ios - prepareForSegue 函数不起作用

Question

我确定我有两个 View Controller ，它们有适当的文件作为它们的类。 (ViewController1.swift 和 ViewController2.swift)我试图使用以下代码将数据从一个 View Controller 传递到另一个 View Controller ；但我收到错误“UIView Controller is not conversionble to ViewController2”。我应该怎么办？我试图改变至于!和 var 来让；都不起作用。

   override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!){

        if (segue.identifier == "btnSubmitSegue") {
        var svc = segue.destinationViewController as ViewController2;
        svc.DataPassed = textField.text

    }
}

ViewController2 的代码 导入 UIKit

 class ViewController2: UIViewController {

var toPass: String = ""
 @IBOutlet weak var labeld: UILabel!



override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

      self.labeld.text = "passed: \(self.toPass)"

}




override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
  }
}

ViewController1 的代码

  import UIKit

  class ViewController1: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}



@IBOutlet weak var textField: UITextField!

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {

    if segue.identifier == "TheSegue" {
        let vc = segue.destinationViewController as! ViewController2
        vc.toPass = self.textField.text!
    }
  }


}

Answer 1

以下示例对我来说效果很好。第一个 View Controller 的代码:

class ViewController: UIViewController {

    @IBOutlet weak var textField: UITextField!

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {

        if segue.identifier == "TheSegue" {
            let vc = segue.destinationViewController as! ViewController2
            vc.passedText = self.textField.text!
        }
    }
}

在第二个 View Controller 中:

    class ViewController2: UIViewController {
        var passedText: String = ""
        @IBOutlet weak var label: UILabel!

        override func viewDidLoad() {
            super.viewDidLoad()
            self.label.text = "passed: \(self.passedText)"
        }
    }

不要忘记在 Storyboard 中命名 segue:

您的目标 View Controller 引用了错误的 Controller 。你应该在你的代码中有这个，而不是 as! ViewController1:

let vc = segue.destinationViewController as! ViewController2

还需要修改你的IBOutlet名称，vc.toPass = self.textField.text!应该是:

vc.toPass = self.labeld.text!

确保为第二个 View Controller 设置自定义类: