#import <UIKit/UIKit.h>
#import <CoreMotion/CoreMotion.h>
//#import "NSString+Extension.h"

@interface ViewController : UIViewController
@property(nonatomic,strong)CMMotionManager *motionManager;
@end

判斷是否旋轉
給大家一個提示：commitAnimations記得在動畫結束之后一定要commit，因為這個錯誤導致整個程序都錯了，找了半天。

@implementation ViewController{
    CameraIconView *xiangCeIcon;
    CameraIconView *piaoJiaIcon;
    UILabel *directionPromptLabel1;
    UILabel *directionPromptLabel2;
}
- (void)viewDidLoad {
    [super viewDidLoad];
    [self startMotionManager];
}

-(void)startMotionManager{
    if (_motionManager == nil) {
        _motionManager = [[CMMotionManager alloc]init];
        
    }
    _motionManager.accelerometerUpdateInterval = 0.3;
    
    if (_motionManager.deviceMotionAvailable) {
        NSLog(@"Device Motion Available");
        [_motionManager startDeviceMotionUpdatesToQueue:[NSOperationQueue currentQueue]
                                            withHandler: ^(CMDeviceMotion *motion, NSError *error){
                                                [self performSelectorOnMainThread:@selector(handleDeviceMotion:) withObject:motion waitUntilDone:YES];
                                                
                                            }];
    } else {
        NSLog(@"No device motion on device.");
        [self setMotionManager:nil];
    }
    
    
}

-(void)handleDeviceMotion:(CMDeviceMotion *)deviceMotion{
    double x = deviceMotion.gravity.x;
    double y = deviceMotion.gravity.y;
    if (fabs(y) >= fabs(x))
    {
        NSLog(@"豎屏");
        if (y >= 0){
            // UIDeviceOrientationPortraitUpsideDown;home鍵在上
            [self fanzhuan:M_PI];
            
            directionPromptLabel1.hidden = YES;
            directionPromptLabel2.hidden = NO;
        }
        else{
            // UIDeviceOrientationPortrait；home鍵在下
            [self fanzhuan:M_PI *2];
            
            directionPromptLabel1.hidden = NO;
            directionPromptLabel2.hidden = YES;
        }
    
    }
    else
    {
        NSLog(@"橫屏");
        if (x >= 0){
            // UIDeviceOrientationLandscapeRight;//home鍵在右
            [self fanzhuan:-M_PI/2];
        }
        else{
            // UIDeviceOrientationLandscapeLeft;//home鍵在左
            [self fanzhuan:M_PI/2];
        }
        directionPromptLabel1.hidden = YES;
        directionPromptLabel2.hidden = NO;     
    }
    
}
-(void)fanzhuan:(CGFloat)angle{
    [CameraIconView beginAnimations:nil context:nil];
    [CameraIconView setAnimationDuration:0.5];
    
    CGAffineTransform transform = CGAffineTransformMakeRotation(angle);
    [_PhotoButton setTransform:transform];
    [xiangCeIcon setTransform:transform ];
    [piaoJiaIcon setTransform:transform ];
    
    [CameraIconView commitAnimations];
}

退出的時候關閉調用

-(void)viewDidDisappear:(BOOL)animated{
      [_motionManager stopDeviceMotionUpdates];
}