更改Xamarin表单中的TranslationX属性会导致UIKit一致性异常

Question

从自定义渲染器调用共享代码类以更新触摸Xamarin的移动时会抛出此异常：

Application.DisplayAlerts = True

此处生成错误的代码：

iOS渲染器：

UIKit Consistency error: you are calling a UIKit method that can only be invoked from the UI thread.

共享班级

[assembly: ExportRenderer (typeof (CustomTabbedPage), typeof (CustomTabbedPageRenderer))]

namespace CustomRenderer.iOS
{
    public class CustomTabbedPageRenderer : PageRenderer
    {
        ...
        public override void TouchesMoved(NSSet touches, UIEvent evt)
        {
            ...

            ((CustomTabbedPage)this.Element).updateDragDelta( (double) ( _touchMovedToPoint.X - _touchStartingPoint.X ));

        }

     }

}

堆栈跟踪：

namespace CompanyName
{   
    public class CustomTabbedPage : BaseContentPage
    {
            ...

            public void updateDragDelta(double x)
             {
                 Device.BeginInvokeOnMainThread (() => {
                     dragDeltaX = x;
                     this.TranslationX = _lockPosition + dragDeltaX;
                  });
             }
    }
}

我正在尝试让共享代码类知道触摸移动到的位置。值得注意的是CustomTabbedPageRenderer类还有两个UISwipeGestureRecognizer。