Note for iOS7.0.

ky_iOS7_note.m

/* Status Bar
 *
 * Related threads:
 * - https://devforums.apple.com/message/867059#867059
 * - https://devforums.apple.com/thread/199395?start=0&tstart=0
 *
 * The relevant messages to override are:
 */
- (UIStatusBarStyle)preferredStatusBarStyle NS_AVAILABLE_IOS(7_0); // Defaults to UIStatusBarStyleDefault
- (BOOL)prefersStatusBarHidden NS_AVAILABLE_IOS(7_0); // Defaults to NO
- (UIStatusBarAnimation)preferredStatusBarUpdateAnimation NS_AVAILABLE_IOS(7_0); // Defaults to


/*
 * Layouts
 *
 * Related thread: https://devforums.apple.com/message/884707#884707
 */
NSMutableDictionary *views = ... // Some code here to add my views

// iOS 6 support - don't use top layout guide unless selector is present
NSString *topStr;
if ([self respondsToSelector:@selector(topLayoutGuide)]) {
  [views setValue:self.topLayoutGuide forKey:@"topLayoutGuide"];
  topStr = @"[topLayoutGuide]";
} else {
  topStr = @"|";
}

[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:[NSString stringWithFormat:@"V:%@-[mysubview]", topStr] options:0 metrics:nil views:views]];