什么时候rootViewController至tabbarController时刻,控制屏幕旋转法

于ios6后,ios系统改变了屏幕旋转的方法,假设您想将屏幕旋转法,在需求rootvc里面制备,例如

UIViewController *viewCtrl = [[UIViewController alloc] init];  
UINavigationController *navCtrl = [[UINavigationController alloc] initWithRootViewController:viewCtrl];  
if ([window respondsToSelector:@selector(setRootViewController:)]) {  
    self.window.rootViewController = navCtrl;  
} else {  
    [self.window addSubview:navCtrl.view];  
} 

UITabBarController+autoRotate

@interface UITabBarController (autoRotate)

-(BOOL)shouldAutorotate;
- (NSUInteger)supportedInterfaceOrientations;

@end


#import "UITabBarController+autoRotate.h"

@implementation UITabBarController (autoRotate)

- (BOOL)shouldAutorotate {
    return [self.selectedViewController shouldAutorotate];
}
- (NSUInteger)supportedInterfaceOrientations {
    return [self.selectedViewController supportedInterfaceOrientations];
}

@end

@interface UINavigationController (autoRotate)

-(BOOL)shouldAutorotate;
- (NSUInteger)supportedInterfaceOrientations;

@end

@implementation UINavigationController (autoRotate)

- (BOOL)shouldAutorotate {
    return [self.visibleViewController shouldAutorotate];
}

- (NSUInteger)supportedInterfaceOrientations {
    return [self.visibleViewController supportedInterfaceOrientations];
}

@end

UIViewController1.m

- (BOOL)shouldAutorotate {
    return NO;
}
- (NSUInteger)supportedInterfaceOrientations {
   return UIInterfaceOrientationMaskPortrait;;
}
UIViewController2.m

- (BOOL)shouldAutorotate {
   return YES;
}
- (NSUInteger)supportedInterfaceOrientations {
   return UIInterfaceOrientationMaskAll;
}

參考文章:IOS6屏幕旋转具体解释（自己主动旋转、手动旋转、兼容IOS6之前系统） , 在IOS应用中从竖屏模式强制转换为横屏模式 , http://stackoverflow.com/questions/12522903/uitabbarcontroller-rotation-issues-in-ios-6