9.8、 NSUserDefaults

viewController

//
//  ViewController.swift
//  06_NSUserDefaults
//
//  Created by gaokunpeng on 16/7/4.
//  Copyright © 2016年 apple. All rights reserved.
//

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        //NSUserDefaults的使用,NSUserDefaults使用的是单例对象
        //1.获取
        let btn = UIButton(type: .system)
        btn.frame = CGRect(x: 100, y: 200, width: 100, height: 40)
        btn.setTitle("获取", for: UIControlState())
        btn.addTarget(self, action: #selector(clickBtn), for: .touchUpInside)
        self.view.addSubview(btn)
        btn.tag = 101
        
        //2.存储
        let saveBtn = UIButton(type: .system)
        saveBtn.frame = CGRect(x: 100, y: 300, width: 100, height: 40)
        saveBtn.setTitle("存储", for: UIControlState())
        saveBtn.addTarget(self, action: #selector(saveAction), for: .touchUpInside)
        self.view.addSubview(saveBtn)
        
        //3.删除
        let deleteBtn = UIButton(type: .system)
        deleteBtn.frame = CGRect(x: 100, y: 400, width: 100, height: 40)
        deleteBtn.setTitle("删除", for: UIControlState())
        deleteBtn.addTarget(self, action: #selector(deleteAction), for: .touchUpInside)
        self.view.addSubview(deleteBtn)
    }
    //存储
    func saveAction(){
//NSUserDefaults适合存储轻量级的本地客户端数据，比如记住密码功能，要保存一个系统的用户名、密码。使用NSUserDefaults是首选。下次再登陆的时候就可以直接从NSUserDefaults里面读取上次登陆的信息。
//NSUserDefaults支持的数据格式也很多，有：Int，Float，Double，BOOL，甚至AnyObject类型。
        
//1、获取单例对象
        let ud = UserDefaults.standard
//2、对原生数据类型的储存和读取
        ud.set("张三", forKey: "name")
        //存储字典
        var person = [String:Any]()
        person["name"] = "aixi"
        ud.set(person, forKey: "PERSON")
//3，系统对象的存储与读取 UIImage
//        系统对象实现存储，需要通过archivedDataWithRootObject方法转换成NSData为载体，才可以存储。下面以UIImage对象为例：
        let image = UIImage(named: "2")
        let imageData:NSData = NSKeyedArchiver.archivedData(withRootObject: image ?? "3") as NSData
        ud.set(imageData, forKey: "imageData")
//        自定义对象的存储和读取
//        如果想要存储自己定义的类，首先需要对该类实现NSCoding协议来进行归档和反归档（序列号和反序列化）。即该类内添加func encodeWithCoder(_encoder:NSCoder)方法和init(coder decoder:NSCoder)方法，并继承协议，然后将属性进行转换。
        //自定义对象存储
        let model = PersonModel(names: "WeiWei", ages: "18", weights: 100)
        //实例对象转换成NSData
        let modelData = NSKeyedArchiver.archivedData(withRootObject: model)
        //存储NSData对象
        ud.set(modelData, forKey: "modelData")

        //使用扩展存储
        ud.saveCustomObject(customObject: model, key: "extensionDuixiang")
        //同步到文件
        ud.synchronize()
        /*
         NSUserDefaults实现的原理
         系统里面有一个文件来存储NSUserDefaults里面的数据
         在程序启动的时候，系统将这个文件里面的所有数据读到内存里面
         我们修改的数据只是修改了内存里面的数据
         但是这个数据没有同步到文件里面,下一次使用的时候这个数据就没有
         所以在程序结束之前我们都应该将内存里面的数据同步到文件
         */
    }
    //获取
    func clickBtn(){
        let ud = UserDefaults.standard
        let name = ud.object(forKey: "name")
        //获取字符串
        if let tmpName = name {
            print("获取字符串",tmpName)
            let alert = UIAlertController(title: "温馨提示", message: "获取到值", preferredStyle: .alert)
            alert.addAction(UIAlertAction(title: "ok", style: .default, handler: nil))
            self.present(alert, animated: true, completion: {
                print("提示弹出后调用打印函数")
            })
        }
        //获取字典中的值
        let person = ud.object(forKey: "PERSON")
        if var perDict:Dictionary = person as? Dictionary<String, Any> {
            print("获取字典中的值",perDict["name"]!)
        }
        
        //UIImage对象读取
        //获取NSData
        let objData = ud.object(forKey: "imageData")
        if let imageData:NSData = objData  as? NSData {
            //还原对象
            let myImage = NSKeyedUnarchiver.unarchiveObject(with: imageData as Data) as! UIImage
            let btn:UIButton = self.view.viewWithTag(101) as! UIButton
            btn.setBackgroundImage(myImage, for: .normal)
            print("获取NSData",myImage)
        }

        //自定义对象读取
        let modelData = ud.object(forKey: "modelData")
        if let models = modelData {
            let myModel = NSKeyedUnarchiver.unarchiveObject(with: models as! Data) as! PersonModel
            print("自定义对象的值",myModel.name,myModel.age,myModel.weight)
        }
        
        //使用扩展获取
       let extenModel = ud.getCustomObject(forKey: "extensionDuixiang")
        if let dataModels:PersonModel = extenModel as? PersonModel {
            print("扩展的user default==",dataModels.age)
        }
    }
    //删除
    func deleteAction(){
        let ud = UserDefaults.standard
        ud.removeObject(forKey: "name")
        ud.removeObject(forKey: "PERSON")
        ud.removeObject(forKey: "imageData")
        ud.removeObject(forKey: "modelData")
        ud.removeObject(forKey: "extensionDuixiang")

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


}

import Foundation
extension UserDefaults {
    //用在登录的时候，存储用户名和密码，和相关全局信息
    //存储
    func saveCustomObject(customObject: NSCoding, key: String) {
        let encodedObject = NSKeyedArchiver.archivedData(withRootObject: customObject)
        self.set(encodedObject, forKey: key)
        self.synchronize()
    }
    //获取
    func getCustomObject(forKey key: String) -> AnyObject? {
        let decodedObject = self.object(forKey: key) as? NSData
        if let decoded = decodedObject {
            let object = NSKeyedUnarchiver.unarchiveObject(with: decoded as Data)
            return object as AnyObject
        }
        return nil
    }
    //移除
    func removeCustomObject(key: String){
        self.removeObject(forKey: key)
        self.synchronize()
    }
}

import UIKit

class PersonModel: NSObject,NSCoding {
var name:String
var age:String
var weight:Int
init(names:String,ages:String,weights:Int) {
self.name = names
self.age = ages
self.weight = weights
super.init()
}
//当我们在子类定义了指定初始化器(包括自定义和重写父类指定初始化器)，那么必须显示实现required init?(coder aDecoder: NSCoder)，而其他情况下则会隐式继承，我们可以不用理会。
//提供一个解码器解码数据，通过解码数据来初始化类变量
// MARK:- 处理需要解档的字段
required init(coder aDecoder:NSCoder){
self.name = aDecoder.decodeObject(forKey: "name") as! String
self.age = aDecoder.decodeObject(forKey: "age") as! String
self.weight = Int(aDecoder.decodeInt32(forKey: "weight"))
}
//提供一个编码器编码数据
// MARK:- 处理需要归档的字段
func encode(with aCoder: NSCoder) {
aCoder.encode(name,forKey:"name")
aCoder.encode(age,forKey:"age")
aCoder.encode(weight,forKey:"weight")
}
}