UIBarButtonItem删除后退按钮标题 - iOS 11

Question

    UIBarButtonItem.appearance().setBackButtonTitlePositionAdjustment(UIOffsetMake(0, -60), for:UIBarMetrics.default)

我在上面使用它来移除iOS 11之前的backButtonTitle但是在iOS 11上没有正常工作。 箭头向下移动。 如何解决这个问题？

编辑：通过删除标题的其他方式可以解决我的问题，但我担心的是为什么旧方法不再起作用。

Answer 1

另一种方法是为navigationController设置<<<<<<< HEAD ... ======= ... >>>>>>> master 并删除其功能中的标题。

UINavigationControllerDelegate

Answer 2

使用此代码，

drop table if exists enrolledtable;
drop table if exists coursetable;
drop table if exists studenttable;

CREATE TABLE studenttable(
nickname VARCHAR(45),
pass VARCHAR(45),
PRIMARY KEY (nickname)
);

CREATE TABLE coursetable(
subject VARCHAR(45),
course VARCHAR(45),
cname VARCHAR(45),
credit INT,
PRIMARY KEY (subject, course),
key k1 (course)                     #added
);

CREATE TABLE enrolledtable (
nickname VARCHAR(45),
subject VARCHAR(45),
course VARCHAR(45),
PRIMARY KEY (nickname, subject, course),
FOREIGN KEY (nickname) REFERENCES studenttable (nickname),
FOREIGN KEY (subject) REFERENCES coursetable (subject),
FOREIGN KEY (course) REFERENCES coursetable (course)
);

Answer 3

创建导航控制器类，如下所示。分配这个＆＃34; CustomNavViewController＆＃34;到你的StoryBoard中的UINavigationController

class CustomNavViewController: UINavigationController,UINavigationControllerDelegate 
{


override func viewDidLoad() {
    super.viewDidLoad()

    self.delegate = self
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}


func navigationController(
    _ navigationController: UINavigationController,
    willShow viewController: UIViewController,
    animated: Bool
    ) {
    viewController.navigationItem.backBarButtonItem = UIBarButtonItem(title: " ", style: .plain, target: nil, action: nil)
}

}

因此，无需在每个viewControllers中执行此操作。 最后从AppDelegate类中移除以下行，如果存在，

UIBarButtonItem.appearance().setBackButtonTitlePositionAdjustment(UIOffsetMake(0, -60), for:UIBarMetrics.default)

Answer 4

不是垂直移动标题，而是可以水平移动。如果标题很长，你可以使它的颜色透明。工作得很好我：

let barButtonItemAppearance = UIBarButtonItem.appearance()
    barButtonItemAppearance.setTitleTextAttributes([NSAttributedStringKey.foregroundColor: UIColor.clear], for: .normal)
    barButtonItemAppearance.setBackButtonTitlePositionAdjustment(UIOffsetMake(-200, 0), for:UIBarMetrics.default)