On iOS, why does height of a view's frame remain almost the same after rotation?

Question

In ViewController.m, on an iPad, if we print out the view's frame height in a tap event handler:

NSLog(@"Height of main view is %f", self.view.frame.size.height);

then in Portrait mode, the value is 1004 (20 pixel for device status line, so 1024 - 20 = 1004), and if the device is rotated to Landscape mode, I expected it to be about 768 or 748, but the value printed is actually 1024. (update: if the app is started in Landscape mode, then without rotation, it is also printed as 1024). Why would that be, and is there a rule of thumb to expect getting the value of 748 or 768? (Is there more than one way to get that?)

Answer 1

In Apple's documents, about UIView's frame:

Warning: If the transform property is not the identity transform, the value of this property is undefined and therefore should be ignored.

So you should use bounds property.