隐藏或禁用UINavigationBar中的UIBarButtonItem

Question

我正在用模态塞格展示UIViewController。 这UIViewController中继承了一个UINavigationBar的，我已经设置的UIBarButtonItem左侧导航栏：

我的问题是，当呈现的UIViewController的viewWillAppear中调用方法，我想隐藏UIBarButtonItem，但总是出现UIBarButtonItem。 我已经为UIViewController声明了一个名为myCancelButton的UIBarButtonItem，并且我在Interface Builder中引用了它。

这是我到目前为止已经试过（全部不工作）：

- (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

这应该工作。

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

Answer 2

尝试不幸的是使用一个

self.navigationController.navigationItem.leftBarButtonItem = nil; 
[self.navigationController.navigationItem setHidesBackButton:YES];