系统级滑动返回手势的屏蔽和开启
屏蔽滑动返回手势
self.navigationController.interactivePopGestureRecognizer.enabled = NO;
重新开启滑动返回手势
self.navigationController.interactivePopGestureRecognizer.enabled = YES;
屏蔽滑动返回手势
self.navigationController.interactivePopGestureRecognizer.enabled = NO;
重新开启滑动返回手势
self.navigationController.interactivePopGestureRecognizer.enabled = YES;