iOS7 hide status bar but not adjust top layout guide

问题

I deal with autolayout set up in Interface Builder. I want to not offset views that are pinned to top layout guide when I hide status bar in runtime.

I have discovered that myViewController.topLayoutGuide.length changes from 20 to 0 when hiding status bar. How to prevent it? Or (as workaround) how to set up fullscreen view for various window sizes without pin to top layout guide?

Some code to describe my situation:

Log(@"frame: %@, top: %.0f", NSStringFromCGRect(myViewController.myView.frame), self.topLayoutGuide.length);
[[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation:UIStatusBarAnimationNone];
Log(@"frame: %@, top: %.0f", NSStringFromCGRect(myViewController.myView.frame), self.topLayoutGuide.length);

Output:

frame: {{40, 24}, {240, 40}}, top: 20
frame: {{40, 4}, {240, 40}}, top: 0

回答1:

The topLayoutGuide property is readonly and you can't prevent it from changing.

You can pin your items not to the topLayoutGuide but to the superview. That should resolve your problem.

来源：https://stackoverflow.com/questions/21756350/ios7-hide-status-bar-but-not-adjust-top-layout-guide