swift - 避免为很多按钮复制代码

Question

编辑我的问题:

Grimxn，我创建了一个子类并且可以看到它的工作原理，因为 borderWidth 和颜色。但是我仍然有几个关于如何添加我的功能的问题:

1. 我应该编码“func textField(textField: UITextField”还是“func textField(textField: MyCustomTextField”)？
2. 我应该如何处理“if textField == numberField01 {”？

3. 如何从 ViewController 代码“调用它”？

   class ViewController: UIViewController, UITextFieldDelegate {
   
   @IBOutlet weak var numberField01: UITextField!
   @IBOutlet weak var numberField02: MyCustomTextField!
   
   override func viewDidLoad() {
   super.viewDidLoad()
   numberField01.delegate = self
   numberField01.keyboardType = UIKeyboardType.NumberPad
   numberField02.delegate = self
   numberField02.keyboardType = UIKeyboardType.NumberPad
   

   class MyCustomTextField: UITextField {
   required init(coder aDecoder: NSCoder) {
       super.init(coder: aDecoder)
       self.layer.borderColor = UIColor.redColor().CGColor
       self.layer.borderWidth = 1.5
   
       func textField(textField: UITextField,
           shouldChangeCharactersInRange range: NSRange,
           replacementString string: String)
           -> Bool {
               var result = true
               var prospectiveText = (textField.text as NSString).stringByReplacingCharactersInRange(range, withString: string)
               prospectiveText = prospectiveText.stringByReplacingOccurrencesOfString(".", withString: "", options: NSStringCompareOptions.LiteralSearch, range: nil)
               if textField == numberField01 {
                   if count(string)>0 {
                       let disallowedCharacterSet = NSCharacterSet(charactersInString: "0123456789").invertedSet
                       let replacementStringIsLegal = string.rangeOfCharacterFromSet(disallowedCharacterSet) == nil
                       let resultingStringLengthIsLegal = count(prospectiveText) <= 4
                       let scanner = NSScanner(string: prospectiveText)
                       let resultingTextIsNumeric = scanner.scanDecimal(nil) && scanner.atEnd
                       result = replacementStringIsLegal && resultingStringLengthIsLegal && resultingTextIsNumeric
                   }
               }
               return result
       }
   }
   
   }
   

   原问题:以下代码适用于一个文本字段 (numberField01)。它确保输入仅为十进制，放置小数点，并防止用户粘贴非十进制字符串。但是我有更多的按钮...(numberField02 及以上)。我如何才能处理更多按钮，而不仅仅是为每个按钮复制我的代码？

   class ViewController: UIViewController, UITextFieldDelegate {
   
   @IBOutlet weak var numberField01: UITextField!
   @IBOutlet weak var numberField02: UITextField!
   
   override func viewDidLoad() {
   super.viewDidLoad()
   numberField01.delegate = self
   numberField01.keyboardType = UIKeyboardType.NumberPad
   numberField02.delegate = self
   numberField02.keyboardType = UIKeyboardType.NumberPad
   }
   
   override func didReceiveMemoryWarning() {
   super.didReceiveMemoryWarning()
   }
   
   // Tap background to add decimal point and defocus keyboard
   
   @IBAction func userTappedBackground(sender: AnyObject) {
   for view in self.view.subviews as! [UIView] {
     if let textField = view as? UITextField {
       if count(numberField01.text) > 0 {
           var numberString = numberField01.text
           numberString = numberString.stringByReplacingOccurrencesOfString(".", withString: "", options: NSStringCompareOptions.LiteralSearch, range: nil)
           var numberFromString = Double(numberString.toInt()!) / 100
           numberField01.text = String(format:"%.2f", numberFromString)
       }
       textField.resignFirstResponder()
     }
   }
   }
   
   func textField(textField: UITextField,
       shouldChangeCharactersInRange range: NSRange,
       replacementString string: String)
       -> Bool {
           var result = true
           var prospectiveText = (textField.text as NSString).stringByReplacingCharactersInRange(range, withString: string)
           prospectiveText = prospectiveText.stringByReplacingOccurrencesOfString(".", withString: "", options: NSStringCompareOptions.LiteralSearch, range: nil)
           if textField == numberField01 {
               if count(string)>0 {
                   let disallowedCharacterSet = NSCharacterSet(charactersInString: "0123456789").invertedSet
                   let replacementStringIsLegal = string.rangeOfCharacterFromSet(disallowedCharacterSet) == nil
                    let resultingStringLengthIsLegal = count(prospectiveText) <= 4
                   let scanner = NSScanner(string: prospectiveText)
                   let resultingTextIsNumeric = scanner.scanDecimal(nil) && scanner.atEnd
                   result = replacementStringIsLegal && resultingStringLengthIsLegal && resultingTextIsNumeric
               }
           }
           return result
   }
   }
   

Answer 1

所以类似于下面的内容:

    Button GetButtonCommonFeatures(Button myButton)
    {
        Write common code here....
        e.g. myButton.delegate = self;...
        return myButton;
    }

然后为每个按钮调用您的方法。让我们以 numberField01 为例。您将在适用于每个按钮的方法中包含代码。

    numberField01 = GetButtonCommonFeatures(numberField01);

希望对你有帮助