ios – 带有Alamofire 4的数据的POST请求

2.3上使用自定义编码它运行良好.我转换了我的代码swift 3,我尝试使用paramater编码,但没有工作.这段代码：

public struct MyCustomEncoding : ParameterEncoding {
private let data: Data
init(data: Data) {
    self.data = data
}
public func encode(_ urlRequest: URLRequestConvertible, with parameters: Parameters?) throws -> URLRequest {

    var urlRequest = try urlRequest.asURLRequest()        
    do {            
            urlRequest.httpBody = data
            urlRequest.setValue("application/json", forHTTPHeaderField: "Content-Type")

    } catch {
        throw AFError.parameterEncodingFailed(reason: .jsonEncodingFailed(error: error))
    }

    return urlRequest
}

和Alamofire要求：

let enco : ParameterEncoding = MyCustomEncoding(data: ajsonData)
    Alamofire.request(urlString, method: .post , parameters: [:], encoding: enco , headers: headers).validate()
                .responseJSON { response in
                    switch response.result {
                    case .success:
                        print(response)

                        break
                    case .failure(let error):

                        print(error)
                    }
    }

let urlString = "https://httpbin.org/get"

Alamofire.request(urlString, method: .post, parameters: ["foo": "bar"],encoding: JSONEncoding.default, headers: nil).responseJSON {  
response in
  switch response.result {
                case .success:
                    print(response)

                    break
                case .failure(let error):

                    print(error)
                }
}