2015-10-27--手势优先级

如果一张图片既要单击手势， 又要双击手势，要怎么处理，看完这句代码你就知道了

UITapGestureRecognizer*doubleRecognizer = [[UITapGestureRecognizeralloc]initWithTarget:selfaction:@selector(handleDoubleTapGesture:)];

doubleRecognizer.numberOfTapsRequired=2;

[_containerViewaddGestureRecognizer:doubleRecognizer];

UITapGestureRecognizer*singleRecognizer = [[UITapGestureRecognizeralloc]initWithTarget:selfaction:@selector(handleTapGesture:)];

[_containerViewaddGestureRecognizer:singleRecognizer];

[singleRecognizerrequireGestureRecognizerToFail:doubleRecognizer];

单击事件的执行依赖于双击事件失败的基础上，如果不加这句依赖关系，双击两次的时候，只会执行两次单击事件，永远不会执行双击事件。这个依赖关系只适用于同一个控制器，若是在不同的控制器，可使用下面的代理设置优先级

- (BOOL)gestureRecognizer:(UIGestureRecognizer*)gestureRecognizer shouldRequireFailureOfGestureRecognizer:(UIGestureRecognizer*)otherGestureRecognizer

{

}

- (BOOL)gestureRecognizer:(UIGestureRecognizer*)gestureRecognizer shouldBeRequiredToFailByGestureRecognizer:(UIGestureRecognizer*)otherGestureRecognizer

{

}