public void AddTouchMoveHandler(Xamarin.Forms.VisualElement xamarinVisual, EventHandler <TouchEventArgs> handler)
{
IVisualElementRenderer renderer = Platform.GetRenderer(xamarinVisual);
Panel panel = renderer as Panel;
panel.PointerMoved += this.Panel_PointerMoved;
TouchEventsHelper helper = GetOrCreateTouchEventsHelper(panel);
helper.touchMoveHandlers.Add(handler);
}
private void Panel_PointerMoved(object sender, PointerRoutedEventArgs e)
{
UIElement uiElement = (UIElement)sender;
PointerPoint pointer = e.GetCurrentPoint(uiElement);
TouchEventsHelper helper = GetOrCreateTouchEventsHelper(uiElement);
TouchEventArgs args = new TouchEventArgs(new Xamarin.Forms.Point(pointer.Position.X, pointer.Position.Y));
foreach (var handler in helper.touchMoveHandlers)
{
handler(null, args);
}
}
private static TouchEventsHelper GetOrCreateTouchEventsHelper(DependencyObject obj)
{
TouchEventsHelper helper = (TouchEventsHelper)obj.GetValue(TouchEventsHelperProperty);
if (helper == null)
{
helper = new TouchEventsHelper();
obj.SetValue(TouchEventsHelperProperty, helper);
}
return(helper);
}
