一. UserDefaults 常用使用場景

1. 存儲(chǔ)用戶偏好設(shè)置
2. 存儲(chǔ)緩存信息
3. 輕量級(jí)數(shù)據(jù)存儲(chǔ)

UserDefaults會(huì)在本地存儲(chǔ)數(shù)據(jù)，使得程序進(jìn)程結(jié)束后，仍能保留數(shù)據(jù)，在下次進(jìn)入App后，這些數(shù)據(jù)可以被使用。

二. 默認(rèn)支持存儲(chǔ)的數(shù)據(jù)類型

NSArray NSData NSDate NsDictionary NsString NSNumber(Bool Integer Float Double)

三. 使用方法

1.添加(set)

//獲取UserDefaults實(shí)例
let userDefaults = UserDefaults.standard
userDefaults.set(123, forKey: "defaultKey")
//將存儲(chǔ)的偏好存儲(chǔ)同步到ROM中
userDefaults.synchronize()

2. 讀取

var readInt = userDefaults.integer(forKey: "defaultKey")

3. 修改
   通過key值直接set覆蓋即可

4. 刪除

userDefaults.removeObject(forKey: "defaultKey")
//刪除所有
//獲取應(yīng)用域的所有字符串
let appDomainString = Bundle.main.bundleIdentifier
userDefaults.removePersistentDomain(forName: appDomainString)

原生數(shù)據(jù)的存儲(chǔ):

let userDefault = UserDefaults.standard

//Any
userDefault.set("hangge.com", forKey: "Object")
let objectValue:Any? = userDefault.object(forKey: "Object")

//Int類型
userDefault.set(12345, forKey: "Int")
let intValue = userDefault.integer(forKey: "Int")

//Float類型
userDefault.set(3.2, forKey: "Float")
let floatValue = userDefault.float(forKey: "Float")

//Double類型
userDefault.set(5.2240, forKey: "Double")
let doubleValue = userDefault.double(forKey: "Double")

//Bool類型
userDefault.set(true, forKey: "Bool")
let boolValue = userDefault.bool(forKey: "Bool")

//URL類型
userDefault.set(URL(string:"http://hangge.com")!, forKey: "URL")
let urlValue = userDefault.url(forKey: "URL")

//String類型
userDefault.set("hangge.com", forKey: "String")
let stringValue = userDefault.string(forKey: "String")

//NSNumber類型
var number = NSNumber(value:22)
userDefault.set(number, forKey: "NSNumber")
number = userDefault.object(forKey: "NSNumber") as! NSNumber

//Array類型
var array:Array = ["123","456"]
userDefault.set(array, forKey: "Array")
array = userDefault.array(forKey: "Array") as! [String]

//Dictionary類型
var dictionary = ["1":"hangge.com"]
userDefault.set(dictionary, forKey: "Dictionary")
dictionary = userDefault.dictionary(forKey: "Dictionary") as! [String : String]

四. 對(duì)自定義數(shù)據(jù)的存儲(chǔ)

let userDefault = UserDefaults.standard

//自定義對(duì)象存儲(chǔ)
let model = UserInfo(name: "航歌", phone: "3525")
//實(shí)例對(duì)象轉(zhuǎn)換成Data
let modelData = NSKeyedArchiver.archivedData(withRootObject: model)
//存儲(chǔ)Data對(duì)象
userDefault.set(modelData, forKey: "myModel")

//自定義對(duì)象讀取
let myModelData = userDefault.data(forKey: "myModel")
let myModel = NSKeyedUnarchiver.unarchiveObject(with: myModelData!) as! UserInfo
print(myModel)

//----- 自定義對(duì)象類 -----
class UserInfo: NSObject, NSCoding {
    var name:String
    var phone:String

    //構(gòu)造方法
    required init(name:String="", phone:String="") {
        self.name = name
        self.phone = phone
    }

    //從object解析回來
    required init(coder decoder: NSCoder) {
        self.name = decoder.decodeObject(forKey: "Name") as? String ?? ""
        self.phone = decoder.decodeObject(forKey: "Phone") as? String ?? ""
    }

    //編碼成object
    func encode(with coder: NSCoder) {
        coder.encode(name, forKey:"Name")
        coder.encode(phone, forKey:"Phone")
    }
}

五. 進(jìn)階：Swift中安全優(yōu)雅的使用UserDefaults

轉(zhuǎn)載鏈接：http://m.itdecent.cn/p/3796886b4953