使用obj-c的UINavigationController居中按钮

// 创建自定义按钮
UIButton *centerButton = [UIButton buttonWithType:UIButtonTypeCustom];
[centerButton setTitle:@"Center" forState:UIControlStateNormal];
[centerButton addTarget:self action:@selector(centerButtonTapped) forControlEvents:UIControlEventTouchUpInside];
[centerButton sizeToFit];

// 创建自定义UIBarButtonItem
UIBarButtonItem *centerButtonItem = [[UIBarButtonItem alloc] initWithCustomView:centerButton];

// 获取当前视图控制器的UINavigationItem
UINavigationItem *currentNavItem = self.navigationController.topViewController.navigationItem;

// 设置居中按钮
currentNavItem.center = centerButtonItem;

// 导航到下一个视图控制器
UIViewController *nextViewController = [[UIViewController alloc] init];
[self.navigationController pushViewController:nextViewController animated:YES];