1、 UIScrollView里面嵌套两个tableView，右边一个tableView 又要实现左滑删除功能，写好左滑删除的代理方法，准备调试... 发现tableView左滑失效了，调试发现原来是UIScrollView的滑动手势和tableView的左滑手势冲突了。

2、写了一个继承UISrollView类 MyScrollView，在里面重写

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRequireFailureOfGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
  NSLog(@"_____%@______other:%@",gestureRecognizer,otherGestureRecognizer);
return NO;
}

（上面方法是UIGestureRecognizerDelegate有两个没公开的函数之一，只要重载了就会被调用，是可以通过appstore审核的）
调试输出发现 return NO会忽略otherGestureRecognizer 手势（被拦截） ；return YES则会调用 otherGestureRecognizer的方法（不拦截）；但是需求是cell左滑的手势可以执行，而不是所有的手势；单纯的return YES会造成UISrollView 无法左右滑动。

3、知道上面的的问题，那我们只需要判断 如果otherGestureRecognizer是cell左滑的手势 return yes 即可，其他return no。 通过调试打印发现

___<UIScrollViewPanGestureRecognizer: 0x138081870; state = Possible; delaysTouchesEnded = NO; view = <ANTScrollView 0x1370e9400>; target= <(action=handlePan:, target=<ANTScrollView 0x1370e9400>)>; must-fail = {
        <UIScrollViewPagingSwipeGestureRecognizer: 0x138014430; state = Failed; view = <ANTScrollView 0x1370e9400>; target= <(action=_handleSwipe:, target=<ANTScrollView 0x1370e9400>)>>
    }>______other:<UIScrollViewPanGestureRecognizer: 0x1380175c0; state = Possible; cancelsTouchesInView = NO; delaysTouchesEnded = NO; view = <UITableViewWrapperView 0x1370cec00>; targets= <(
    "(action=handlePan:, target=<UITableViewWrapperView 0x1370cec00>)",
    "(action=handleSwipeBeginning:, target=<UITableViewWrapperView 0x1370cec00>)"
)>>
2016-07-14 14:53:32.463 antQueen[7614:3034218] ___<UIScrollViewPanGestureRecognizer: 0x138081870; state = Possible; delaysTouchesEnded = NO; view = <ANTScrollView 0x1370e9400>; target= <(action=handlePan:, target=<ANTScrollView 0x1370e9400>)>; must-fail = {
        <UIScrollViewPagingSwipeGestureRecognizer: 0x138014430; state = Failed; view = <ANTScrollView 0x1370e9400>; target= <(action=_handleSwipe:, target=<ANTScrollView 0x1370e9400>)>>
    }>______other:<UIScrollViewDelayedTouchesBeganGestureRecognizer: 0x13807a5a0; state = Possible; delaysTouchesBegan = YES; view = <UITableView 0x13703f000>; target= <(action=delayed:, target=<UITableView 0x13703f000>)>>
2016-07-14 14:53:32.472 antQueen[7614:3034218] ___<UIScrollViewPanGestureRecognizer: 0x138081870; state = Possible; delaysTouchesEnded = NO; view = <ANTScrollView 0x1370e9400>; target= <(action=handlePan:, target=<ANTScrollView 0x1370e9400>)>; must-fail = {
        <UIScrollViewPagingSwipeGestureRecognizer: 0x138014430; state = Failed; view = <ANTScrollView 0x1370e9400>; target= <(action=_handleSwipe:, target=<ANTScrollView 0x1370e9400>)>>
    }>______other:<UIScrollViewDelayedTouchesBeganGestureRecognizer: 0x136db8360; state = Possible; delaysTouchesBegan = YES; view = <ANTScrollView 0x1370e9400>; target= <(action=delayed:, target=<ANTScrollView 0x1370e9400>)>>

我们发现其中有个UITableViewWrapperView这个就是我们要找的view，然后我们在方法里面做个判断：

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRequireFailureOfGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
    if ([otherGestureRecognizer.view isKindOfClass:NSClassFromString(@"UITableViewWrapperView")]) {
        return YES;
    }
    NSLog(@"_____%@______other:%@",gestureRecognizer,otherGestureRecognizer);
    return NO;
}

大功告成...调试发现cell可以实现左滑。

通过上面的私有方法，也可以去解决UIScrollView滑动与UINavigationVIewController的手势返回的冲突（自己研究下吧！）