版本記錄

前言

iOS中有關(guān)視圖控件用戶能看到的都在UIKit框架里面，用戶交互也是通過(guò)UIKit進(jìn)行的。感興趣的參考上面幾篇文章。
1. UIKit框架（一） —— UIKit動(dòng)力學(xué)和移動(dòng)效果（一）
2. UIKit框架（二） —— UIKit動(dòng)力學(xué)和移動(dòng)效果（二）
3. UIKit框架（三） —— UICollectionViewCell的擴(kuò)張效果的實(shí)現(xiàn)（一）
4. UIKit框架（四） —— UICollectionViewCell的擴(kuò)張效果的實(shí)現(xiàn)（二）
5. UIKit框架（五） —— 自定義控件：可重復(fù)使用的滑塊（一）
6. UIKit框架（六） —— 自定義控件：可重復(fù)使用的滑塊（二）
7. UIKit框架（七） —— 動(dòng)態(tài)尺寸UITableViewCell的實(shí)現(xiàn)（一）
8. UIKit框架（八） —— 動(dòng)態(tài)尺寸UITableViewCell的實(shí)現(xiàn)（二）
9. UIKit框架（九） —— UICollectionView的數(shù)據(jù)異步預(yù)加載（一）
10. UIKit框架（十） —— UICollectionView的數(shù)據(jù)異步預(yù)加載（二）
11. UIKit框架（十一） —— UICollectionView的重用、選擇和重排序（一）
12. UIKit框架（十二） —— UICollectionView的重用、選擇和重排序（二）
13. UIKit框架（十三） —— 如何創(chuàng)建自己的側(cè)滑式面板導(dǎo)航（一）
14. UIKit框架（十四） —— 如何創(chuàng)建自己的側(cè)滑式面板導(dǎo)航（二）
15. UIKit框架（十五） —— 基于自定義UICollectionViewLayout布局的簡(jiǎn)單示例（一）
16. UIKit框架（十六） —— 基于自定義UICollectionViewLayout布局的簡(jiǎn)單示例（二）
17. UIKit框架（十七） —— 基于自定義UICollectionViewLayout布局的簡(jiǎn)單示例（三）
18. UIKit框架（十八） —— 基于CALayer屬性的一種3D邊欄動(dòng)畫的實(shí)現(xiàn)（一）
19. UIKit框架（十九） —— 基于CALayer屬性的一種3D邊欄動(dòng)畫的實(shí)現(xiàn)（二）
20. UIKit框架（二十） —— 基于UILabel跑馬燈類似效果的實(shí)現(xiàn)（一）
21. UIKit框架（二十一） —— UIStackView的使用（一）
22. UIKit框架（二十二） —— 基于UIPresentationController的自定義viewController的轉(zhuǎn)場(chǎng)和展示（一）
23. UIKit框架（二十三） —— 基于UIPresentationController的自定義viewController的轉(zhuǎn)場(chǎng)和展示（二）
24. UIKit框架（二十四） —— 基于UICollectionViews和Drag-Drop在兩個(gè)APP間的使用示例 （一）
25. UIKit框架（二十五） —— 基于UICollectionViews和Drag-Drop在兩個(gè)APP間的使用示例 （二）
26. UIKit框架（二十六） —— UICollectionView的自定義布局 （一）
27. UIKit框架（二十七） —— UICollectionView的自定義布局 （二）
28. UIKit框架（二十八） —— 一個(gè)UISplitViewController的簡(jiǎn)單實(shí)用示例 （一）
29. UIKit框架（二十九） —— 一個(gè)UISplitViewController的簡(jiǎn)單實(shí)用示例 （二）
30. UIKit框架（三十） —— 基于UICollectionViewCompositionalLayout API的UICollectionViews布局的簡(jiǎn)單示例（一）
31. UIKit框架（三十一） —— 基于UICollectionViewCompositionalLayout API的UICollectionViews布局的簡(jiǎn)單示例（二）
32. UIKit框架（三十二） —— 替換Peek and Pop交互的基于iOS13的Context Menus（一）
33. UIKit框架（三十三） —— 替換Peek and Pop交互的基于iOS13的Context Menus（二）
34. UIKit框架（三十四） —— Accessibility的使用（一）

源碼

1. Swift

首先看下工程組織結(jié)構(gòu)

下面看下sb中的內(nèi)容

接著就是源碼了

1. InstructionViewModel.swift

import Foundation

enum RecipeInstructionType {
  case ingredient, cookingInstructions
}

struct InstructionViewModel {
  let recipe: Recipe?
  var type: RecipeInstructionType
  var ingredientsState: [Bool] = []
  var directionsState: [Bool] = []
  
  init(recipe: Recipe, type: RecipeInstructionType) {
    self.recipe = recipe
    self.type = type
    
    if let ingredients = recipe.ingredients {
      ingredientsState = [Bool](repeating: false, count:ingredients.count)
    }
    
    if let directions = recipe.directions {
      directionsState = [Bool](repeating: false, count:directions.count)
    }
  }
  
  mutating func numberOfItems() -> Int {
    switch type {
    case .ingredient:
      if let ingredients = recipe?.ingredients {
        return ingredients.count
      }
    case .cookingInstructions:
      if let directions = recipe?.directions {
        return directions.count
      }
    }
    return 0
  }
  
  func numberOfSections() -> Int {
    return 1
  }
  
  func itemFor(_ index: Int) -> String? {
    switch type {
    case .ingredient:
      if let ingredients = recipe?.ingredients {
        return ingredients[index]
      }
    case .cookingInstructions:
      if let directions = recipe?.directions {
        return directions[index]
      }
    }
    return nil
  }
  
  func getStateFor(_ index: Int) -> Bool {
    switch type {
    case .ingredient:
      return ingredientsState[index]
    case .cookingInstructions:
      return directionsState[index]
    }
  }
  
  mutating func selectItemFor(_ index: Int) {
    switch type {
    case .ingredient:
      ingredientsState[index].toggle()
    case .cookingInstructions:
      directionsState[index].toggle()
    }
  }
}

2. Recipe.swift

import UIKit

// Data from: http://damndelicious.net/recipe-index/

enum RecipeDifficulty {
  case unknown
  case rating(Int)
}

extension RecipeDifficulty {
  init?(value: Int) {
    if value > 0 && value <= 5 {
      self = .rating(value)
    } else {
      self = .unknown
    }
  }
}

struct Recipe {
  let name: String
  let difficulty: RecipeDifficulty
  let photo: UIImage?
  let photoDescription: String
  let prepTime: Int
  let cookTime: Int
  let yield: Int
  let ingredients: [String]?
  let directions: [String]?
}

extension Recipe {
  init?(dict: [String: AnyObject]) {
    guard
      let name = dict["name"] as? String,
      let rawDifficulty = dict["difficulty"] as? Int,
      let difficulty = RecipeDifficulty(value: rawDifficulty),
      let prepTime = dict["prepTime"] as? Int,
      let cookTime = dict["cookTime"] as? Int,
      let yield = dict["yield"] as? Int,
      let ingredients = dict["ingredients"] as? [String],
      let directions = dict["directions"] as? [String],
      let photoDescription = dict["photoDescription"] as? String
      else {
        return nil
    }
    
    self.name = name
    self.difficulty = difficulty
    self.prepTime = prepTime
    self.cookTime = cookTime
    self.yield = yield
    self.ingredients = ingredients
    self.directions = directions
    self.photoDescription = photoDescription
    
    if let imageName = dict["imageName"] as? String, !imageName.isEmpty {
      photo = UIImage(named: imageName)
    } else {
      photo = nil
    }
  }
}

// MARK: - Load Sample Data

extension Recipe {
  static func loadDefaultRecipe() -> [Recipe]? {
    return self.loadRecipeFrom("RecipeList")
  }
  
  static func loadRecipeFrom(_ plistName: String) -> [Recipe]? {
    guard
      let path = Bundle.main.path(forResource: plistName, ofType: "plist"),
      let array = NSArray(contentsOfFile: path) as? [[String: AnyObject]]
      else {
        return nil
    }
    
    return array.compactMap { Recipe(dict: $0) }
  }
}

3. RecipeInstructionsViewController.swift

import UIKit

class RecipeInstructionsViewController: UITableViewController {
  private var headerView: UIView!
  private var instructionViewModel: InstructionViewModel!
  var recipe: Recipe!
  var didLikeFood = true
  @IBOutlet var likeButton: UIButton!
  @IBOutlet var backButton: UIButton!
  @IBOutlet var dishImageView: UIImageView!
  @IBOutlet var dishLabel: UILabel!
  
  override var prefersStatusBarHidden: Bool {
    return true
  }
  
  override func viewDidLoad() {
    super.viewDidLoad()
    
    assert(recipe != nil)
    
    backButton.accessibilityLabel = "back"
    backButton.accessibilityTraits = UIAccessibilityTraits.button
    
    isLikedFood(true)
    instructionViewModel = InstructionViewModel(recipe: recipe, type: .ingredient)
    setupRecipe()
    setupTableView()
  }
  
  // MARK: - Action Outlets
  
  @IBAction func likeButtonPressed(_ sender: AnyObject) {
    isLikedFood(!didLikeFood)
  }
  
  func isLikedFood(_ liked: Bool) {
    if liked {
      likeButton.setTitle("??", for: .normal)
      likeButton.accessibilityLabel = "Like"
      likeButton.accessibilityTraits = UIAccessibilityTraits.button
      didLikeFood = true
    } else {
      likeButton.setTitle("??", for: .normal)
      likeButton.accessibilityLabel = "Dislike"
      likeButton.accessibilityTraits = UIAccessibilityTraits.button
      didLikeFood = false
    }
  }
  
  @IBAction func toggleSegment(_ sender: UISegmentedControl) {
    if sender.selectedSegmentIndex == 0 { // Ingredients
      instructionViewModel.type = .ingredient
    } else { //Instruction
      instructionViewModel.type = .cookingInstructions
    }
    tableView.reloadData()
  }
  
  @IBAction func tapBackButton(_ sender: AnyObject) {
    navigationController?.popViewController(animated: true)
  }
  
  // MARK: - TableView Data Source
  
  override func numberOfSections(in tableView: UITableView) -> Int {
    return instructionViewModel.numberOfSections()
  }
  
  override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return instructionViewModel.numberOfItems()
  }
  
  override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: String(describing: InstructionCell.self), for: indexPath) as! InstructionCell
    
    if let description = instructionViewModel.itemFor(indexPath.item) {
      cell.configure(description)
    }
    
    let strike = instructionViewModel.getStateFor(indexPath.item)
    cell.shouldStrikeThroughText(strike)
    
    return cell
  }
  
  // MARK: - TableView Delegate
  
  override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    tableView.deselectRow(at: indexPath, animated: true)
    instructionViewModel.selectItemFor(indexPath.item)
    let cell = tableView.cellForRow(at: indexPath) as! InstructionCell
    let strike = instructionViewModel.getStateFor(indexPath.item)
    cell.shouldStrikeThroughText(strike)
  }
}

// MARK: - Setup

extension RecipeInstructionsViewController {
  func setupRecipe() {
    dishImageView.image = recipe.photo
    dishLabel.text = recipe.name
  }
  
  func setupTableView() {
    tableView.estimatedRowHeight = 79
    tableView.rowHeight = UITableView.automaticDimension
  }
}

4. RecipeListViewController.swift

import UIKit

class RecipeListViewController: UITableViewController {
  var recipes: [Recipe] = []
  var selectedRecipe: Recipe?
  
  override func viewDidLoad() {
    super.viewDidLoad()
    
    if let seedRecipe = Recipe.loadDefaultRecipe() {
      recipes += seedRecipe
      recipes = recipes.sorted(by: { $0.name < $1.name })
    }
    
    tableView.estimatedRowHeight = 100
    tableView.rowHeight = UITableView.automaticDimension
  }
  
  override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    navigationController?.setNavigationBarHidden(true, animated: true)
  }
  
  override func viewWillAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    navigationController?.setNavigationBarHidden(false, animated: true)
  }
  
  override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "showRecipe" {
      if let vc = segue.destination as? RecipeInstructionsViewController {
        vc.recipe = selectedRecipe
      }
    }
  }
  
  // MARK: - TableView Data Source
  
  override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return recipes.count
  }
  
  override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: String(describing: RecipeCell.self), for: indexPath) as! RecipeCell
    let recipe = recipes[indexPath.item]
    cell.configureCell(with: recipe)
    return cell
  }
  
  // MARK: - TableView Delegate
  
  override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    tableView.deselectRow(at: indexPath, animated: true)
    selectedRecipe = recipes[indexPath.item]
    performSegue(withIdentifier: "showRecipe", sender: self)
  }
}

5. InstructionCell.swift

import UIKit

class InstructionCell: UITableViewCell {
  @IBOutlet var checkmarkButton: UIButton!
  @IBOutlet var descriptionLabel: UILabel!
  
  func configure(_ description: String) {
    descriptionLabel.attributedText = nil
    descriptionLabel.text = description
  }
  
  @IBAction func checkmarkTapped(_ sender: AnyObject) {
    shouldStrikeThroughText(!checkmarkButton.isSelected)
  }
  
  func shouldStrikeThroughText(_ strikeThrough: Bool) {
    guard let text = descriptionLabel.text else {
      return
    }
    
    let attributeString =  NSMutableAttributedString(string: text)
    
    // 1
    checkmarkButton.isAccessibilityElement = false
    
    if strikeThrough {
      // 2
      descriptionLabel.accessibilityLabel = "Completed: \(text)"
      attributeString.addAttribute(NSAttributedString.Key.strikethroughStyle, value: 2, range: NSRange(text.startIndex..., in: text))
    } else {
      // 3
      descriptionLabel.accessibilityLabel = "Uncompleted: \(text)"
    }
    
    let buttonImage = strikeThrough ? UIImage(named: "icon-check") : UIImage(named: "icon-empty")
    checkmarkButton.setImage(buttonImage, for: .normal)
    descriptionLabel.attributedText = attributeString
  }
}

6. RecipeCell.swift

import UIKit

class RecipeCell: UITableViewCell {
  @IBOutlet var roundedBackgroundView: UIView!
  @IBOutlet var foodImageView: UIImageView!
  @IBOutlet var dishNameLabel: UILabel!
  @IBOutlet var difficultyLabel: UILabel!
  var difficultyValue: RecipeDifficulty = .unknown
  
  override func awakeFromNib() {
    super.awakeFromNib()
    styleAppearance()
  }
  
  func configureCell(with recipe:Recipe) {
    dishNameLabel.text = recipe.name
    foodImageView.image = recipe.photo
    difficultyValue = recipe.difficulty
    difficultyLabel.text = difficultyString
    applyAccessibility(recipe)
  }
  
  var difficultyString: String {
    switch difficultyValue {
    case .unknown:
      return ""
    case .rating(let value):
      var string = ""
      for _ in 0..<value {
        string.append("??")
      }
      return string
    }
  }
  
  func styleAppearance() {
    roundedBackgroundView.layer.cornerRadius = 3.0
    roundedBackgroundView.layer.masksToBounds = false
    roundedBackgroundView.layer.shadowOffset = CGSize(width: 0, height: 0)
    roundedBackgroundView.layer.shadowColor = #colorLiteral(red: 0.05439098924, green: 0.1344551742, blue: 0.1884709597, alpha: 1).cgColor
    roundedBackgroundView.layer.shadowRadius = 1.0
    roundedBackgroundView.layer.shadowOpacity = 0.3
    
    foodImageView.layer.cornerRadius = 3.0
  }
  
  override func setSelected(_ selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)
  }
}

// MARK: Accessibility

extension RecipeCell {
  func applyAccessibility(_ recipe: Recipe) {
    // 1
    foodImageView.accessibilityTraits = UIAccessibilityTraits.image
    // 2
    foodImageView.accessibilityLabel = recipe.photoDescription
    
    // 1
    difficultyLabel.isAccessibilityElement = true
    // 2
    difficultyLabel.accessibilityTraits = UIAccessibilityTraits.none
    // 3
    difficultyLabel.accessibilityLabel = "Difficulty Level"
    // 4
    switch recipe.difficulty {
    case .unknown:
      difficultyLabel.accessibilityValue = "Unknown"
    case .rating(let value):
      difficultyLabel.accessibilityValue = "\(value)"
    }
    
    difficultyLabel.font = UIFont.preferredFont(forTextStyle: .body)
    difficultyLabel.adjustsFontForContentSizeCategory = true
  }
}

后記

本篇主要講述了Accessibility的使用，感興趣的給個(gè)贊或者關(guān)注~~~