iOS使用UIKeyInput自定义密码输入框的方法示例

extension CLPasswordInputView: UIKeyInput {
 var hasText: Bool {
  return text.length > 0
 }
 
 func insertText(_ text: String) {
  if self.text.length < config.passwordNum {
   let cs = NSCharacterSet.init(charactersIn: "0123456789").inverted
   let string = text.components(separatedBy: cs).joined(separator: "")
   let basicTest = text == string
   if basicTest {
    self.text.append(text)
    delegate?.passwordInputViewDidChange(passwordInputView: self)
    if self.text.length == config.passwordNum {
     delegate?.passwordInputViewCompleteInput(passwordInputView: self)
    }
    setNeedsDisplay()
   }
  }
 }
 
 func deleteBackward() {
  if text.length > 0 {
   text.deleteCharacters(in: NSRange(location: text.length - 1, length: 1))
   delegate?.passwordInputViewDidChange(passwordInputView: self)
  }
  delegate?.passwordInputViewDidDeleteBackward(passwordInputView: self)
  setNeedsDisplay()
 }
}

extension CLPasswordInputView {
 override func becomeFirstResponder() -> Bool {
  if !isShow {
   delegate?.passwordInputViewBeginInput(passwordInputView: self)
  }
  isShow = true;
  return super.becomeFirstResponder()
 }
 override func resignFirstResponder() -> Bool {
  if isShow {
   delegate?.passwordInputViewEndInput(passwordInputView: self)
  }
  isShow = false
  return super.resignFirstResponder()
 }
 var keyboardType: UIKeyboardType {
  get {
   return .numberPad
  }
  set {
   
  }
 }
 override var canBecomeFirstResponder: Bool {
  return true
 }
 override var canResignFirstResponder: Bool {
  return true
 }
 override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
  super.touchesBegan(touches, with: event)
  if !isFirstResponder {
   _ = becomeFirstResponder()
  }
 }
 func updateWithConfig(config: ((CLPasswordInputViewConfigure) -> Void)?) -> Void {
  config?(self.config)
  backgroundColor = self.config.backgroundColor
  setNeedsDisplay()
 }
 override func layoutSubviews() {
  super.layoutSubviews()
  setNeedsDisplay()
 }
 override func draw(_ rect: CGRect) {
  let height = rect.size.height
  let width = rect.size.width
  let squareWidth = min(max(min(height, config.squareWidth), config.pointRadius * 4), height)
  let pointRadius = min(config.pointRadius, squareWidth * 0.5) * 0.8
  let middleSpace = CGFloat(width - CGFloat(config.passwordNum) * squareWidth) / CGFloat(CGFloat(config.passwordNum - 1) + config.spaceMultiple * 2)
  let leftSpace = middleSpace * config.spaceMultiple
  let y = (height - squareWidth) * 0.5
  
  let context = UIGraphicsGetCurrentContext()
  
  for i in 0 ..< config.passwordNum {
   context?.addRect(CGRect(x: leftSpace + CGFloat(i) * squareWidth + CGFloat(i) * middleSpace, y: y, width: squareWidth, height: squareWidth))
   context?.setLineWidth(1)
   context?.setStrokeColor(config.rectColor.cgColor)
   context?.setFillColor(config.rectBackgroundColor.cgColor)
  }
  context?.drawPath(using: .fillStroke)
  context?.setFillColor(config.pointColor.cgColor)
  
  for i in 0 ..< text.length {
   context?.addArc(center: CGPoint(x: leftSpace + CGFloat(i + 1) * squareWidth + CGFloat(i) * middleSpace - squareWidth * 0.5, y: y + squareWidth * 0.5), radius: pointRadius, startAngle: 0, endAngle: .pi * 2, clockwise: true)
   context?.drawPath(using: .fill)
  }
 }
}

class CLPasswordInputViewConfigure: NSObject {
 ///密码的位数
 var passwordNum: UInt = 6
 ///边框正方形的大小
 var squareWidth: CGFloat = 50
 ///黑点的半径
 var pointRadius: CGFloat = 18 * 0.5
 ///边距相对中间间隙倍数
 var spaceMultiple: CGFloat = 5;
 ///黑点颜色
 var pointColor: UIColor = UIColor.black
 ///边框颜色
 var rectColor: UIColor = UIColor.lightGray
 ///输入框背景颜色
 var rectBackgroundColor: UIColor = UIColor.white
 ///控件背景颜色
 var backgroundColor: UIColor = UIColor.white
 
 class func defaultConfig() -> CLPasswordInputViewConfigure {
  let configure = CLPasswordInputViewConfigure()
  return configure
 }
}

func updateWithConfig(config: ((CLPasswordInputViewConfigure) -> Void)?) -> Void {
  config?(self.config)
  backgroundColor = self.config.backgroundColor
  setNeedsDisplay()
 }

protocol CLPasswordInputViewDelegate {
 ///输入改变
 func passwordInputViewDidChange(passwordInputView:CLPasswordInputView) -> Void
 ///点击删除
 func passwordInputViewDidDeleteBackward(passwordInputView:CLPasswordInputView) -> Void
 ///输入完成
 func passwordInputViewCompleteInput(passwordInputView:CLPasswordInputView) -> Void
 ///开始输入
 func passwordInputViewBeginInput(passwordInputView:CLPasswordInputView) -> Void
 ///结束输入
 func passwordInputViewEndInput(passwordInputView:CLPasswordInputView) -> Void
}

extension CLPasswordInputViewDelegate {
 ///输入改变
 func passwordInputViewDidChange(passwordInputView:CLPasswordInputView) -> Void {
  
 }
 ///点击删除
 func passwordInputViewDidDeleteBackward(passwordInputView:CLPasswordInputView) -> Void {
  
 }
 ///输入完成
 func passwordInputViewCompleteInput(passwordInputView:CLPasswordInputView) -> Void {
  
 }
 ///开始输入
 func passwordInputViewBeginInput(passwordInputView:CLPasswordInputView) -> Void {
  
 }
 ///结束输入
 func passwordInputViewEndInput(passwordInputView:CLPasswordInputView) -> Void {
  
 }
}