虽然这些答案解决了问题，但这可能是一些有用的

class MainNavigatioController: UINavigationController {

    override func pushViewController(_ viewController: UIViewController, animated: Bool) {
        // first
        let backItem = UIBarButtonItem()
        backItem.title = "رجوع"
        self.viewControllers.last?.navigationItem.backBarButtonItem = backItem
        // then
        super.pushViewController(viewController, animated: animated)

    }

}

Swift 4 -在按任何视图控制器之前配置后退按钮

// if you want to remove the text
navigationItem.backBarButtonItem = UIBarButtonItem()

// if you want to modify the text to "back"
navigationItem.backBarButtonItem = UIBarButtonItem(title: "back", style: .plain, target: nil, action: nil)

如果你正在为视图控制器使用xib文件，那么在你的视图控制器类中这样做。

class AboutUsViewController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()
    edgesForExtendedLayout = []
    setUpNavBar()
}

func setUpNavBar(){
    //For title in navigation bar
    self.navigationController?.view.backgroundColor = UIColor.white
    self.navigationController?.view.tintColor = UIColor.orange
    self.navigationItem.title = "About Us"

    //For back button in navigation bar
    let backButton = UIBarButtonItem()
    backButton.title = "Back"
    self.navigationController?.navigationBar.topItem?.backBarButtonItem = backButton
}

}

结果将是:

自我。标题= "" 之前self.navigationController ?。pushViewController(vc, animated: true)。

虽然这些答案解决了问题，但这可能是一些有用的

class MainNavigatioController: UINavigationController {

    override func pushViewController(_ viewController: UIViewController, animated: Bool) {
        // first
        let backItem = UIBarButtonItem()
        backItem.title = "رجوع"
        self.viewControllers.last?.navigationItem.backBarButtonItem = backItem
        // then
        super.pushViewController(viewController, animated: animated)

    }

}

后退按钮文本取自父视图控制器的导航项标题。所以无论你在前一个视图控制器的导航项标题上设置了什么，都会显示在当前视图控制器的后退按钮文本上。 你可以把""作为导航项标题在父视图控制器的viewWillAppear方法中。

self.navigationItem.title = ""

另一种方法是

self.navigationController?.navigationBar.topItem?.title = ""

在当前视图控制器的viewWillAppear方法中。如果导航堆栈嵌套过多，这将导致一些其他问题。