如何在 swift 中读取数组和字典的 plist

Question

我正在关注 Apple 示例项目 TVAnimationsGestures，但将其应用于我自己的项目之一。我需要将数据从 plist 加载到我的类中，但我似乎无法弄清楚如何快速做到这一点。这是 plist 尝试读取的图像。

示例项目使用此方法读取plist

- (NSArray *)plays {

if (_plays == nil) {

    NSURL *url = [[NSBundle mainBundle] URLForResource:@"PlaysAndQuotations" withExtension:@"plist"];
    NSArray *playDictionariesArray = [[NSArray alloc ] initWithContentsOfURL:url];
    _plays = [NSMutableArray arrayWithCapacity:[playDictionariesArray count]];

    for (NSDictionary *playDictionary in playDictionariesArray) {

        APLPlay *play = [[APLPlay alloc] init];
        play.name = playDictionary[@"playName"];

        NSArray *quotationDictionaries = playDictionary[@"quotations"];
        NSMutableArray *quotations = [NSMutableArray arrayWithCapacity:[quotationDictionaries count]];

        for (NSDictionary *quotationDictionary in quotationDictionaries) {

            APLQuotation *quotation = [[APLQuotation alloc] init];
            [quotation setValuesForKeysWithDictionary:quotationDictionary];

            [quotations addObject:quotation];
        }
        play.quotations = quotations;

        [_plays addObject:play];
    }
}

return _plays;

}

我环顾四周并设法让大部分内容不显示任何错误，但我认为它没有正确完成，因为有很多演员表。这是我已经走了多远：

    func loadFoodCategoryData() ->[Any] {
    // foodCategoryData is declared outside the function
    if foodCategoryData == nil {

        var url = NSBundle.mainBundle().URLForResource("Items", withExtension: "plist")!
        var categoryDictionaryArray = NSArray(contentsOfURL: url) as! [[String:AnyObject!]]
        foodCategoryData = Array()

        for foodDictionary:Dictionary in categoryDictionaryArray {

            var foodCat = FoodCategories()
            foodCat.foodCategoryName = foodDictionary["categoryName"] as! String

            var foodItemsDict = foodDictionary["items"]
            var foodItemsArray = [AnyObject]()

            for foodItems in foodDictionary {

                var foodItem:FoodItems = FoodItems()
                foodItem.setValuesForKeysWithDictionary(foodItems as! Dictionary)

                foodItemsArray.append(foodItem)

            }
        }
    }

    return foodCategoryData
}

谁有更好更有效的方法来将此 plist 加载到我的类中？

Answer 1

惰性初始化变量在 Swift 中具有特定的语法。相当于ObjC的代码是（体简化）

  lazy var plays : [AnyObject] = {
    var foodCategoryData = [AnyObject]()
    // do things
    foodCategoryData.append("something")
    return foodCategoryData
  }()

从 AnyObject 向下转换是一种痛苦但必要的

编辑

您的代码非常接近。试试这个（未经测试）

lazy var foodCategoryData : [AnyObject] = {

  let url = NSBundle.mainBundle().URLForResource("Items", withExtension: "plist")!
  var categoryDictionaryArray = NSArray(contentsOfURL: url) as! [[String:AnyObject!]]
  var foodItemsArray = [FoodItems]()

  for foodDictionary in categoryDictionaryArray {

    var foodCat = FoodCategories()
    foodCat.foodCategoryName = foodDictionary["categoryName"] as! String

    var foodItemsDict = foodDictionary["items"] as! [String:AnyObject]


    for foodItems in foodDictionary {

      var foodItem:FoodItems = FoodItems()
      foodItem.setValuesForKeysWithDictionary(foodItems as! Dictionary)

      foodItemsArray.append(foodItem)

    }
  }
  return foodItemsArray
 }()