ios - setNeedsLayout 和 setNeedsDisplay

Question

UIView 方法 setNeedsLayout 和 setNeedsDisplay 之间的真正区别是什么？

像往常一样，文档对此模糊不清。

Answer 1

实际上文档对此很清楚:

• setNeedsLayout将布局 subview

  Call this method on your application’s main thread when you want to adjust the layout of a view’s subviews.

• setNeedsDisplay将要求重绘您的 View (drawRect: 等)。

  You can use this method or the setNeedsDisplayInRect: to notify the system that your view’s contents need to be redrawn.