在不同 class 中创建 UITextField 不允许输入

Question

我在单独的class:

中有这个功能

public static func TextField(x:CGFloat=0, y:CGFloat=0, width: CGFloat=0, height: CGFloat=0, placeholder: String="", fontSize:CGFloat=15, fontColor: UIColor=UIColor.black, fontWeight:UIFont.Weight=UIFont.Weight.light ,passwordField: Bool = false) -> UITextField{
        weak var delegate: UITextFieldDelegate?

        let textfield =  UITextField(frame: CGRect(x: x, y: y, width: width, height: height))
        textfield.placeholder = placeholder
        textfield.textColor = fontColor
        textfield.font = UIFont.systemFont(ofSize: fontSize, weight: fontWeight)
        textfield.isSecureTextEntry = passwordField
        textfield.isUserInteractionEnabled = true
        textfield.autocorrectionType = UITextAutocorrectionType.no
        textfield.keyboardType = UIKeyboardType.default
        textfield.contentVerticalAlignment = UIControlContentVerticalAlignment.center
        textfield.delegate = delegate
        return textfield
    }

并且它正确地创建了 UITextField，具有我预期的正确行为，我无法输入任何 UITextFields。

此外，我尝试像这样添加一个单独的 class：

class MyTextFieldDelegate : NSObject, UITextFieldDelegate{
  func textFieldShouldReturn(textField: UITextField!) -> Bool{
    textField.resignFirstResponder()
    return true;
  }
}

但是没有用。另外，阅读

unowned(unsafe) var delegate: UITextFieldDelegate?

returns错误：

'unowned' may only be applied to class and class-bound protocol types, not 'UITextFieldDelegate?'

我怎么不能在 UITextfield 上写字？

Answer 1

您需要创建一个带有强引用的静态 let 变量，以便在您的工厂函数中使用它（遵循 Swift 命名约定并调用它，例如 makeDefaultTextField），只是为了在您分配时更清楚您赋予的委托负责管理委托方法给您的 class:

static let myDelegate = MyTextFieldDelegate()

public static func makeDefaultTextField(x:CGFloat=0, y:CGFloat=0, width: CGFloat=0, height: CGFloat=0, placeholder: String="", fontSize:CGFloat=15, fontColor: UIColor=UIColor.black, fontWeight:UIFont.Weight=UIFont.Weight.light ,passwordField: Bool = false) -> UITextField {
    let textfield =  UITextField(frame: CGRect(x: x, y: y, width: width, height: height))
    //....
    textField.delegate = myDelegate
}

如果您想在 ViewController 中管理委托方法（强烈建议），您可以通过这种方式进行，例如：

class YourViewController: UIViewController {

   override func viewDidLoad() {
        super.viewDidLoad()
        let txtField = YourClass.makeDefaultTextField()
        txtField.delegate = self
    }
}

extension YourViewController: UITextFieldDelegate {
    //call here the methods 
}

在不同 class 中创建 UITextField 不允许输入

Create UITextField in different class doesn't allow to type

uitextfield

swift

swift4