Swift下Data处理全流程：从网络下载，数模转换，本地缓存到页面使用

// 将返回的json字符串转Dictory
let json = """
{
    "name": "jack",
    "age": 20,
    "description": "A student."
}
""".data(using: .utf8)!
if let jsonData = jsonString.data(using: .utf8) {
    do {
        let json = try JSONSerialization.jsonObject(with: jsonData, options: [])
        if let dictionary = json as? [String: Any],
           let key2 = dictionary["key2"] as? [String: Any],
           let innerKey2 = key2["key2"] as? [String: Any],
           let value = innerKey2["key1"] as? String {
            print(value) // 输出"value3"
        }
    } catch {
        print("解析JSON数据失败：(error)")
    }
}

// 定义数据类型，遵守Codable协议
// 注意定义的类型与接口返回对应，否则JSONSerialization时崩溃
// Struct模型可以根据json中的数据关系对应嵌套
struct ContactSimpleModel: Codable {
    var relation: String
    var name: String

    struct ContactSimpleModel1: Codable {
    var relation: String
    var name: String

        struct ContactSimpleModel2: Codable {
        var relation: String
        var name: String
        }

    }
}

let decoder = JSONDecoder()
let resList = try widgets.map { (item) -> AdJsonModel in
    let data = try JSONSerialization.data(withJSONObject: item, options: [])
    let res = try decoder.decode(AdJsonModel.self, from: data)
    return res
}
return resList

// 扩展 Encodable 协议
extension Encodable {
    var dictionary: [String: Any]? {
        if let data = try? JSONEncoder().encode(self) {
            if let dict = try? JSONSerialization.jsonObject(with: data) as? [String: Any] {
                return dict
            }
            return nil
        }
        return nil
    }

}

struct Person: Codable {
    var name: String
    var age: Int
}

var people = [Person(name: "John", age: 30), Person(name: "Mary", age: 25)]
//转成data保存
let data = try! JSONEncoder().encode(people)
UserDefaults.standard.set(data, forKey: "peopleData")
//取
if let data = UserDefaults.standard.data(forKey: "peopleData") {
    let people = try! JSONDecoder().decode([Person].self, from: data)
}

    lazy var adListDirPath: String? = {
        let documentDic = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first
        let adUrl = documentDic?.appendingPathComponent(":ad")
        if let adUrlSub = adUrl {
            var isDic: ObjCBool = ObjCBool(false)
            // 判断adUrlSub.path路径是否存在，如果是文件路径则isDic=false, 如果是目录路径isDic=true
            if FileManager.default.fileExists(atPath: adUrlSub.path, isDirectory: &isDic) && isDic.boolValue {
                return adUrlSub.absoluteString
            }
            
            do {
                // 如果路径不存在，则创建本地路径，withIntermediateDirectories: true表示如果路径中间有未创建的，则把中间的目录也创建
                try FileManager.default.createDirectory(at: adUrlSub, withIntermediateDirectories: true, attributes: nil)
                return adUrlSub.absoluteString
            } catch {
                Logger.error(":adDataManager", content: error.localizedDescription)
                return nil
            }
        }
        return nil
    }()

1.先删除历史文件
 do {
    try FileManager.default.removeItem(at: filePathUrl)
    return true
} catch {
    Logger.error(":adDataManager", content: error.localizedDescription)
    return false
}
2.保存新文件
NSDictionary(object: adList, forKey: adListRootKey).write(to: filePathUrl, atomically: true)
3.读取本地文件
let dict = try NSDictionary(contentsOf: filePathUrl, error: ())

  func unzipFile() {
    let zipPath = "/path/to/zip/file"
    let destinationPath = "/path/to/destination/folder"
    do {
        try ZipArchive.unzipFile(atPath: zipPath, toDestination: destinationPath)
    } catch {
        print("Error unzipping file: (error.localizedDescription)")
    }
}

//0.自定义设置缓存大小
URLCache.shared = URLCache(memoryCapacity: 10 * 1024 * 1024, diskCapacity: 50 * 1024 * 1024, diskPath: nil)
//1.缓存
SDWebImage批量下载图片
SDWebImagePrefetcher.shared().prefetchURLs方法下载的图片本地路径默认是Library/Caches/com.hackemist.SDWebImageCache.default目录下的缓存文件。
可以通过SDWebImageManager.shared().imageCache.diskCachePath方法获取具体路径。
//2.使用
在UIImageView加载图片时，使用AAImageView.sd_setImage(with: url, placeholderImage: nil)进行价值

let list = dict[adListRootKey] as? Array
if let listSub = list {
    let decoder = JSONDecoder()
    let resList = listSub.map { (item) -> AdJsonModel? in