如何在Windows Phone中居中彈出用戶控件？

Question

我想在屏幕中間彈出一個用戶控件，我該怎麼做？

Popup p = new Popup(); 
p.Child = new loadingtest(); 

    p.isOpen = true; 

Answer 1

var p = new Popup(); 
var content = new TextBox { Text = "hello world!" }; 
p.Child = content; 
p.VerticalOffset = (this.ActualHeight - content.ActualHeight)/2; 
p.HorizontalOffset = (this.ActualWidth - content.ActualWidth)/2; 
p.IsOpen = true; 

哪裏this是的PhoneApplicationPage和彈出是LayoutRoot電網的孩子。