获取使用故事板创建的 viewcontroller 的属性

Question

我目前正在学习 swift 并且我正在尝试从故事板作品中学习实例化，但是我现在面临的错误并没有太多记录。

我在主情节提要中创建了一个 viewcontroller 并将其指定为自定义类型 class 我之前调用过 SimpleNewsViewController，这是我的class的代码，并不复杂：

class SimpleNewsViewController: UIViewController {

@IBOutlet weak var myImage: UIImageView!
@IBOutlet weak var myLabel: UILabel!
@IBOutlet weak var myText: UITextView!

var event: Events!

override func viewDidLoad() {
    super.viewDidLoad()
}

}

在我的主要故事板上，这里是我指定的自定义 ViewController： My Storyboard implementation

现在的问题是：在我的代码中，我实例化了我的 ViewController 感谢 instanciateViewController(identifier: "NewsView") 然后我尝试设置我的 3 个属性，如这段代码：

...
    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let controller = storyboard.instantiateViewController(withIdentifier: "NewsView") as! SimpleNewsViewController
    //controller.myImage.image = UIImage(named: "image.jpg")
    //controller.myText.text = "this is an example that can be really long"
    //controller.myTitle.text = "this is a title example
    self.navigationController?.pushViewController(controller, animated: true)
...

如果我取消对这三行的注释，我会收到一条错误消息：

Fatal error: Unexpectedly found nil while unwrapping an Optional value

IDE 还显示错误代码和线程（如果有帮助的话）： The error

Answer 1

在实例化控制器后插座尚未连接，您必须声明临时变量并在 viewDidLoad()

中设置插座属性

...
    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let controller = storyboard.instantiateViewController(withIdentifier: "NewsView") as! SimpleNewsViewController
    controller.tempImage = UIImage(named: "image.jpg")
    controller.tempLabel = "this is an example that can be really long"
    controller.tempText = "this is a title example
    self.navigationController?.pushViewController(controller, animated: true)
...

class SimpleNewsViewController: UIViewController {

@IBOutlet weak var myImage: UIImageView!
@IBOutlet weak var myLabel: UILabel!
@IBOutlet weak var myText: UITextView!

var tempImage : UIImage?
var tempLabel = ""
var tempText = ""

var event: Events!

override func viewDidLoad() {
    super.viewDidLoad()
    myImage.image = tempImage
    myLabel.text = tempLabel
    tempText.text = tempText
}

获取使用故事板创建的 viewcontroller 的属性

Get attribute of viewcontroller created with storyboard

ios

swift3

viewcontroller

xcode-storyboard