arrays - 如何在swift代码中保存一组类

Question

我正在尝试保存一组类，这是我目前的代码:

数组:

var person1 = person(name: "Bob", age: 22)
var person2 = person(name: "John", age: 10)
var array = [person1, person2]

自定义类:

import UIKit

class person: NSObject, NSCoding {

    var name : String
    var age : Int

    init(name: String, age: Int) {
        self.name = name
        self.age = age
    }

    required init (coder aDecoder: NSCoder) {
        name = (aDecoder.decodeObject(forKey: "name") as? String)!
        age = (aDecoder.decodeObject(forKey: "age") as? Int)!
    }

   func encode(with aCoder: NSCoder) {
        aCoder.encode(name, forKey: "name")
        aCoder.encode(age, forKey: "age")
    }
}

保存数组:

let SavedData = NSKeyedArchiver.archivedData(withRootObject: array)

let defaults = UserDefaults.standard

defaults.set(SavedData, forKey: "myPeople")

加载数组:

let saveddata = UserDefaults.standard.object(forKey: "myPeople") as? Data

if saveddata != nil{
    array = (NSKeyedUnarchiver.unarchiveObject(with: saveddata!) as? [person])!
}

错误在 age = (aDecoder.decodeObject(forKey: "age") as? Int)!

这行

Unknown class iewripple in Interface Builder file.

Answer 1

发生错误是因为您正在编码一个 Int 但解码一个失败的 object。

有一个专用方法decodeInteger(forKey。

请遵循类名以大写字母开头，变量名以小写字母开头的命名约定。

class Person: NSObject, NSCoding {

要解决此问题，请将 init(coder 方法更改为

required init(coder aDecoder: NSCoder) {
    name = aDecoder.decodeObject(forKey: "name") as! String
    age = aDecoder.decodeInteger(forKey: "age")
}

强制展开字符串是 100% 安全的，因为该值始终被编码为非可选值。

---

保存数组

let savedData = NSKeyedArchiver.archivedData(withRootObject: array)
UserDefaults.standard.set(savedData, forKey: "myPeople")

加载数组

if let savedData = UserDefaults.standard.object(forKey: "myPeople") as? Data {
    array = NSKeyedUnarchiver.unarchiveObject(with: savedData) as! [Person]
}

如果可选绑定(bind) as?数据成功。