Question

有三个场景

adminSignup(Parent) --> It has two text field country and city
countrySelectorView(Child of adminSignup) --> It has picker view to select country
citySelectorView(Child of adminSignup) --> It has picker view to select city

当单击adminSignup的国家/地区文本字段时，将调用countrySelectorView场景，用户将选择该国家/地区，然后它将返回到adminSignup场景，国家/地区值将传递给adminSignup。

但是当点击城市文本字段时，将调用countrySelectorView场景，用户将选择该国家/地区，然后它将返回到adminSignup场景，并且国家/地区值将传递给adminSignup并且国家/地区文本字段的值将被删除。

以下是adminSignUp的代码

override func viewDidLoad() {
    super.viewDidLoad()
    if let passedCityValue = cityValue {
        cityTextFeild.text = passedCityValue
    }
    if let currentCountryValue = countryValue {
       countryTextFeild.text = currentCountryValue
    }
}

以下是countrySelectorView的代码

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    guard  let instanceOfAdminSignUp = segue.destination as? adminSignUp else {    return    }
    instanceOfAdminSignUp.countryValue = countryValue
}

以下是citySelectorView的代码

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    guard let instanceOfAdminSignUp = segue.destination as? adminSignUp else { return }
    instanceOfAdminSignUp.cityValue = cityValue
}

Answer 1

请按照以下步骤

1- adminSignup查看控制器：

使用委托设计模式进行2个ViewControllers之间的通信

protocol AdminSignUPDelegate: class {
   func cityValuePicked(value: String)
   func countryValuePicked(value: String)
}

extension adminSignUp: AdminSignUPDelegate {

    func cityValuePicked(value: String) {
         cityTextFeild.text = value
    }
    func countryValuePicked(value: String) {
        countryTextFeild.text = value
    }

}

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if let destinationViewController = segue.destination as? countrySelectorController {
        destinationViewController.delegate = self
    }
    if let destinationViewController = segue.destination as? citySelectorController {
        destinationViewController.delegate = self
    }
}

2-城市选择ViewController

// Property
var delegate: AdminSignUPDelegate?

@IBAction func btnOKPressed(_ sender: Any) {
    delegate?.cityValuePicked(value: cityValue)
    dismiss(animated: true, completion: nil)
}

3-国家选择ViewController

    // Property
var delegate: AdminSignUPDelegate?

@IBAction func btnOKPressed(_ sender: Any) {

    delegate?.countryValuePicked(value: countryValue)
    dismiss(animated: true, completion: nil)
}

注意：从国家/地区删除Segue＆amp;城市视图控制器到父级

如何从这里下载代码的工作示例

https://drive.google.com/file/d/1lA5ewSvw6KGyLW4XKQm10wSDE9dl_2PB/view?usp=sharing

成功加载视图后，文本字段数据将被删除

1 个答案: