                eventLog.Text += "\nNumber of Swiped fingers = " + fingers;
            }
            else if (fingers == 1)
            {
                eventLog.Text += "\nNumber of Swiped fingers = " + fingers;
            }
            if(fingers > 0)
                pointSwiped.Clear();
        }            

        void createInfoPop(PointerRoutedEventArgs e)
        {
            Windows.UI.Input.PointerPoint currentPoint = e.GetCurrentPoint(targetContainer);
            TextBlock pointerDetails = new TextBlock();
            pointerDetails.Name = currentPoint.PointerId.ToString();
            pointerDetails.Foreground = new SolidColorBrush(Windows.UI.Colors.White);
            pointerInfo.Children.Add(pointerDetails);
            pointerDetails.Text = queryPointer(e);
        }

        void updateInfoPop(PointerRoutedEventArgs e)
        {
            foreach (TextBlock pointerDetails in pointerInfo.Children)
            {
                if (pointerDetails.Name == e.Pointer.PointerId.ToString())
                {
                    pointerDetails.Text = queryPointer(e);
                }
            }
        }

        String queryPointer(PointerRoutedEventArgs e)
        {
            Windows.UI.Input.PointerPoint currentPoint = e.GetCurrentPoint(targetContainer);
            String details = "";
            switch (e.Pointer.PointerDeviceType)
            {
                case Windows.Devices.Input.PointerDeviceType.Mouse:
                    details += "\nPointer type: mouse";
                    break;
                case Windows.Devices.Input.PointerDeviceType.Pen:
                    details += "\nPointer type: pen";
                    if (e.Pointer.IsInContact)
                    {
                        details += "\nPressure: " + currentPoint.Properties.Pressure;
                        details += "\nrotation: " + currentPoint.Properties.Orientation;
                        details += "\nTilt X: " + currentPoint.Properties.XTilt;
                        details += "\nTilt Y: " + currentPoint.Properties.YTilt;
                        details += "\nBarrel button pressed: " + currentPoint.Properties.IsBarrelButtonPressed;
                    }
                    break;
                case Windows.Devices.Input.PointerDeviceType.Touch:
                    details += "\nPointer type: touch";
                    details += "\nrotation: " + currentPoint.Properties.Orientation;
                    details += "\nTilt X: " + currentPoint.Properties.XTilt;
                    details += "\nTilt Y: " + currentPoint.Properties.YTilt;
                    break;
                default:
                    details += "\nPointer type: n/a";
                    break;
            }

            GeneralTransform gt = targetContainer.TransformToVisual(page);
            Point screenPoint;

            screenPoint = gt.TransformPoint(new Point(currentPoint.Position.X, currentPoint.Position.Y));
            details += "\nPointer Id: " + currentPoint.PointerId.ToString() +
                "\nPointer location (parent): " + currentPoint.Position.X + ", " + currentPoint.Position.Y +
                "\nPointer location (screen): " + screenPoint.X + ", " + screenPoint.Y;
            return details;
        }
    }
}

    【讨论】：

    • @Programmer 我看到的问题是您在稍微不同的时间释放多个点，您可能应该回到我在示例中使用的 CheckSwipe 例程，或者在它周围加个锁或做其他事情以防止其他手指释放进入，直到第一个手指完成。不幸的是，使用模拟器我无法模拟更多被释放的两个手指，而且它们是同时释放的。不过我会进一步研究一下
    • @Programmer 我去看看，可能要一天左右。
    • 你能看看这个问题吗？ stackoverflow.com/questions/13011920/…
    • 您好，最大触摸输入点数是多少？此设备是否依赖于@MarkHall？
    • @poitroae。是的，它将取决于设备。
    【解决方案2】：

    我将 Mark Hall 的答案改编为单独的课程，并处理向上、向下、向左和向右滑动。它仍然存在问题，您可以在不同时间举起手指并获得多个事件，并且可以改进，尽管它可以满足我的需求：

    public enum DirectionSwiped
{
    None,
    Up,
    Down,
    Left,
    Right
}


public class SwipeEventArgs : EventArgs
{
    public DirectionSwiped Direction { get; set; }
    public int NumberOfTouches { get; set; }
}


public class SwipeGestureDetector
{
    public EventHandler<SwipeEventArgs> SwipeDetected;




    // How much of the grid needs to be covered by the swipe?
    private const double SWIPE_THRESHOLD = 0.5;

    // How much drift is allowed in the opposite axis?
    private const int ALLOWED_DRIFT = 100;

    Windows.Devices.Input.TouchCapabilities SupportedContacts = new Windows.Devices.Input.TouchCapabilities();

    uint numActiveContacts;
    Dictionary<uint, Windows.UI.Input.PointerPoint> contacts;
    Dictionary<uint, Point> startLocation;
    Dictionary<uint, DirectionSwiped> pointSwiped;

    private Grid mGrid;





    public SwipeGestureDetector(Grid grid)
    {
        mGrid = grid;

        numActiveContacts = 0;
        contacts = new Dictionary<uint, Windows.UI.Input.PointerPoint>((int)SupportedContacts.Contacts);
        startLocation = new Dictionary<uint, Point>((int)SupportedContacts.Contacts);
        pointSwiped = new Dictionary<uint, DirectionSwiped>((int)SupportedContacts.Contacts);
        grid.PointerPressed += new PointerEventHandler(Grid_PointerPressed);
        grid.PointerEntered += new PointerEventHandler(Grid_PointerEntered);
        grid.PointerReleased += new PointerEventHandler(Grid_PointerReleased);
        grid.PointerExited += new PointerEventHandler(Grid_PointerExited);
        grid.PointerCanceled += new PointerEventHandler(Grid_PointerCanceled);
        grid.PointerCaptureLost += new PointerEventHandler(Grid_PointerCaptureLost);
        grid.PointerMoved += new PointerEventHandler(Grid_PointerMoved);
    }





    // PointerPressed and PointerReleased events do not always occur in pairs. 
    // Your app should listen for and handle any event that might conclude a pointer down action 
    // (such as PointerExited, PointerCanceled, and PointerCaptureLost).
    void Grid_PointerPressed(object sender, PointerRoutedEventArgs e)
    {
        if (Convert.ToBoolean(SupportedContacts.TouchPresent) && (numActiveContacts > SupportedContacts.Contacts))
        {
            // cannot support more contacts
            Debug.WriteLine("\nNumber of contacts exceeds the number supported by the device.");
            return;
        }

        Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(mGrid);

        // Check if pointer already exists (if enter occurred prior to down).
        if (contacts.ContainsKey(pt.PointerId))
        {
            return;
        }
        contacts[pt.PointerId] = pt;
        startLocation[pt.PointerId] = pt.Position;
        pointSwiped[pt.PointerId] = DirectionSwiped.None;
        ++numActiveContacts;
        e.Handled = true;
    }


    private void Grid_PointerEntered(object sender, PointerRoutedEventArgs e)
    {
        Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(mGrid);

        // Check if pointer already exists (if enter occurred prior to down).
        if (contacts.ContainsKey(pt.PointerId))
        {
            return;
        }

        // Push new pointer Id onto expando target pointers array.
        contacts[pt.PointerId] = pt;
        startLocation[pt.PointerId] = pt.Position;
        pointSwiped[pt.PointerId] = DirectionSwiped.None;
        ++numActiveContacts;
        e.Handled = true;

    }


    // Fires for for various reasons, including: 
    //    - User interactions
    //    - Programmatic caputre of another pointer
    //    - Captured pointer was deliberately released
    // PointerCaptureLost can fire instead of PointerReleased. 
    private void Grid_PointerCaptureLost(object sender, PointerRoutedEventArgs e)
    {
        Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(mGrid);

        if (contacts.ContainsKey(pt.PointerId))
        {
            checkSwipe();
            contacts[pt.PointerId] = null;
            contacts.Remove(pt.PointerId);
            startLocation.Remove(pt.PointerId);
            if (pointSwiped.ContainsKey(pt.PointerId))
                pointSwiped.Remove(pt.PointerId);

            --numActiveContacts;
        }

        e.Handled = true;
    }


    // Fires for for various reasons, including: 
    //    - A touch contact is canceled by a pen coming into range of the surface.
    //    - The device doesn't report an active contact for more than 100ms.
    //    - The desktop is locked or the user logged off. 
    //    - The number of simultaneous contacts exceeded the number supported by the device.
    private void Grid_PointerCanceled(object sender, PointerRoutedEventArgs e)
    {
        Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(mGrid);

        if (contacts.ContainsKey(pt.PointerId))
        {
            checkSwipe();
            contacts[pt.PointerId] = null;
            contacts.Remove(pt.PointerId);
            startLocation.Remove(pt.PointerId);
            if (pointSwiped.ContainsKey(pt.PointerId))
                pointSwiped.Remove(pt.PointerId);

            --numActiveContacts;
        }

        e.Handled = true;
    }


    private void Grid_PointerExited(object sender, PointerRoutedEventArgs e)
    {
        Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(mGrid);

        if (contacts.ContainsKey(pt.PointerId))
        {
            checkSwipe();
            contacts[pt.PointerId] = null;
            contacts.Remove(pt.PointerId);
            startLocation.Remove(pt.PointerId);
            if (pointSwiped.ContainsKey(pt.PointerId))
                pointSwiped.Remove(pt.PointerId);

            --numActiveContacts;
        }
        e.Handled = true;
    }



    void Grid_PointerReleased(object sender, PointerRoutedEventArgs e)
    {
        Windows.UI.Input.PointerPoint pt = e.GetCurrentPoint(mGrid);

        if (contacts.ContainsKey(pt.PointerId))
        {
            checkSwipe();
            contacts[pt.PointerId] = null;
            contacts.Remove(pt.PointerId);
            startLocation.Remove(pt.PointerId);
            if (pointSwiped.ContainsKey(pt.PointerId))
                pointSwiped.Remove(pt.PointerId);

            --numActiveContacts;
        }
        e.Handled = true;
    }


    private void Grid_PointerMoved(object sender, PointerRoutedEventArgs e)
    {
        Windows.UI.Input.PointerPoint currentPoint = e.GetCurrentPoint(mGrid);
        if (currentPoint.IsInContact)
        {
            if (startLocation.ContainsKey(currentPoint.PointerId))
            {
                Point startPoint = startLocation[currentPoint.PointerId];

                // Compare startPoint to current location and determine if that point did a swipe?

                double horizontalMovement = currentPoint.Position.X - startPoint.X;
                double verticalMovement = currentPoint.Position.Y - startPoint.Y;

                double horizontalDistance = Math.Abs(horizontalMovement);
                double verticalDistance = Math.Abs(verticalMovement);

                double requiredLeftMovement = mGrid.ActualWidth * SWIPE_THRESHOLD * -1;
                double requiredRightMovement = mGrid.ActualWidth * SWIPE_THRESHOLD;

                double requiredUpMovement = mGrid.ActualHeight * SWIPE_THRESHOLD * -1;
                double requiredDownMovement = mGrid.ActualHeight * SWIPE_THRESHOLD;

                if (verticalMovement < requiredUpMovement && horizontalDistance < 100)
                {
                    pointSwiped[currentPoint.PointerId] = DirectionSwiped.Up;
                }
                else if (verticalMovement > requiredDownMovement && horizontalDistance < ALLOWED_DRIFT)
                {
                    pointSwiped[currentPoint.PointerId] = DirectionSwiped.Down;
                }
                else if (horizontalMovement > requiredRightMovement && verticalDistance < ALLOWED_DRIFT)
                {
                    pointSwiped[currentPoint.PointerId] = DirectionSwiped.Right;
                }
                else if (horizontalMovement < requiredLeftMovement && verticalDistance < ALLOWED_DRIFT)
                {
                    pointSwiped[currentPoint.PointerId] = DirectionSwiped.Left;
                }
            }
        }
    }





    void checkSwipe()
    {
        NotififyListenerIfSwiped(DirectionSwiped.Up);
        NotififyListenerIfSwiped(DirectionSwiped.Down);
        NotififyListenerIfSwiped(DirectionSwiped.Left);
        NotififyListenerIfSwiped(DirectionSwiped.Right);
    }


    private void NotififyListenerIfSwiped(DirectionSwiped direction)
    {
        int fingers = numberOfSwipedFingers(direction);
        if (fingers >= 1)
        {
            if (SwipeDetected != null)
            {
                SwipeDetected(this, new SwipeEventArgs() { Direction = direction, NumberOfTouches = fingers });
            }
        }

        if (fingers > 0)
            pointSwiped.Clear();
    }


    int numberOfSwipedFingers(DirectionSwiped direction)
    {
        int count = 0;
        foreach (var item in pointSwiped)
        {
            DirectionSwiped swipe = item.Value;
            if (swipe == direction)
            {
                count += 1;
            }
        }
        return count;
    }


}

    用法

        public void Gesture_Detected(Object sender, SwipeEventArgs e)
    {
        Debug.WriteLine("Number of touches: " + e.NumberOfTouches + " Direction: " + e.Direction);
    }


    public MainPage()
    {
        this.InitializeComponent();

        SwipeGestureDetector gestureDetector = new SwipeGestureDetector(this.rootGrid);
        gestureDetector.SwipeDetected += Gesture_Detected;

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