问题:

Why do I see in some sample code from Apple (such as PhotoScroller) that I should do the following in loadView:

CGRect frame = [[UIScreen mainScreen] bounds];

instead of

CGRect frame = [[UIScreen mainScreen] applicationFrame];

Does it make a difference to get the main screen's frame?

回答1:

ApplicationFrame is the screen size minus the size of the status bar (if visible), bounds is the screen size regardless of status bar.

So applicationFrame would return CGRectMake(0,0,320,460) assuming your app has the status bar set to be visible, while bounds would return CGRectMake(0,0,320,480) under the same conditions. Those numbers are assuming iPhone/iPod Touch screen sizes.

UIScreen Class Reference

回答2:

iOS 9 Update

When using the Split View feature on the iPad, applicationFrame returns the size of your app window. bounds always returns the size of the device.