CGContext is being covered by a UIView

I'm not that great with Core Graphics, but I am drawing text on the screen to my CGContext. I am doing this immediately after I add a standard, 开发者_如何学Pythonopaque UIView to my user interface.

Does anyone know why the text I draw after I add my UIView is still at the "bottom" of the user interface?

Thanks in advance.

iOS, like OS X, uses a compositing window manager. Adding and removing UIViews sets their position in the view hierarchy; when and how they're drawn is managed separately. There is no guaranteed relation between when a view is added and when it'll be drawn, and no reason to guarantee one. The content of a view is cached and composited as required from that copy.

If you want to do custom drawing, create a custom UIView subclass, add it to the hierarchy according to where you want it to appear and do your drawing in drawRect: or one of the other override points if you want to render off thread.