iOS登录流程中如何复用相似但略有差异的视图？

方案1：自定义通用输入视图，通过配置参数传递差异值 #

创建封装了输入框、标题标签等通用元素的自定义UIView，通过暴露配置属性适配邮箱/密码两种场景，把差异项转化为可配置参数。

示例代码：

import UIKit

class AuthInputView: UIView {
    // 通用控件
    private let titleLabel = UILabel()
    private let inputTextField = UITextField()
    
    // 配置属性，设置时自动更新UI
    var titleText: String? {
        didSet {
            titleLabel.text = titleText
        }
    }
    
    var inputPlaceholder: String? {
        didSet {
            inputTextField.placeholder = inputPlaceholder
        }
    }
    
    var keyboardType: UIKeyboardType = .default {
        didSet {
            inputTextField.keyboardType = keyboardType
        }
    }
    
    var isSecureInput: Bool = false {
        didSet {
            inputTextField.isSecureTextEntry = isSecureInput
        }
    }
    
    // 初始化方法
    override init(frame: CGRect) {
        super.init(frame: frame)
        setupUI()
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        setupUI()
    }
    
    // 构建通用UI布局
    private func setupUI() {
        // 添加子控件并设置AutoLayout约束（示例简化，实际需根据布局需求实现）
        titleLabel.translatesAutoresizingMaskIntoConstraints = false
        inputTextField.translatesAutoresizingMaskIntoConstraints = false
        
        addSubview(titleLabel)
        addSubview(inputTextField)
        
        NSLayoutConstraint.activate([
            titleLabel.topAnchor.constraint(equalTo: topAnchor),
            titleLabel.leadingAnchor.constraint(equalTo: leadingAnchor),
            inputTextField.topAnchor.constraint(equalTo: titleLabel.bottomAnchor, constant: 8),
            inputTextField.leadingAnchor.constraint(equalTo: leadingAnchor),
            inputTextField.trailingAnchor.constraint(equalTo: trailingAnchor),
            inputTextField.heightAnchor.constraint(equalToConstant: 44)
        ])
        
        titleLabel.font = .systemFont(ofSize: 16, weight: .medium)
        inputTextField.borderStyle = .roundedRect
    }
}

在ViewController中使用时传入不同配置：

// 邮箱页面
class EmailViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        let emailInputView = AuthInputView(frame: CGRect(x: 20, y: 100, width: view.bounds.width - 40, height: 80))
        emailInputView.titleText = "Enter email"
        emailInputView.inputPlaceholder = "your@email.com"
        emailInputView.keyboardType = .emailAddress
        view.addSubview(emailInputView)
    }
}

// 密码页面
class PasswordViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        let passwordInputView = AuthInputView(frame: CGRect(x: 20, y: 100, width: view.bounds.width - 40, height: 80))
        passwordInputView.titleText = "Enter password"
        passwordInputView.inputPlaceholder = "your password"
        passwordInputView.keyboardType = .asciiCapable
        passwordInputView.isSecureInput = true
        view.addSubview(passwordInputView)
    }
}

方案2：用同一个ViewController，通过类型枚举区分场景 #

如果两个页面逻辑高度重合，可只用一个通用ViewController，通过枚举标记当前场景，内部根据枚举值配置UI差异。

示例代码：

import UIKit

enum AuthScene {
    case email
    case password
}

class AuthViewController: UIViewController {
    private let titleLabel = UILabel()
    private let inputTextField = UITextField()
    private let currentScene: AuthScene
    
    // 初始化时传入场景类型
    init(scene: AuthScene) {
        self.currentScene = scene
        super.init(nibName: nil, bundle: nil)
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        setupCommonUI()
        configureForScene()
    }
    
    private func setupCommonUI() {
        // 通用布局配置
        titleLabel.translatesAutoresizingMaskIntoConstraints = false
        inputTextField.translatesAutoresizingMaskIntoConstraints = false
        
        view.addSubview(titleLabel)
        view.addSubview(inputTextField)
        
        NSLayoutConstraint.activate([
            titleLabel.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 100),
            titleLabel.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20),
            inputTextField.topAnchor.constraint(equalTo: titleLabel.bottomAnchor, constant: 8),
            inputTextField.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20),
            inputTextField.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -20),
            inputTextField.heightAnchor.constraint(equalToConstant: 44)
        ])
        
        titleLabel.font = .systemFont(ofSize: 16, weight: .medium)
        inputTextField.borderStyle = .roundedRect
    }
    
    // 根据场景配置差异项
    private func configureForScene() {
        switch currentScene {
        case .email:
            titleLabel.text = "Enter email"
            inputTextField.placeholder = "your@email.com"
            inputTextField.keyboardType = .emailAddress
        case .password:
            titleLabel.text = "Enter password"
            inputTextField.placeholder = "your password"
            inputTextField.keyboardType = .asciiCapable
            inputTextField.isSecureTextEntry = true
        }
    }
    
    // 通用提交逻辑
    @objc private func submitTapped() {
        guard let inputText = inputTextField.text, !inputText.isEmpty else { return }
        if currentScene == .email {
            // 邮箱验证通过后跳转密码页面
            let passwordVC = AuthViewController(scene: .password)
            present(passwordVC, animated: true)
        } else {
            // 密码验证逻辑
        }
    }
}

使用时直接创建对应场景的实例：

// 启动登录流程
let emailVC = AuthViewController(scene: .email)
present(emailVC, animated: true)

方案3：基于基类ViewController的继承复用 #

如果需要保留两个独立的ViewController但减少重复代码，可先写基类封装通用逻辑，子类仅实现差异部分。

示例代码：

import UIKit

class BaseAuthViewController: UIViewController {
    // 通用控件
    let titleLabel = UILabel()
    let inputTextField = UITextField()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        setupCommonUI()
        configureUI() // 子类重写此方法配置差异
    }
    
    // 通用UI布局和逻辑
    private func setupCommonUI() {
        titleLabel.translatesAutoresizingMaskIntoConstraints = false
        inputTextField.translatesAutoresizingMaskIntoConstraints = false
        
        view.addSubview(titleLabel)
        view.addSubview(inputTextField)
        
        NSLayoutConstraint.activate([
            titleLabel.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 100),
            titleLabel.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20),
            inputTextField.topAnchor.constraint(equalTo: titleLabel.bottomAnchor, constant: 8),
            inputTextField.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20),
            inputTextField.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -20),
            inputTextField.heightAnchor.constraint(equalToConstant: 44)
        ])
        
        titleLabel.font = .systemFont(ofSize: 16, weight: .medium)
        inputTextField.borderStyle = .roundedRect
    }
    
    // 子类必须重写，配置差异项
    func configureUI() {}
}

// 邮箱子类
class EmailViewController: BaseAuthViewController {
    override func configureUI() {
        titleLabel.text = "Enter email"
        inputTextField.placeholder = "your@email.com"
        inputTextField.keyboardType = .emailAddress
    }
    
    // 邮箱专属逻辑可在此补充
}

// 密码子类
class PasswordViewController: BaseAuthViewController {
    override func configureUI() {
        titleLabel.text = "Enter password"
        inputTextField.placeholder = "your password"
        inputTextField.keyboardType = .asciiCapable
        inputTextField.isSecureTextEntry = true
    }
    
    // 密码专属逻辑可在此补充
}

三个方案可按需选择：仅视图重复选方案1；页面逻辑高度一致选方案2；需保留独立ViewController选方案3。

内容的提问来源于stack exchange，提问作者Nala