在WinRT应用程序中处理向上滑动,向下滑动,向左滑动和向右滑动手势

Question

我有以下代码:

public MainPage()
{
    this.InitializeComponent();
    this.ManipulationStarting += MainPage_ManipulationStarting;
    this.ManipulationStarted += MainPage_ManipulationStarted;
    this.ManipulationInertiaStarting += MainPage_ManipulationInertiaStarting;
    this.ManipulationDelta += MainPage_ManipulationDelta;
    this.ManipulationCompleted += MainPage_ManipulationCompleted;
}
void MainPage_ManipulationStarting(object sender, ManipulationStartingRoutedEventArgs e)
{
    Debug.WriteLine("MainPage_ManipulationStarting");
}
void MainPage_ManipulationStarted(object sender, ManipulationStartedRoutedEventArgs e)
{
    Debug.WriteLine("MainPage_ManipulationStarted");
}
void MainPage_ManipulationInertiaStarting(object sender, ManipulationInertiaStartingRoutedEventArgs e)
{
    Debug.WriteLine("MainPage_ManipulationInertiaStarting");
}
void MainPage_ManipulationDelta(object sender, ManipulationDeltaRoutedEventArgs e)
{
    Debug.WriteLine("MainPage_ManipulationDelta");
}
void MainPage_ManipulationCompleted(object sender, ManipulationCompletedRoutedEventArgs e)
{
    Debug.WriteLine("MainPage_ManipulationCompleted");
}

但我不知道如何使用Manipulation事件.你能描述一下如何处理向上,向下,向左和向右滑动的手势吗？

Answer 1

操纵事件为您提供翻译值.操纵Delta将持续射击,直到您的操纵与惯性一起完成.在这种情况下,检查移动是否是惯性的(正常移动不应被视为滑动)并检测初始位置和当前位置之间的差异.

达到阈值后,触发向上/向下/向左/向右滑动事件.并立即停止操纵,以避免一次又一次地触发同一事件.

以下代码将帮助您,

    private Point initialpoint;

    private void Grid_ManipulationStarted_1(object sender, ManipulationStartedRoutedEventArgs e)
    {
        initialpoint = e.Position;
    }

    private void Grid_ManipulationDelta_1(object sender, ManipulationDeltaRoutedEventArgs e)
    {
        if (e.IsInertial)
        {
            Point currentpoint = e.Position;
            if (currentpoint.X - initialpoint.X >= 500)//500 is the threshold value, where you want to trigger the swipe right event
            {
                System.Diagnostics.Debug.WriteLine("Swipe Right");
                e.Complete();
            }
        }
    }