【资料图】

Swift下将网络返回json数据转换成struct假如网络请求返回的数据结构是一个深层嵌套的Json首先要通过key-value取出这个json中的数据源

// 将返回的json字符串转Dictorylet 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)")    }}

数模转换

// 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        }    }}

字典与struct互相转换

将字典转换成struct模型根据网络返回的Dictory，从里面取出数组widgets: Array<[String: Any]>1.map遍历数组，拿到每一个数组元素字典2.处理每个元素，先使用JSONSerialization.data(withJSONObject:将字典转成data，3.再使用JSONDecoder().decode(ContactSimpleModel.self, from: data)将data转成struct结构体。4.使用struct模型

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

struct模型转字典也可以通过给Encodable协议加默认实现，提供便捷Struct转字典方法

// 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本地缓存假如没有使用数据库，通过UserDefaults或者Plist文件保存。使用data进行保存到UserDefaults

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)}

使用Dictionary保存到Plist文件本地文件处理路径判断，创建目录用Url.path创建目录案例

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    }()

写文件要用Url.absoluteStringswift中保存plist文件，使用NSDictionary进行保存

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: ())

zip文件解压

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)")    }}

先缓存后使用，提高用户体验SDWebImage的先预下载图片，等启动时直接使用缓存的方法

//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

注意：对于可选类型的数组，如果没有拆包就map, 那么闭包的入参是拆包的数组

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