只对方法使用任何架构模式都不是一个好的实践，所以假设你有一个包含许多类或文件的完整应用程序。
重要的一点是，使用任何特定的模式并不是固定的/强制的。它实际上取决于代码，有时候你会为了处理一个方法而写很多代码。所以试着想一个最佳的方法来使代码更具可测试性和可伸缩性。
但是为了便于参考，您可以检查以下代码：
在视图控制器上：

lazy var presenter:Presenter = Presenter(view:self)

 @IBAction func onEmailValueChanged(_ sender: UITextField) {
    presenter.validateHasMinimumLength(password: sender.text!)
    presenter.validateHasCapitalLetter(password: sender.text!)
    presenter.validateHasNumber(password: sender.text!)
    presenter.validateHasSpecialCharacter(password: sender.text!)
}

//采用视图控制器：视图控制器上的PrensenterView协议

extension ViewController:PrensenterViewProtocol {

func updateLengthCheckmarkImageView(isHidden:Bool) {
    passLengthCheckmarkImageView.isHidden = isHidden
}

func updateUpperCaseCheckmarkImageView(isHidden:Bool) {
    passHasUppercaseCheckmarkImageView.isHidden = isHidden
}

func updateNumberCheckmarkImageView(isHidden:Bool) {
    passHasNumberCheckmarkImageView.isHidden = isHidden
}

func updateSymbolCheckmarkImageView(isHidden:Bool) {
    passHasSymbolCheckmarkImageView.isHidden = isHidden
}

func updateResetButton(isHidden:Bool) {
    resetButton.isHidden = isHidden
}

}

演示者查看协议为：

protocol PrensenterViewProtocol:NSObjectProtocol {
    func updateLengthCheckmarkImageView(isHidden:Bool)
    func updateUpperCaseCheckmarkImageView(isHidden:Bool)
    func updateNumberCheckmarkImageView(isHidden:Bool)
    func updateSymbolCheckmarkImageView(isHidden:Bool)
    func updateResetButton(isHidden:Bool)
}

主讲人：

class Presenter {
weak var view:PrensenterViewProtocol!
private var hasMinimumLength:Bool = false
private var hasCapitalLetter:Bool = false
private var hasNumber:Bool = false
private var hasSpecialCharacter:Bool = false

init(view:PrensenterViewProtocol) {
    self.view = view
}
    
func validateHasMinimumLength(password:String?) {
    hasMinimumLength = TextValidationHelper.validateHasMinimumLength(password: password)
    self.view.updateLengthCheckmarkImageView(isHidden: hasMinimumLength)
    checkAllValidations()
}

func validateHasCapitalLetter(password:String?) {
    hasCapitalLetter = TextValidationHelper.validateHasCapitalLetter(password: password)
    self.view.updateUpperCaseCheckmarkImageView(isHidden:hasCapitalLetter )
    checkAllValidations()
}

func validateHasNumber(password:String?) {
    hasNumber = TextValidationHelper.validateHasNumber(password: password)
    self.view.updateNumberCheckmarkImageView(isHidden: hasNumber)
    checkAllValidations()
}

func validateHasSpecialCharacter(password:String?) {
    hasSpecialCharacter = TextValidationHelper.validateHasSpecialCharacter(password: password)
    self.view.updateSymbolCheckmarkImageView(isHidden: hasSpecialCharacter)
    checkAllValidations()
}

func checkAllValidations() {
    let areAllValid:Bool = hasMinimumLength && hasCapitalLetter && hasNumber && hasSpecialCharacter ? false : true
    self.view.updateResetButton(isHidden: areAllValid)
}

}