"[{\"url\":\"www.baidu.com/img/bd_logo1.png\"}]”
//1.JSON字符串解析：
let resultDic:NSDictionary! = try! JSONSerialization.jsonObject(with: json.data(using:String.Encoding(rawValue:String.Encoding.utf8.rawValue))!, options:JSONSerialization.ReadingOptions.allowFragments) as? NSDictionary
//2.基本数据生成JSON字符串：
//保存城市服务数据到本地：
let cityServicesArray:NSArray! = resultDic["cityServices"] as! NSArray
letcityData = try! JSONSerialization.data(withJSONObject: cityServicesArray, options:JSONSerialization.WritingOptions(rawValue:UInt(0)))
let cityStr:String! = String.init(data: cityData, encoding: .utf8)
