View 转换时 iOS 7 UINavigationBar 未隐藏

Question

我有像 vc1 -> vc2 -> vc1 这样的 View Controller 转换。我需要将 UINavigationBar 隐藏在 vc1 中，并在 vc2 中显示。

我做了以下事情:

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

    self.navigationController.navigationBarHidden = YES;
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];

    self.navigationController.navigationBarHidden = NO;
}

在 iOS6 中，它工作正常。但是在iOS7中，当我从vc1回到vc2时，导航栏并没有被隐藏，而是向上移动到状态栏后面，过渡动画结束后导航栏被隐藏了。

我怎样才能真正隐藏导航栏？

Answer 1

像这样尝试:

-(void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    [self.navigationController setNavigationBarHidden:YES];  
}

-(void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];

    [self.navigationController setNavigationBarHidden:NO]; 
}

或者这样尝试:

- (void)viewWillAppear:(BOOL)animated
{
    [self.navigationController setNavigationBarHidden:YES animated:animated];
    [super viewWillAppear:animated];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [self.navigationController setNavigationBarHidden:NO animated:animated];
    [super viewWillDisappear:animated];
}