如何在iOS Swift中使用MultipartFormData将zip文件上传到服务器？

Question

我正在尝试将zipfile上传到服务器。当我尝试将zip文件上传到服务器时，文件未成功上传。我从服务器收到错误。在服务器端，userid与文件名分开。

实际的服务器JSON响应是：

{"error":{"login":"Sorry,Failed to Login "}}

我是multipart/form-data的新手，所以我不知道这个问题背后的原因。 这是我的代码：

func uploadData() {
    let headers: HTTPHeaders = [
        "Content-type": "multipart/form-data"
    ]

    var username:String = username_textfield.text!
    var password:String = password_textfield.text!

    let fileManager = FileManager()

    let paths = (NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as NSString).appendingPathComponent("/cropsapdb_up_\(useridsaved).zip")
    var filepath = paths

    var sourceURL = URL(fileURLWithPath: filepath)
    var zipnewdata:NSData = NSData()

    zipnewdata = FileManager.default.contents(atPath: filepath) as! NSData

    let parameters = ["unm2": username,"pass2":password,"ufile":filepath]

    Alamofire.upload(multipartFormData: { multipartFormData in
        multipartFormData.append( zipData, withName: "cropsapdb_up_\(self.useridsaved)", fileName: "cropsapdb_up_\(self.useridsaved).zip", mimeType: "application/zip")
        for (key, value) in parameters {
            multipartFormData.append((value.data(using: String.Encoding.utf8)!), withName: key)
        }
    }, usingThreshold: UInt64.init(), to: "myurl", method: .post, headers: headers) { (result) in
        switch result{
        case .success(let upload, _, _):
            upload.responseJSON { response in
                print("Succesfully uploaded = \(response.data)")
                if let JSON = response.result.value
                {
                    print("JSON: \(JSON)")
                }
                if let err = response.error{
                    print("response error")
                    return
                }

            }
        case .failure(let error):
            print("Error in upload: \(error.localizedDescription)")

        }
    }
}