iphone - 为什么 setBackBarButtonItem 在 childViewController viewDIdLoad 中不起作用？

Question

我想在navigationItem中自定义backBarButtonItem，这是我的代码

- (void)viewDidLoad
{
    [super viewDidLoad];

    UIBarButtonItem *back = [[UIBarButtonItem alloc] initWithTitle:@"Back"
                                                             style:UIBarButtonItemStylePlain
                                                            target:nil
                                                            action:nil];
    [[self navigationItem] setBackBarButtonItem:back];
}

但是当我使用 leftBarButtionItem 时它不起作用。

我不知道，谁能给我一个答案？

Answer 1

- (void)viewDidLoad
{
    [self.navigationItem setHidesBackButton:YES];

    UIBarButtonItem *cancelNavButton = [[UIBarButtonItem alloc] initWithTitle:@"Cancel" style:UIBarButtonItemStylePlain target:self action:@selector(dismissController)];
    [self.navigationItem setLeftBarButtonItem:cancelNavButton];
}

- (void)dismissController
{
    [self.navigationController popViewControllerAnimated:YES];
}