如何将 viewControllers 放入循环数组中？

Question

我正在尝试使用自定义的选项卡视图控制器，用户可以在其中按照他/她喜欢的方式添加/重新排列它们。在下面的代码中我只需要返回数组计数并显示数组项，我设法通过数组的数量来完成，但是当它作为单个数组代码使用时，它只显示一个视图控制器！

代码如下：

class ContainerController: UITabBarController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let selectedViewControllers = [Home(),Index(),Favourite(),Library()]
        let selectedViewControllersProperties = ["Home","Index","Favourite","Library"]

        viewControllers = [createController(title: "\(selectedViewControllersProperties[0])".localized, imageName: "\(selectedViewControllersProperties[0])", vc: selectedViewControllers[0]),
        createController(title: "\(selectedViewControllersProperties[1])", imageName: "\(selectedViewControllersProperties[1])", vc: selectedViewControllers[1]),
        createController(title: "\(selectedViewControllersProperties[2])", imageName: "\(selectedViewControllersProperties[2])", vc: selectedViewControllers[2]),
        createController(title: "\(selectedViewControllersProperties[3])", imageName: "\(selectedViewControllersProperties[3])", vc: selectedViewControllers[3]),]
    }

    // MARK: - Handlers
    func createController(title: String, imageName: String, vc: UIViewController) -> UINavigationController{

        let recentVC = UINavigationController(rootViewController: vc)

        recentVC.tabBarItem.title = title
        recentVC.tabBarItem.image = UIImage(named: imageName)
        return recentVC
    }
}

当尝试使用这个数组时，它只显示一个 viewController：

let tabCount = selectedViewControllersProperties.count - 1

for i in 0...tabCount {
      viewControllers = [createController(title: "\(selectedViewControllersProperties[i])".localized, imageName: "\(selectedViewControllersProperties[i])", vc: selectedViewControllers[i])]
}

我在这里做错了什么，请帮助我解决它。

Answer 1

在 for 循环的每次迭代中，您只是将一个新数组（只有一项）设置为 viewControllers，这就是为什么 viewControllers 最后也只有一项。

您需要将append 新的VCs 加入到阵列中，而不是使用=：

let tabCount = selectedViewControllersProperties.count

// ..< is safer
var viewControllers = [] // you don't seem to have declared this beforehand.
for i in 0..<tabCount {
     viewControllers.append(createController(title: "\(selectedViewControllersProperties[i])".localized, imageName: "\(selectedViewControllersProperties[i])", vc: selectedViewControllers[i]))
}

您也可以使用map：

viewControllers = (0..<tabCount).map {
    createController(title: "\(selectedViewControllersProperties[$0])".localized, imageName: "\(selectedViewControllersProperties[$0])", vc: selectedViewControllers[$0])
}