iOS swift : saving an array of custom classes

Question

我是编程新手。我正在快速为 iOS 制作一个小数据库程序。

我有一个人类:

class Person : NSObject {
    var firstName : String
    var lastName : String

    init (firstName : String, lastName : String) {
        self.firstName = firstName
        self.lastName = lastName
    }
}

我在 View Controller 的顶部声明了一个类数组:

    var peopleArray = [Person]()

然后我通过声明一些示例用户来填充数组并将其附加到数组:

    var nateB = Person(firstName: "Nate", lastName: "Birkholz")
    var nateC = Person(firstName: "Nate", lastName: "Carson")
    var nateD = Person(firstName: "Nate", lastName: "Donnelly")
    self.peopleArray.append(nateB)
    self.peopleArray.append(nateC)
    self.peopleArray.append(nateD)

然后我尝试将数据保存到 plist 文件中:

        let fileManager = (NSFileManager.defaultManager())
        let directorys : [String]? = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory,NSSearchPathDomainMask.AllDomainsMask, true) as? [String]

        if (directorys != nil){
            let directories:[String] = directorys!;
            let pathToFile = directories[0]; //documents directory
            let plistfile = "PeopleArray.plist"
            let plistpath = pathToFile.stringByAppendingPathComponent(plistfile);

            if !fileManager.fileExistsAtPath(plistpath){ 

                println("Declaring cocoaArray")
                var cocoaArray : NSArray = peopleArray
                cocoaArray.writeToFile(plistpath, atomically: true)
            println("I wrote an array to the file at\n\n\(plistpath)")
            }

plist 文件没有被创建，它默默地创建失败并且函数完成就像它已经完成一样。有什么想法吗？

swift 数据类型和数据结构与 cocoa 类的模糊兼容性过程让我感到沮丧。我只想保存一个危险的文件。如果我将我的数组声明为 NSArray，我也不能使用“追加”函数，我也不能 += 一个项目到数组中......

更新:

我在我的 Person 类中添加了以下函数:

func encodeWithCoder(aCoder: NSCoder!) {
    aCoder.encodeObject(firstName, forKey:"firstName")
    aCoder.encodeObject(lastName, forKey:"lastName")
}

init (coder aDecoder: NSCoder!) {
    self.firstName = aDecoder.decodeObjectForKey("firstName") as String
    self.lastName = aDecoder.decodeObjectForKey("lasName") as String
}

现在保存文件是:

let fileManager = (NSFileManager.defaultManager())
        let directorys : [String]? = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory,NSSearchPathDomainMask.AllDomainsMask, true) as? [String]

        println("value of directorys is \(directorys)")

        if (directorys != nil){
            let directories:[String] = directorys!;
            let pathToFile = directories[0]; //documents directory

            let plistfile = "PeopleArray.plist"
            let plistpath = pathToFile.stringByAppendingPathComponent(plistfile);

            if !fileManager.fileExistsAtPath(plistpath){  //writing Plist file

                self.createInitialPeople()

                println("Declaring cocoaArray")
                var cocoaArray : NSArray = [NSKeyedArchiver.archivedDataWithRootObject(peopleArray)]
                println("writing to path")
                cocoaArray.writeToFile(plistpath, atomically: true)
                let tellMe = cocoaArray.writeToFile(plistpath, atomically: true)
                println("Return of write is \(tellMe)")
            } 

创建了一个包含难以理解的数据的 Plist 文件。

我关闭应用程序并重新启动它，然后我也尝试加载文件:

         else {            //Reading Plist file
            println("\n\nPlist file found at \(plistpath)")

            let cocoaArray = NSMutableArray.arrayWithContentsOfFile(plistpath)

            peopleArray = cocoaArray as Array
        }
    }

我失败了，因为我无法向下转换“AnyObject 与‘Person’不相同。我尝试过以多种方式向下转换它，但无法成功。这真的很令人沮丧。

Answer 1

将以下函数添加到 Person 类后:

func encodeWithCoder(aCoder: NSCoder!) {
    aCoder.encodeObject(firstName, forKey:"firstName")
    aCoder.encodeObject(lastName, forKey:"lastName")
}


init (coder aDecoder: NSCoder!) {
    self.firstName = aDecoder.decodeObjectForKey("firstName") as String
    self.lastName = aDecoder.decodeObjectForKey("lasName") as String
}

您应该使用【NSKeyedArchiver】和【NSKeyedUnarchiver】来存储和获取数组。

谢谢@Anthony Kong。

他的回答很有帮助，但我认为下面的代码确实可以解决问题。

在 PLIST 中存储数组

let paths = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory,NSSearchPathDomainMask.AllDomainsMask, true)
let path: AnyObject = paths[0]
let arrPath = path.stringByAppendingString("/array.plist")
NSKeyedArchiver.archiveRootObject(peopleArray, toFile: arrPath)

获取数组形式的 PLIST

if let tempArr: [Person] = NSKeyedUnarchiver.unarchiveObjectWithFile(arrPath) as? [Person] {
    peopleArray = tempArr
}