Question

我正在尝试使用可重用函数将数据从弹出式VC传递到父VC，以呈现弹出式窗口并获取结果。我尝试在弹出窗口中将闭包方法与函数变量一起使用，出现错误“ UIViewController没有成员'onSave'（函数变量）。任何帮助，将不胜感激。谢谢

我使用了委托和segues，但想避免使用，因此可以在弹出窗口中显示一个功能并收集许多实例的选择。

// Parent VC
class a2ExpenseAddViewController: UIViewController {
@IBAction func selectEtype(_ sender: Any) {
    popTitle = "Expense Types"//global var
    popMessage = "Select type below or add new" // global var
    menuPopup(choices: eTypes){ result in guard let result = else{
        return
        }
        self.eType.setTitle(result, for: .normal)        
    print("popChoice=",result)
    }
}

extension UIViewController { 

func menuPopup (choices: [String], completion: @escaping (_   choice: String?)  -> ()) {
let main = UIStoryboard(name: "Main", bundle: nil)
let goto = main.instantiateViewController(withIdentifier: "popup")
popChoices = choices
// Error below here - UIViewController has no member 'onSave'
goto.onSave = { (data: String) -> () in 
choice = data
}
self.present(goto, animated: true, completion: nil)
}

//Popup VC
PopupViewController: UIViewController,.. // storyboard id is 'popup'
var onSave: ((_ data: String) -> ())?

@IBAction func add(_ sender: Any) {
    popChoice = choice.text!
    onSave?(popChoice)
    dismiss(animated: true)    }

我希望通过onSave（data）将结果分配给按钮标题。我收到一个错误“ UIViewController没有成员'onSave'（函数变量）。

Answer 1

实例化后将ViewController设置为特定的类类型。

let goto = main.instantiateViewController(withIdentifier: "popup") as? PopupViewController

那么您应该可以做到

goto.onSave = { (data: String) -> () in 
choice = data
}

具有可重复使用的弹出式VC功能的数据传递

1 个答案: