如何在Facebook上发布新的Feed

Question

我是swift的新手，我试图在Facebook的用户墙上发布新的Feed，但是我的api响应在控制台中显示为nil，并且在网络上工作正常，任何帮助都表示赞赏，谢谢。

    @IBAction func upload(_ sender: AnyObject) {
             let user = UserManager.getLoggedInUser()!
             let request = NSMutableURLRequest(url:NSURL(string: "http://www.MYAPI")!as URL)
            let session = URLSession.shared
            request.httpMethod = "POST"
            request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")

            let PostUtctime = DateFormatter()
            PostUtctime.dateFormat = "YYYY-MM-dd'To'HH:mm:ss"
            let str: String = PostUtctime.string(from: Date())
            print("Date = \(str)")

let guidMemberID = user.userID
            print(guidMemberID)
            let paramToSend =  "{\"guidMemberID\":\"\(user.userID)\", \"ImageString\": \", \"strAboutFeed\":\"\(textView.text)\", \"PostUtctime\": \"\(PostUtctime)\"}"

API通常在执行上述行后说明其成功发布或发生错误

             print(textView.text as Any)
            request.httpBody = (paramToSend as AnyObject) as? Data
            session.dataTask(with: request as URLRequest,completionHandler: {

(data, response, error) -> Void in
             guard let _:Data = data
                        else {
                    print(response as Any)
                    return
                    }
                     var json: [String:AnyObject]
                     do {

json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as? NSDictionary as! [String : AnyObject]
                         print(json)
                        if let httpStatus = response as? HTTPURLResponse, httpStatus.statusCode != 200 {
                            // check for http errors
                            print("statusCode should be 200, but is \(httpStatus.statusCode)")
                            print("response = \(String(describing: response))")
                        }

let responseDataDictionary: Dictionary<String,AnyObject> =  try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as! Dictionary<String,AnyObject>
                        print(responseDataDictionary)
                                }
                    catch {
                        print("Error: \(error.localizedDescription)")
                    }
            }).resume()
        }

}

这是，如果代码中有错误部分，感谢您抽出时间。