- (void)viewDidLoad {    [super viewDidLoad];    [[UIApplication sharedApplication] setApplicationSupportsShakeToEdit:YES];//设置摇一摇时是否支持redo和undo操作，缺省时为yes，所以这句可以不写    [self becomeFirstResponder];//将当前控制器设置为第一响应者，只有第一响应者能够响应摇一摇的触发事件}//开始摇一摇时的响应方法- (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event {    NSLog(@"开始摇一摇");}//取消摇一摇时的响应方法（例如有电话打进来取消了摇一摇）- (void)motionCancelled:(UIEventSubtype)motion withEvent:(UIEvent *)event {    NSLog(@"取消摇一摇");}//摇一摇结束时的响应方法- (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event {    if (motion != UIEventSubtypeMotionShake) {
   //判断手势是否是晃动手势        return;    }    self.view.backgroundColor = [UIColor redColor];    NSLog(@"摇一摇结束");}