ios - 在 UINavigationBar 中隐藏或禁用 UIBarButtonItem

Question

我正在展示一个带有模态转场的 UIViewController。这个 UIViewController 继承了一个 UINavigationBar，我在导航栏的左侧设置了一个 UIBarButtonItem:

我的问题是，当调用呈现的 UIViewController 的 viewWillAppear 方法时，我试图隐藏 UIBarButtonItem，但 UIBarButtonItem 总是出现。我已经为 UIViewController 声明了一个 UIBarButtonItem，名为 myCancelButton，并且我在 Interface Builder 中引用了它。

这是我到目前为止尝试过的方法(所有这些都不起作用):

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

    self.navigationItem.leftBarButtonItem = nil;
    self.navigationItem.backBarButtonItem = nil;
    self.myCancelButton = nil;

    NSMutableArray *barButtonItems = [self.navigationItem.leftBarButtonItems mutableCopy];
    [barButtonItems removeObject:self.myCancelButton];
    self.navigationItem.leftBarButtonItems = barButtonItems;

    [self.navigationItem.leftBarButtonItems delete:self.myCancelButton];

    self.navigationController.navigationItem.leftBarButtonItem = nil;
    barButtonItems = [self.navigationController.navigationItem.leftBarButtonItems mutableCopy];
    [barButtonItems removeObject:self.myCancelButton];
    self.navigationController.navigationItem.leftBarButtonItems = barButtonItems;

    [self.navigationController.navigationItem.leftBarButtonItems delete:self.myCancelButton];

    [self.myCancelButton setWidth:0.01];

    self.navigationItem.hidesBackButton = TRUE;

    //Even setting enabled to false doesn't work:
    [self.myCancelButton setEnabled:FALSE];
}

Answer 1

这应该有效。

[self.navigationItem setHidesBackButton:YES animated:YES];