ios - 如何更改 UINavigationController Title & backButton 编程？

Question

我有两个 View Controller 。

vc1 -> presentVC -> vc2

vc2继承UINavigationController

我想在 vc2 中设置 title 和 backButton，但是它不起作用。

class vc2: UINavigationController {

override func viewDidLoad() {
    super.viewDidLoad()

    // set title!!!
    //self.navigationItem.title = "123"
    //self.navigationController?.navigationBar.topItem?.title = "123"
    //self.title = "123"
    //self.navigationBar.topItem?.title = "123"
    //self.navigationItem.title = "123"

    // set backButton!!!
    let navButtonWidth:CGFloat = 44
    let backButton:UIButton = UIButton()
    backButton.setImage(backImage, for: .normal)
    backButton.addTarget(self, action: #selector(back), for: .touchUpInside)
    self.navigationItem.leftBarButtonItems = [UIBarButtonItem(customView: backButton)]

}

Answer 1

将下面的代码放在 perform(segue) 或 viewWillDissappear 中，具体取决于您如何进行演示 - 通过 Storyboard segue 或手动从代码。

let backButton = UIBarButtonItem()
backButton.title = "whatever_you_want"
navigationItem.backBarButtonItem = backButton

并且在你的vc2的viewDidLoad中简单的说

navigationItem.title = "Controller title"