未调用UISwipeGestureRecognizer选择器.知道为什么吗？

Question

我正在使用下面的代码将右/左滑动事件集成到UIImageView对象(称为photo_view),但在iphone模拟器和设备中进行测试后它无效.该方法handleLeftSwipe和handleRightSwipe以下,甚至没有所谓的日志记录没有在调试日志,它应该打印任何东西.这是代码:

- (void)viewDidLoad
{
     [super viewDidLoad];

     UISwipeGestureRecognizer *leftSwipeRecognizer = [[UISwipeGestureRecognizer alloc]  initWithTarget:self action:@selector(handleLeftSwipe:)];
     leftSwipeRecognizer.direction = UISwipeGestureRecognizerDirectionLeft;
     leftSwipeRecognizer.numberOfTouchesRequired = 1;
     [photo_view addGestureRecognizer:leftSwipeRecognizer];
     leftSwipeRecognizer.delegate = self;
     [leftSwipeRecognizer release];

     UISwipeGestureRecognizer *rightSwipeRecognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleRightSwipe:)];
     rightSwipeRecognizer.direction = UISwipeGestureRecognizerDirectionRight;
     rightSwipeRecognizer.numberOfTouchesRequired = 1;
     [photo_view addGestureRecognizer:rightSwipeRecognizer];
     rightSwipeRecognizer.delegate = self;
     [rightSwipeRecognizer release];

}


- (void)handleLeftSwipe:(UISwipeGestureRecognizer *)recognizer
{
     NSLog(@"handleLeftSwipe called");
}

- (void)handleRightSwipe:(UISwipeGestureRecognizer *)recognizer
{
     NSLog(@"handleRightSwipe called");
}

不知道是什么原因？

提前帮助,

斯特凡

Answer 1

UIImageView实例默认userInteractionEnabled为NO.尝试将其设置为YES.