单个APP页面支持屏幕旋转

1、info中支持所有的方向

2、APPDelega.h中添加属性

@property (nonatomic,assign) BOOL allowRotate;

APPdelegate.m中实现方法

//此方法会在设备横竖屏变化的时候调用
- (UIInterfaceOrientationMask)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window {
    if (_allowRotate) {
        return UIInterfaceOrientationMaskAll;
    }else{
        return UIInterfaceOrientationMaskPortrait;
    }
}

3、在需要旋转的单个页面中添加

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    AppDelegate * delegate = (AppDelegate *)[UIApplication sharedApplication].delegate;
    delegate.allowRotate = YES;
}

- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    AppDelegate * delegate = (AppDelegate *)[UIApplication sharedApplication].delegate;
    delegate.allowRotate = NO;

    if ([[UIDevice currentDevice] respondsToSelector:@selector(setOrientation:)]){
        SEL selector = NSSelectorFromString(@"setOrientation:");
        NSInvocation * invocation = [NSInvocation invocationWithMethodSignature:[UIDevice instanceMethodSignatureForSelector:selector]];
        [invocation setSelector:selector];
        [invocation setTarget:[UIDevice currentDevice]];
        int val = UIInterfaceOrientationPortrait;
        [invocation setArgument:&val atIndex:];
        [invocation invoke];
    }
}

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
    if (toInterfaceOrientation == UIInterfaceOrientationLandscapeLeft || toInterfaceOrientation == UIInterfaceOrientationLandscapeRight) {
//        屏幕从竖屏变为横屏时执行
        NSLog(@"屏幕从竖屏变为横屏");

    }else{
//        屏幕从横屏变为竖屏时执行
        NSLog(@"屏幕从横屏变为竖屏");
    }
}

- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
    // do something after rotation

}

后话

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(orientChange:) name:UIDeviceOrientationDidChangeNotification object:[UIDevice currentDevice]];

- (void)orientChange:(NSNotification *)notification {
    UIDeviceOrientation orientation = [UIDevice currentDevice].orientation;
    if (orientation == UIDeviceOrientationLandscapeLeft) {
        NSLog(@"notification: 屏幕从竖屏变为横屏");
    } else if (orientation == UIDeviceOrientationLandscapeRight) {
        NSLog(@"notification: 屏幕从竖屏变为横屏");
    } else if (orientation == UIDeviceOrientationPortrait) {
        NSLog(@"notification: 屏幕从横屏变为竖屏");
    }
}