Swift

下面通过一个例子将联系人数据保存到沙盒的“documents”目录中。（联系人是一个数组集合，内部为自定义对象）。

功能如下：

1，点击“保存”将联系人存入userList.plist文件中

2，点击“读取”从数据文件中加载解析出联系人

注意：

1，本例使用了NSCoder，这个封装了许多技术细节，使用它我们可以很轻易的将对象写到文件中，也可以用它将文件中的对象转换回来。

2，自定义对象必须添加如下两个方法，这个才能顺利的被序列化编码存储和读取。

//从nsobject解析回来
init(coder aDecoder:NSCoder!){
    self.name=aDecoder.decodeObjectForKey("Name") as String
    self.phone=aDecoder.decodeObjectForKey("Phone") as String
}
 
//编码成object
func encodeWithCoder(aCoder:NSCoder!){
    aCoder.encodeObject(name,forKey:"Name")
    aCoder.encodeObject(phone,forKey:"Phone")
}

具体代码如下：

--- ViewController.swift ---

import UIKit
 
class ViewController: UIViewController {
 
    var dataModel = DataModel()
 
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
         
        //初始化模拟数据
        onCreateData()
    }
     
    //创建模拟数据
    func onCreateData(){
        dataModel.userList.append(UserInfo(name: "张三", phone: "1234"))
        dataModel.userList.append(UserInfo(name: "李四", phone: "1212"))
        dataModel.userList.append(UserInfo(name: "航歌", phone: "3525"))
    }
 
    //保存数据
    @IBAction func saveData(sender:AnyObject) {
        dataModel.saveData()
    }
     
    //读取数据
    @IBAction func loadData(sender:AnyObject) {
        dataModel.loadData()
    }
     
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

--- DataModel.swift ---

import UIKit
 
class DataModel: NSObject {
     
    var userList = [UserInfo]()
     
    override init(){
        super.init()
        println("沙盒文件夹路径：(documentsDirectory())")
        println("数据文件路径：(dataFilePath())")
    }
     
    //保存数据
    func saveData() {
        var data = NSMutableData()
        //申明一个归档处理对象
        var archiver = NSKeyedArchiver(forWritingWithMutableData: data)
        //将lists以对应Checklist关键字进行编码
        archiver.encodeObject(userList, forKey: "userList")
        //编码结束
        archiver.finishEncoding()
        //数据写入
        data.writeToFile(dataFilePath(), atomically: true)
    }
     
    //读取数据
    func loadData() {
        //获取本地数据文件地址
        let path = self.dataFilePath()
        //声明文件管理器
        let defaultManager = NSFileManager()
        //通过文件地址判断数据文件是否存在
        if defaultManager.fileExistsAtPath(path) {
            //读取文件数据
            let data = NSData(contentsOfFile: path)
            //解码器
            let unarchiver = NSKeyedUnarchiver(forReadingWithData: data!)
            //通过归档时设置的关键字Checklist还原lists
            userList = unarchiver.decodeObjectForKey("userList") as Array
            //结束解码
            unarchiver.finishDecoding()
        }
    }
     
    //获取沙盒文件夹路径
    func documentsDirectory()->String {
        var paths = NSSearchPathForDirectoriesInDomains(
            NSSearchPathDirectory.DocumentationDirectory,NSSearchPathDomainMask.UserDomainMask,true)
        var documentsDirectory:String = paths.first as String
        return documentsDirectory
    }
     
    //获取数据文件地址
    func dataFilePath ()->String{
        return self.documentsDirectory().stringByAppendingString("userList.plist")
    }
}

--- UserInfo.swift ---

import UIKit
 
class UserInfo: NSObject {
    var name:String
    var phone:String
     
    //构造方法
    init(name:String="",phone:String=""){
        self.name = name
        self.phone = phone
        super.init()
    }
     
    //从nsobject解析回来
    init(coder aDecoder:NSCoder!){
        self.name=aDecoder.decodeObjectForKey("Name") as! String
        self.phone=aDecoder.decodeObjectForKey("Phone") as! String
    }
     
    //编码成object
    func encodeWithCoder(aCoder:NSCoder!){
        aCoder.encodeObject(name,forKey:"Name")
        aCoder.encodeObject(phone,forKey:"Phone")
    }
}