我对归档和解档的理解是
归档就是把要保存的内容转成
Data之后写入指定的路径中。
解档就是把指定路径下的Data转成我们需要的数据类型。
写入路径需要保证，路径中所有文件夹存在，并且文件也存在，创建方法如下
1. 创建路径 FileManager.default.createDirectory，中间文件夹路径需要先创建
2. 创建文件 FileManager.default.createFile
3. 写入文件 Data().write(to: url)
对象的归档、解档
iOS 12.0以后一个安全归档协议NSSecureCoding继承自NSCoding，多了一个static var supportsSecureCoding: Bool属性。
Student类，继承自`NSObject`,遵循`NSSecureCoding`协议。
class Student: NSObject, NSSecureCoding {
var name: String?
var age: Int? = 1
var height: CGFloat = 0.5
var weight: CGFloat = 5.0
init(name: String? = nil, age: Int? = nil, height: CGFloat = 1.80, weight: CGFloat = 75) {
self.name = name
self.age = age
self.height = height
self.weight = weight
super.init()
}
/// NSSecureCoding
static var supportsSecureCoding: Bool = true
func encode(with coder: NSCoder) {
coder.encode(name, forKey: "name")
coder.encode(age, forKey: "age")
coder.encode(height, forKey: "height")
coder.encode(weight, forKey: "weight")
}
required init?(coder: NSCoder) {
name = coder.decodeObject(forKey: "name") as? String
age = coder.decodeObject(forKey: "age") as? Int
height = coder.decodeObject(forKey: "height") as! CGFloat
weight = coder.decodeObject(forKey: "weight") as! CGFloat
super.init()
}
override var description: String {
return "name: \(self.name), age: \(self.age), height: \(self.height), weight: \(self.weight)"
}
}
对Student归档和解档
/// 要归档对象
let stu = Student()
/// 归档路径 <路径必须是通过`fileURLWithPath`这个函数创建的>
let pathStu = (NSTemporaryDirectory() as NSString).appendingPathComponent("student.plist")
let urlStu = URL(fileURLWithPath: pathStu)
if #available(iOS 11.0, *) {
do {
/// 归档对象转 Data
let data = try NSKeyedArchiver.archivedData(withRootObject: stu, requiringSecureCoding: true)
/// 写进置顶路径
try data.write(to: urlStu)
} catch {
print("stu 失败 \(error)")
}
} else {
let success = NSKeyedArchiver.archiveRootObject(stu, toFile: pathStu)
print("succ == \(success)")
}
/// 解档
do {
/// 获取路径下的Data
let dataStu = try Data(contentsOf: urlStu)
var stu: Student
/// 把Data 转成 对象
if #available(iOS 11.0, *) {
stu = try NSKeyedUnarchiver.unarchivedObject(ofClass: Student.self, from: dataStu)!
} else {
stu = NSKeyedUnarchiver.unarchiveObject(with: dataStu) as! Student
}
print("\(stu.name), \(stu.score),\(stu.height)")
} catch {
}
数组、字典、字符串等的归档<本地存储>
func archiveSmapleDemo(){
let arr = ["123","111"]
/// 获取本地存储的路径
let pathArr = (NSTemporaryDirectory() as NSString).appendingPathComponent("arr.txt")
let urlArr = URL(fileURLWithPath: pathArr)
do {
/// 转成Data 并且写入数据
let data = try JSONSerialization.data(withJSONObject: arr, options: .prettyPrinted)
try data.write(to: urlArr)
} catch {
}
do {
/// 根据路径取出Data
let dataArr = try Data(contentsOf: urlArr)
/// 解析成数组
let arr = try JSONSerialization.jsonObject(with: dataArr, options: .mutableContainers) as! [String]
print(arr)
} catch {
}
}
自定义对象数组归档、解档
func archiveSmapleDemo(){
let s1 = Student()
let s2 = Student()
let s3 = Student()
let arr = [s1,s2,s3]
let pathArr = (NSTemporaryDirectory() as NSString).appendingPathComponent("arr.data")
let urlArr = URL(fileURLWithPath: pathArr)
/// 归档
do {
let data: Data
/// 转成Data 并且写入本地
/// 自定义对象要用 `NSKeyedArchiver`转成Data
if #available(iOS 11.0, *) {
data = try NSKeyedArchiver.archivedData(withRootObject: arr, requiringSecureCoding: true)
} else {
data = NSKeyedArchiver.archivedData(withRootObject: arr)
}
try data.write(to: urlArr)
} catch {
print("error == \(error)")
}
/// 解档
do {
/// 根据路径取出Data
let dataArr = try Data(contentsOf: urlArr)
if #available(iOS 14.0, *) {
/// 直接解档成 对象数组
if let arr = try NSKeyedUnarchiver.unarchivedArrayOfObjects(ofClass: Student.self, from: dataArr) {
arr.forEach { p in
print("p.desc == \(p.description)")
}
}else {
}
} else {
/// 解档之后转换成对象数组
if let arr = NSKeyedUnarchiver.unarchiveObject(with: dataArr) as? [Student]{
arr.forEach { p in
print("p.desc == \(p.description)")
}
}
}
} catch {
}
}
学习资料：
iOS数组里为自定义对象情况下的归档
