要实现UIScrollView上获取touchesBegan事件 其实并不难，我们在UIscrollView里面加一个类扩展，传递给上一级即可，具体实现如下
@implementation UIScrollView (UITouch)// 让touchesBegan传递下去- (void)touchesBegan:(NSSet*)touches withEvent:(UIEvent *)event
{
// 选其一即可
[super touchesBegan:touches withEvent:event];
// [[self nextResponder] touchesBegan:touches withEvent:event];
}
