OnWindowFocusChanged与OnCreate用于分配对象属性

Question

My question revolves around the onWindowFocusChanged method. I know that as a best practice, you should inflate your objects in the onCreate method.

What I'm wondering about is this: objects such as ImageViews are not completely rendered during the onCreate method. So you use onWindowFocusChanged, which the Android documentation says is called once the activity render is complete. I have ImageView objects that I need to get the X and Y positions for and (because of varying screen sizes) I won't know exactly where they are positioned on the screen unless I use hard coded numbers, which I don't want to do. I'll then assign margins for other ImageViews based on these X and Y numbers. But if I have to wait until onWindowFocusChanged to get X and Y, it doesn't do me any good to set those numbers in onCreate method.

So my question is - can I still set the properties of an ImageView inside of onWindowFocusChanged and have them re-rendered to their updated properties, or are the property values locked in because they've already been rendered?

Answer 1

Try by maintaining your View object inside the Activity class and calling postInvalidate() after the properties are set inside onWindowFocusChanged(). Hope it helps!