如何在核心数据中存储数组 (Swift)

Question

我的代码读取一个文本文件并将文件的内容存储在一个数组中。我在下一步时遇到了麻烦；将数组的内容传输到 Core Data 中。 .txt 文件只是一个简短的水果列表。实体是 "Fruit"，属性是 "fruitname"。

打印时只显示最后一个数组元素。这是我的代码：-

    import UIKit
    import CoreData

    class ViewController: UIViewController {

    override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.


    // STORE .TXT FILE IN ARRAY.....
    let bundle = NSBundle.mainBundle()
    let fruitList = bundle.pathForResource("List of Fruits", ofType: "txt")

    let fruitArray = String(contentsOfFile: fruitList!, encoding: NSUTF8StringEncoding, error: nil)!.componentsSeparatedByString("\r")


    for x in fruitArray {
        println(x)

    }

    // STORE FRUIT-ARRAY IN CORE DATA......
    var appDel = UIApplication.sharedApplication().delegate as AppDelegate

    var context : NSManagedObjectContext! = appDel.managedObjectContext!

    var newFruit = NSEntityDescription.insertNewObjectForEntityForName("Fruit", inManagedObjectContext: context) as NSManagedObject

    for fruit in fruitArray {

        newFruit.setValue(fruit, forKey: "fruitname")
    }

    context.save(nil)


    // RETRIEVE AND PRINT STORED VALUES....
    var request = NSFetchRequest(entityName: "Fruit")
    request.returnsObjectsAsFaults = false

    var results = context.executeFetchRequest(request, error: nil)

    println(results)

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

}

这是两个 println 语句的输出....

// fruitArray 的 Println 苹果杏香蕉覆盆子黑莓蓝莓椰子蔓越莓日期火龙果图葡萄番石榴甘露猕猴桃柠檬酸橙荔枝芒果瓜橙子番木瓜菠萝覆盆子杨桃草莓西瓜

//核心数据打印

可选（........ 水果名称=西瓜； })]

有人可以帮助确保 fruitArray 中的所有内容都保存在核心数据中吗？提前致谢。

Answer 1

您只创建了一个 newFruit。因此，您的 for fruit in fruitArray 循环只是重复重新分配 fruitname 属性.

将您的代码更改为：

for fruit in fruitArray {
  var newFruit = NSEntityDescription.insertNewObjectForEntityForName ("Fruit", 
     inManagedObjectContext: context) as NSManagedObject

  newFruit.setValue(fruit, forKey: "fruitname")
}

如何在核心数据中存储数组 (Swift)

How do you store an array in core data (Swift)

core-data

ios

swift