SuperMap.WinRT.Mapping.ElementsLayer.Draw C# (CSharp) Method

        internal override void Draw(UpdateParameter updateParameter)
        {
            if (base.Container != null)
            {
                Rectangle2D bounds = ViewBounds;
                double num = 20.0 * Resolution;
                Rectangle2D biggerBounds = bounds.Inflate(num, num);//上下左右扩张20个像素的距离
                foreach (UIElement element in this.Children)
                {
                    if (element == null)
                    {
                        return;
                    }
                    if (!(element.GetValue(BBoxProperty) is Rectangle2D))
                    {
                        throw new ArgumentException(ExceptionStrings.BboxIsNotSet);
                    }

                    Rectangle2D rect = GetBBox(element);
                    if (rect.IntersectsWith(biggerBounds) && !base.Container.Children.Contains(element))
                    {
                        if (element is ShapeElement)
                        {
                            ShapeElement sb = element as ShapeElement;
                            sb.SetPath();
                            sb.InvalidatePath(base.Container.Resolution, base.Container.OriginX, base.Container.OriginY);

                            ElementsLayer.SetBBox(sb, sb.ClippedBounds);
                        }
                        base.Container.Children.Add(element);
                    }
                }
            }
        }