Windows Phone 8檢查如果堆棧面板在可見區域

Question

這是一個非常簡單的問題。我有一個滾動視圖內的一些堆棧面板。我希望他們在用戶可見時（通過滾動）提出事件。

在此先感謝。

Answer 1

檢查this page了。它顯示如何確定您的元素是否在ScrollViewers視口中。

// position of your visual inside the scrollviewer  
GeneralTransform childTransform = ContainedObject.TransformToAncestor(ScrollViewerObj); 
Rect rectangle = childTransform.TransformBounds(new Rect(new Point(0,0),ContainedObject.RenderSize)); 

//Check if the elements Rect intersects with that of the scrollviewer's 
Rect result = Rect.Intersect(new Rect(new Point(0, 0), ScrollViewerObj.RenderSize),rectangle); 
//if result is Empty then the element is not in view 
if (result == Rect.Empty) 
{ 
//.... 
} 
else 
{ 
//obj is partially Or completely visible 
//skip or bring obj in view. 
}