对原生数据类型的储存和读取
let userDefault = UserDefaults.standard
//Any
userDefault.set("hangge.com", forKey: "Object")
let objectValue:Any? = userDefault.object(forKey: "Object")
//Int类型
userDefault.set(12345, forKey: "Int")
let intValue = userDefault.integer(forKey: "Int")
//Float类型
userDefault.set(3.2, forKey: "Float")
let floatValue = userDefault.float(forKey: "Float")
//Double类型
userDefault.set(5.2240, forKey: "Double")
let doubleValue = userDefault.double(forKey: "Double")
//Bool类型
userDefault.set(true, forKey: "Bool")
let boolValue = userDefault.bool(forKey: "Bool")
//URL类型
userDefault.set(URL(string:"http://hangge.com")!, forKey: "URL")
let urlValue = userDefault.url(forKey: "URL")
//String类型
userDefault.set("hangge.com", forKey: "String")
let stringValue = userDefault.string(forKey: "String")
//NSNumber类型
var number = NSNumber(value:22)
userDefault.set(number, forKey: "NSNumber")
number = userDefault.object(forKey: "NSNumber") as! NSNumber
//Array类型
var array:Array = ["123","456"]
userDefault.set(array, forKey: "Array")
array = userDefault.array(forKey: "Array") as! [String]
//Dictionary类型
var dictionary = ["1":"hangge.com"]
userDefault.set(dictionary, forKey: "Dictionary")
dictionary = userDefault.dictionary(forKey: "Dictionary") as! [String : String]
系统对象的存储与读取
以 UILabel 为例
let userDefault = UserDefaults.standard
//UILabel对象存储
//将对象转换成Data流
let label = UILabel()
label.text = "欢迎访问hangge.com"
let labelData = NSKeyedArchiver.archivedData(withRootObject: label)
//存储Data对象
userDefault.set(labelData, forKey: "labelData")
//UILabel对象读取
//获取Data
let objData = userDefault.data(forKey: "labelData")
//还原对象
let myLabel = NSKeyedUnarchiver.unarchiveObject(with: objData!) as? UILabel
print(myLabel)
以 UIImage 为例(它的存储方式,有一定的特殊)
let userDefault = UserDefaults.standard
//UIImage对象存储
//将对象转换成Data流
let image1 = UIImage(named: "apple.png")!
let image2 = UIImage(cgImage: image1.cgImage!, scale: image1.scale,
orientation: image1.imageOrientation)
let imageData = NSKeyedArchiver.archivedData(withRootObject: image2)
//存储Data对象
userDefault.set(imageData, forKey: "imageData")
//UIImage对象读取
//获取Data
let objData = userDefault.data(forKey: "imageData")
//还原对象
let myImage = NSKeyedUnarchiver.unarchiveObject(with: objData!) as? UIImage
print(myImage)
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(序列化和反序列化)。即该类内添加 func encode(with coder: NSCoder) 方法和 init(coder decoder: NSCoder) 方法,将属性进行转换。
let userDefault = UserDefaults.standard
//自定义对象存储
let model = UserInfo(name: "航歌", phone: "3525")
//实例对象转换成Data
let modelData = NSKeyedArchiver.archivedData(withRootObject: model)
//存储Data对象
userDefault.set(modelData, forKey: "myModel")
//自定义对象读取
let myModelData = userDefault.data(forKey: "myModel")
let myModel = NSKeyedUnarchiver.unarchiveObject(with: myModelData!) as! UserInfo
print(myModel)
//----- 自定义对象类 -----
class UserInfo: NSObject, NSCoding {
var name:String
var phone:String
//构造方法
required init(name:String="", phone:String="") {
self.name = name
self.phone = phone
}
//从object解析回来
required init(coder decoder: NSCoder) {
self.name = decoder.decodeObject(forKey: "Name") as? String ?? ""
self.phone = decoder.decodeObject(forKey: "Phone") as? String ?? ""
}
//编码成object
func encode(with coder: NSCoder) {
coder.encode(name, forKey:"Name")
coder.encode(phone, forKey:"Phone")
}
}
删除存储对象
如果删除的数据不存在,不会报错
UserDefaults.standard.removeObject(forKey: "hangge")