Question

我有多个屏幕，其中有textfield(s)。当用户在每个屏幕上下一个时，我想从他们那里收集数据。我试过的是：

MyViewController：

class MyViewController: UIViewController {

@IBOutlet weak var textField: UITextField!

var foo: MyModel = MyModel() // create instance of the model for the first time

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.destination is AnotherViewController {
        self.foo.column1 = textField.text ?? "" // update column1

        let vc = segue.destination as? AnotherViewController
        vc?.foo = self.foo // here, im passing the updated model
    }
}
}

AnotherViewController：

class AnotherViewController: UIViewController {

@IBOutlet weak var textField: UITextField!

var foo: MyModel! // model is constructed already, and passed with the updated data

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.destination is AnotherAgainViewController {
        self.foo.column2 = textField.text ?? "" // update column2

        let vc = segue.destination as? AnotherAgainViewController
        vc?.foo = self.foo // im passing again the updated model
    }
}
}

然后基本上，我一遍又一遍地重复这段代码。这在可维护性和灵活性方面是否可以？或者有更好的方法吗？

PS ：我不想仅使用单例来实现数据共享，因为这不是一个好习惯，难以调试（特别是当有人修改它时），并且会导致意大利面条代码。我希望以更清洁和可维护的方式实现这一目标。

Answer 1

使用基本控制器类并覆盖performSegueWithIdentifier：

class BaseController: UIViewController {

var foo: MyModel! // model is constructed already, and passed with the updated data

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.destination is AnotherAgainViewController {  // Replace if else by switch if you have many VC's
        let vc = segue.destination as? AnotherAgainViewController
        vc?.foo = self.foo
    }
}
}

现在在 MyViewController ：

class MyViewController: BaseController {

//
..
//  

// Wherever you are setting model  

self.foo = localModel    // self.foo is of BaseController

}

与其他ViewControllers类似。

Answer 2

通过对@Nitish代码的一些修改来管理：

<强> BaseController：

class BaseController: UIViewController {

var foo: MyModel!

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.destination is BaseController {
        let vc = segue.destination as? BaseController
        vc?.foo = self.foo
    }
}
}

<强> MyViewController：

class MyViewController: BaseController {

    @IBOutlet weak var textField: UITextField!

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        self.foo = Foo() // call initialization only on the first screen
        self.foo.column1 = foo.text ?? "" // update column1            
        super.prepare(for: segue, sender: sender) // call the super, and also this is flexible because I don't call specific view controller here.
    }
}

<强> AnotherViewController：

class AnotherViewController: BaseController {

    @IBOutlet weak var textField: UITextField!

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        self.foo.column2 = foo.text ?? "" // update column2            
        super.prepare(for: segue, sender: sender)
    }
}

跨屏幕收集数据的更快捷，更清晰的方式

2 个答案: