iOS手势:正常滑动时,一直调用- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event;
问题:使用iOS手势,按照正常来说,应该是首先调用了touchesbegain,结束时调用touchesend,只有发生系统事件时,才会调用touchesCancel,但是遇到一个问题就是,一直最开始就调用touchescancel,执行不到touchesend,所以调用不了方法.-(void)touchesBegan:(NSSet*)toucheswithEvent:(nullableUIEve