Question

import UIKit

class ViewController: UIViewController {

@IBOutlet weak var username: UITextField!

@IBAction func loginPressed(_ sender: Any) {

    print("Username entered is  \(username.text)")

    let displayViewController = storyboard?.instantiateViewController(withIdentifier: "DisplayViewController") as! DisplayViewController

    displayViewController.usernameEntered = username.text

    self.navigationController?.pushViewController(displayViewController, animated: true)

}

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.
}
}

我试图传输这些数据＆＃34;用户名＆＃34;到另一个视图控制器。我的大部分工作正常，但displayViewController.usernameEntered = username.text

上有断点错误

以下是我的其他视图控制器的代码：

import UIKit

class DisplayViewController: UIViewController {

var usernameEntered:String?

@IBOutlet weak var usernameLabel: UILabel!


override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.
}

override func viewDidAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    if let usernameToDisplay = usernameEntered
    {
        self.usernameLabel.text = usernameToDisplay
    }

}

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

}

对于为什么会发生这种情况的任何见解将不胜感激！

Answer 1

检查username.text不应该是nil

＆安培;确保您已从故事板中连接usernameEntered标签插座。

尝试开始从一个viewcontroller到另一个viewcontroller的数据传输时获取断点错误

1 个答案: