POST with/ JSON Body - Swift 3 - 片段？

Question

我只是想通过 Swift3 httprequest 发送一个 JSON 字符串。

尝试使用字典和转义字符串 ...

func getToken(successHandler: @escaping (Any) -> Void, errorHandler: @escaping (Any) -> Void) {

    var request = URLRequest(url: URL(string: "http://my-api.domain.com/getToken")!)

    request.httpMethod = "POST"

    request.setValue("application/json", forHTTPHeaderField: "Content-Type")

    do
    {
        // try with Dictionary
        let bodyJson: [String: String] = [
            "username": "theusername"
        ]
        let bodyJsonData = try JSONSerialization.data(withJSONObject: bodyJson, options: [])

        // try with escaped String
        let jsonString = "{" +
            "\"username\": \"theusername\"," +
        "}"
        let jsonStringData = jsonString.data(using: String.Encoding.utf8)


        //request.httpBody = bodyJsonData
        request.httpBody = jsonStringData


        let task = URLSession.shared.dataTask(with: request) { data, response, error in
            guard error == nil else {
                print(error)
                errorHandler(error)
                return
            }
            guard let data = data else {
                print("Data is empty")
                errorHandler("Data is empty")
                return
            }

            var json: Any? = nil
            do
            {
                json = try JSONSerialization.jsonObject(with: data, options: [])

                DispatchQueue.main.asyncAfter(deadline: .now()) {
                    successHandler(json)
                }
            }
            catch let error as NSError {
                errorHandler(error)
            }
        }

        task.resume()
    }
    catch
    {
        errorHandler(error)
    }
}

我不断得到：

处理错误：错误域=NSCocoaErrorDomain Code=3840 "JSON 文本没有 不以数组或对象开头，并允许未设置片段的选项。” UserInfo={NSDebugDescription=JSON 文本不是以数组开头或 允许未设置片段的对象和选项。}

我找不到如何尝试允许片段，所有示例/教程都是针对 Swift2.x 的：/

不知道该怎么办！

Answer 1

// prepare json data
  let mapDict = [ "1":"First", "2":"Second"]

  let json = [ "title":"ABC" , "dict": mapDict ] as [String : Any]

  do {
     let jsonData = try JSONSerialization.data(withJSONObject: json, options: .prettyPrinted)

     // create post request
     let endpoint: String = "https://yourAPI"
     let session = URLSession.shared
     let url = NSURL(string: endpoint)!
     let request = NSMutableURLRequest(url: url as URL)
     request.httpMethod = "POST"

     // insert json data to the request
     request.httpBody = jsonData


     let task = session.dataTask(with: request as URLRequest){ data,response,error in
        if error != nil{
           print(error?.localizedDescription)
           return
        }
     }
     task.resume()
  } catch {
     print("bad things happened")
  }