iOS12解归档

背景：随着H5的发展，老板们认为跨平台的H5可以降低人力成本 ，客户端需求基本都被H5承接，原生就有时间做优化工作，我们发现有很多App系统需要iOS12及以上了，例如大家熟知大型聊天软件。我们也紧跟时代尾巴把最低版本设置为iOS12，就发现了如下警告：

1、'archivedData(withRootObject:)' was deprecated in iOS 12.0: Use +archivedDataWithRootObject:requiringSecureCoding:error: instead

2、'unarchiveObject(with:)' was deprecated in iOS 12.0: Use +unarchivedObjectOfClass:fromData:error: instead

经过查询各种资料简单封装了一个tools结构体，代码如下

struct Tools {

    // iOS 12以上方法
    @discardableResult
    static func saveObject(_ obj:Any?, forKey key:String) -> Bool {
        if key == "" {
            return false
        }
        let userDefalut = UserDefaults.standard
        guard let ob = obj else {
            userDefalut.removeObject(forKey: key)
            return userDefalut.synchronize()
        }
        do {
            let data = try NSKeyedArchiver.archivedData(withRootObject: ob, requiringSecureCoding: false)
            userDefalut.set(data, forKey: key)
            return userDefalut.synchronize()
        } catch let err {
            DLog("文件缓存失败", err)
            return false
        }
    }
    
    // iOS 12以上方法
    @discardableResult
    static func object(forKey key:String, ofClass:[AnyClass]) -> AnyObject? {
        if key == "" {
            return nil
        }
        let userDefalut = UserDefaults.standard
        if let data = userDefalut.object(forKey: key) as? Data {
            do {
                return try NSKeyedUnarchiver.unarchivedObject(ofClasses: ofClass, from: data) as AnyObject
            } catch let err {
                DLog("读取文件缓存失败", err)
            }
        }
        return nil
    }

}

首先们要准备一个商品类，稍后对他解归档

// 商品基类
class ProductModel: NSObject, NSCoding, NSSecureCoding {

    var productId = "" // 商品id
    var productName = "" // 短名

    override init() {
        super.init()
    }
    
   // 必须实现的NSCoding协议方法
    func encode(with aCoder: NSCoder) {
        aCoder.encode(productId, forKey: "productId")
        aCoder.encode(productName, forKey: "productName")
    }
    
    // 必须实现的NSCoding协议方法
    required init?(coder aDecoder: NSCoder) {
        super.init()
        productId = aDecoder.decodeString("productId")
        productName = aDecoder.decodeString("productName")
    }
    
    static var supportsSecureCoding: Bool {
        return true
    }
}

我们写了测试代码如下：

{
    var list = [ProductModel]()
    let p = ProductModel()
    p.productId = "test00001"
    list.append(p)
    Tools.saveObject(list, forKey: "key")

    DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 2, execute: {
        var classList:[AnyClass] = []
        classList.append(NSArray.self)
        classList.append(ProductModel.self)
        classList.append(NSString.self)
        let productList = Tools.getObject1(forKey: "key", ofClass: classList) as? [ProductModel]
        DLog("------>>>>>",productList ?? "productList is nil")
    })
}

NSSecureCoding 这个协议必须实现，不然解档失败，失败信息如下：

["读取文件缓存失败", Error Domain=NSCocoaErrorDomain Code=4864 "This decoder will only decode classes that adopt NSSecureCoding. Class 'Demo.ProductModel' does not adopt it." UserInfo={NSDebugDescription=This decoder will only decode classes that adopt NSSecureCoding. Class 'Demo.ProductModel' does not adopt it.}]

classList.append(NSString.self)这一句必须添加，不然也会报一堆警告，打印信息如下：

2023-04-19 14:13:59.931486+0800 Demo[14059:155507] [general] *** -[NSKeyedUnarchiver validateAllowedClass:forKey:] allowed unarchiving safe plist type ''NSString' (0x7ff863b906b0) [/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/Foundation.framework]' for key 'productId', even though it was not explicitly included in the client allowed classes set: '{(
    "'NSArray' (0x7ff863b7b800) [/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS.simruntime/Contents/Resources/RuntimeRoot/System/Library/Frameworks/CoreFoundation.framework]",
    "'Demo.ProductModel' (0x104c46360) [/Users/adong/Library/Developer/CoreSimulator/Devices/10E1F45C-50C7-49EB-8750-712778B52F58/data/Containers/Bundle/Application/BA1413BF-8D6F-4B13-8E8F-ABBFF57C5AAE/Demo.app]"
)}'. This will be disallowed in the future.