iOS 隐藏导航栏，出现一闪问题解决

问题：self.navigationController隐藏导航栏返回上一层，使用方法为

- (void)viewWillAppear:(BOOL)animated{   

[superviewWillAppear:animated];

self.navigationController.navigationBar.hidden = YES;

}

- (void)viewWillDisappear:(BOOL)animated {

[super viewWillDisappear:animated];

self.navigationController.navigationBar.hidden = NO;

}

会出现返回上一层一闪的情况。

解决：

用如下方法代替

    [self.navigationController setNavigationBarHidden:YES animated:YES];

    [self.navigationController setNavigationBarHidden:NO animated:YES];