Question

我正在学习授权的概念，我被困在我的项目中。我相信解决方案很简单，但是这对我来说是新的，我不知道出了什么问题。

项目概念很简单：
应用程序中有两个视图。在第一个视图中，按下按钮＆＃34;更改颜色＆＃34;结果出现第二个视图。在第二个视图中，有三个文本字段，其中用户分别为RGB颜色的R G和B值放置数字。当点击按钮时，第二视图消失，并且应该根据用户的输入用颜色改变第一视图的背景。我假设用户输入正确的数字，因此此时我使用强制解包这些值此时视图显示正确，但第一个视图的背景颜色不会改变，我不知道为什么。

Beneath是两个视图控制器的代码。我会很感激任何提示。

第一个VC：ViewController.swift

class ViewController: UIViewController, ColorChangeDelegate {

let secondStoryboard = UIStoryboard(name: "Second", bundle: nil).instantiateViewControllerWithIdentifier("SecondViewController") as UIViewController
var secondVC = SecondViewController()


@IBAction func changeColourButtonTapped(sender: UIButton) {
    presentViewController(secondStoryboard, animated: true, completion: nil)
}

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

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

func didChangeColor(controller: SecondViewController, color: UIColor) {
    self.view.backgroundColor = color
}

}

和第二个VC：SecondViewController.swift

 protocol ColorChangeDelegate {
    func didChangeColor(controller: SecondViewController, color: UIColor)
}

class SecondViewController: UIViewController, UITextFieldDelegate {

    @IBOutlet weak var myRTextField: UITextField!
    @IBOutlet weak var myGTextField: UITextField!
    @IBOutlet weak var myBTextField: UITextField!

    var colorDelegate : ColorChangeDelegate?

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        myRTextField.delegate = self
        myGTextField.delegate = self
        myBTextField.delegate = self
    }

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

    func textFieldDidBeginEditing(textField: UITextField) {
        textField.becomeFirstResponder()
    }

    @IBAction func goButtonTapped(sender: UIButton) {
        let r = Int(myRTextField.text!)!
        let g = Int(myGTextField.text!)!
        let b = Int(myBTextField.text!)!
        let color = UIColor(red: CGFloat(r), green: CGFloat(g), blue: CGFloat(b), alpha: 1.0)
        self.view.endEditing(true)
        colorDelegate?.didChangeColor(self, color: color)
        presentingViewController?.dismissViewControllerAnimated(true, completion: nil)
    }
}

Answer 1

您要将代理人分配给secondVC，但实际呈现的视图控制器位于secondStoryboard，因此您应设置colorDelegate的{{1}}属性。< / p>

两个没有segue

1 个答案: