C# PanGesture在UWP Xamarin表单中只调用了一次PanGesture更新事件。这就是为什么拖动不起作用

我已经使用代码在图像上添加了平移手势，然后在平移手势更新方法中调用了它的所有情况

它立即进入运行状态，并设置本机视图（图像）相对于父视图（窗口）的坐标。然后它停止并不执行任何对pan手势更新方法的调用

/*Creation of image*/
void CreateImage() {
    var panGestureRecognizer = new PanGestureRecognizer();
    panGestureRecognizer.PanUpdated += PanGestureRecognizer_PanUpdated;
    Image image = new Image()
    {
        HeightRequest = 40,
        WidthRequest = 40,
        Margin = new Thickness( 10, 10, 10, 0 ),
        Aspect = Aspect.AspectFit,
        VerticalOptions = LayoutOptions.Start,
        Source = ImageSource.FromUri( new Uri( $"{codebookJSONModel.Violation.IconPath}" ) ),
    };
    image.GestureRecognizers.Add( panGestureRecognizer );
}

/*PanGesture Updated Event*/

private async void PanGestureRecognizer_PanUpdated( object sender, PanUpdatedEventArgs e ) {
    Console.WriteLine( "PanGestureRecognizer_PanUpdated" );
    var layout = (Image)sender;
    switch ( e.StatusType ) {
    case GestureStatus.Started:
        Console.WriteLine( "PanGestureRecognizer_Started" );
        inspectionViewModel.totalX = 0;
        inspectionViewModel.totalY = 0;
        break;

    case GestureStatus.Running:
        // Translate and ensure we don't pan beyond the wrapped user interface element bounds.
        Debug.WriteLine( "PanGestureRecognizer_Running" );
        var screenCoordinates = DependencyService.Get<ICommonDependent>().GetViewPositionInSuperView( layout, this.Content );
        inspectionViewModel.totalX = e.TotalX;
        inspectionViewModel.totalY = e.TotalY;


        Debug.WriteLine( "e.TotalX: " + e.TotalX + "e.TotalY: " + e.TotalY );
        double superViewX = screenCoordinates.x + inspectionViewModel.totalX;
        double superViewY = screenCoordinates.y + inspectionViewModel.totalY - layout.Height / 2;
        uxViolationMarkerImgView.IsVisible = true;

        Debug.WriteLine( $"x = {superViewX}, y = {superViewY}" );
        DisplayOnGoingMarkerAsView( superViewX, superViewY );
        break;

    case GestureStatus.Completed:
        // Store the translation applied during the pan
        Debug.WriteLine( "PanGestureRecognizer_Completed" );
        var lastScreenCoordinates = DependencyService.Get<ICommonDependent>().GetViewPositionInSuperView( layout, uxMapView );

        double mapViewX = lastScreenCoordinates.x + inspectionViewModel.totalX + layout.Width / 2;
        double mapViewY = lastScreenCoordinates.y + inspectionViewModel.totalY + layout.Height / 2;
        Debug.WriteLine( $"x = {mapViewX}, y = {mapViewY}" );

        uxViolationMarkerImgView.IsVisible = false;
        break;
    case GestureStatus.Canceled:
        Debug.WriteLine( "PanGestureRecognizer_Canceled" );
        uxViolationMarkerImgView.IsVisible = false;
        break;
    }
}

/*GetViewPositionInSuperView method to get child element position inside window*/

public ( double x, double y ) GetViewPositionInSuperView( Xamarin.Forms.View layout, Xamarin.Forms.View superview = null ) {
    var nativeView = Xamarin.Forms.Platform.UWP.Platform.GetRenderer( layout ).ContainerElement;
    FrameworkElement relativePositionView;
    if ( superview != null ) {
        relativePositionView = Xamarin.Forms.Platform.UWP.Platform.GetRenderer( superview ).ContainerElement;
    } else {
        relativePositionView = Window.Current.Content as Frame;
    }

    var element_Visual_Relative = nativeView.TransformToVisual( relativePositionView );
    ///element_Visual_Relative.TransformPoint(new Point(0, 0));

    Rect rectangle = element_Visual_Relative.TransformBounds( new Rect( new Point( nativeView.Margin.Left, nativeView.Margin.Top ), nativeView.RenderSize ) );

    Console.WriteLine( $"NativeX: {rectangle.X} NativeY: {rectangle.Y}" );
    return ( rectangle.X, rectangle.Y );
}

/*创建图像*/
void CreateImage（）{
var pangestruerecognizer=新的pangestruerecognizer（）；
pangestrerecognizer.PanUpdated+=pangestrerecognizer\u PanUpdated；
图像=新图像（）
{
HeightRequest=40，
宽度请求=40，
余量=新厚度（10,10,10,0），
Aspect=Aspect.AspectFit，
垂直选项=布局选项。开始，
Source=ImageSource.FromUri（新Uri（$“{codebookJSONModel.Violation.IconPath}”），
};
image.gestureignizers.Add（pangestureignizer）；
}
/*PanGesture更新事件*/
私有异步void PangestureRecognitor_PanUpdated（对象发送方，PanUpdatedEventArgs e）{
Console.WriteLine（“PangestureRecognitizer_PanUpdate”）；
变量布局=（图像）发送方；
开关（如状态类型）{
案例手势状态。已启动：
Console.WriteLine（“PangestureRecognitizer_启动”）；
inspectionViewModel.totalX=0；
inspectionViewModel.totalY=0；
打破
案例手势状态。正在运行：
//翻译并确保平移不会超出包装的用户界面元素边界。
Debug.WriteLine（“PangestureRecognitor_Running”）；
var screencordinates=DependencyService.Get（）.GetViewPositionInsPerView（布局，this.Content）；
inspectionViewModel.totalX=e.totalX；
inspectionViewModel.totalY=e.totalY；
Debug.WriteLine（“e.TotalX:+e.TotalX+”e.TotalY:+e.TotalY）；
双superViewX=屏幕坐标.x+检查视图模型.totalX；
双视图y=屏幕坐标.y+检查视图模型.totalY-布局.Height/2；
uxViolationMarkerImgView.IsVisible=true；
Debug.WriteLine（$“x={superViewX}，y={superViewY}”）；
显示OingOingMarkerasView（superViewX、superViewY）；
打破
案例管理状态。已完成：
//存储平移期间应用的平移
Debug.WriteLine（“PangestureRecognitizer_已完成”）；
var lastScreenCoordinates=DependencyService.Get（）.GetViewPositionInsPerView（布局，uxMapView）；
double mapViewX=lastScreenCoordinates.x+inspectionViewModel.totalX+layout.Width/2；
double mapViewY=lastScreenCoordinates.y+inspectionViewModel.Total+layout.Height/2；
Debug.WriteLine（$“x={mapViewX}，y={mapViewY}”）；
uxViolationMarkerImgView.IsVisible=false；
打破
案例手势状态。已取消：
Debug.WriteLine（“PangestureRecognitizer_已取消”）；
uxViolationMarkerImgView.IsVisible=false；
打破
}
}
/*获取窗口内子元素位置的GetViewPositionInsPerView方法*/
public（双x，双y）GetViewPositionInsPerView（Xamarin.Forms.View布局，Xamarin.Forms.View superview=null）{
var nativeView=Xamarin.Forms.Platform.UWP.Platform.GetRenderer（布局）.ContainerElement；
框架元素相对位置视图；
如果（superview！=null）{
relativePositionView=Xamarin.Forms.Platform.UWP.Platform.GetRenderer（superview）.ContainerElement；
}否则{
relativePositionView=Window.Current.Content作为框架；
}
var element_Visual_Relative=nativeView.TransformToVisual（relativePositionView）；
///元素可视相对转换点（新点（0,0））；
Rect rectangle=element_Visual_Relative.TransformBounds（新Rect（新点（nativeView.Margin.Left，nativeView.Margin.Top），nativeView.RenderSize））；
WriteLine（$“NativeX:{rectangle.X}NativeY:{rectangle.Y}”）；
返回值（矩形.X，矩形.Y）；
}

它只是在uwp中有问题吗？它在其他平台上只发射一次吗？它只是在uwp Xamarin.forms中发生的，在其他平台（如ios）上工作正常。