实现多个手势同时执行

ios开发中，默认是在同一时间只能有一个手势被执行，要实现多个手势同时进行，须实现 UIGestureRecognizerDelegate，并重写函数

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

以Pinch和Rotation手势为例，首先是添加手势：

        UIGestureRecognizer *recognizer;
 recognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(handleRotationFrom:)];
 recognizer.cancelsTouchesInView = NO;
 recognizer.delegate = self;
 [self.view addGestureRecognizer:recognizer];
 [recognizer release];

 UIGestureRecognizer *recognizer2;
 recognizer2 = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinch:)];
 recognizer2.cancelsTouchesInView = NO;
 recognizer2.delegate = self;
 [self.view addGestureRecognizer:recognizer2];
 [recognizer2 release];

接着重写上面提到的函数，只需返回YES即可。

 - (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer

   shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer

 return YES;