iOS解析json中null终极解决方案

只需要在base64转码的时候，添加代码

    static func base64stringtostring(_ string: NSString ) -> NSString {

        let data = Data.init(base64Encoded: string as String, options: Data.Base64DecodingOptions(rawValue: 1))

        

        var text = NSString.init(data: data!, encoding: String.Encoding.utf8.rawValue)

        if text?.isKind(of: NSNull.classForCoder()) == true {

            text = nil

        }

      //  text = text?.replacingOccurrences(of: "null", with: "\"\"") as NSString?

        return text!.replacingOccurrences(of: "<\"\">", with: "") as NSString

    }