ios - 无法将 UIBarButtonItem 添加到 UITabBarController 内的 navigationController

Question

ViewController *VC = [[ViewController alloc] initWithNibName:nil bundle:nil];
UINavigationController *NavCon = [[UINavigationController alloc] initWithRootViewController:VC];
NavCon.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Close" style:UIBarButtonItemStyleBordered target:self action:@selector(showall)];
[self.myTabBarController setViewControllers:@[NavCon]];

为什么它没有将 UIBarButtonItem 添加到我的导航 Controller ？

Answer 1

首先删除/注释代码行

NavCon.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Close" style:UIBarButtonItemStyleBordered target:self action:@selector(showall)];

然后将此代码放入 navController 的 viewController 的 viewDidLoad 方法中。

self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Close" style:UIBarButtonItemStyleBordered target:self action:@selector(showall)];