你需要在swift 3中发送如下请求

You need to send request like below in swift 3

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)
                }
}

Swift 5 与 Alamofire 5:

Swift 5 with Alamofire 5:

AF.request(URL.init(string: url)!, method: .post, parameters: parameters, encoding: JSONEncoding.default, headers: headers).responseJSON { (response) in
        print(response.result)

        switch response.result {

        case .success(_):
            if let json = response.value
            {
                successHandler((json as! [String:AnyObject]))
            }
            break
        case .failure(let error):
            failureHandler([error as Error])
            break
        }
    }