如何从 HttpClient 解析 JSON 字符串

我通过调用外部API得到一个JSON结果.

        HttpClient client = new HttpClient();
        client.BaseAddress = new Uri(url);
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
        HttpResponseMessage response = client.GetAsync(url).Result;

        if (response.IsSuccessStatusCode)
        {
            var result  = response.Content.ReadAsStringAsync().Result;
            var s = Newtonsoft.Json.JsonConvert.DeserializeObject(result);
            return "Success";
        }
        else
        {
            return "Fail";
        }

The result in line var s = Newtonsoft.Json.JsonConvert.DeserializeObject(result); I am getting is like:

 {{
  "query": "1",
  "topScoringIntent": {
    "intent": "1",
    "score": 0.9978111,
    "actions": [
      {
        "triggered": false,
        "name": "1",
        "parameters": []
      }
    ]
  },
  "entities": [],
  "dialog": {
    "prompt": "1",
    "parameterName": "1",
    "parameterType": "1::1",
    "contextId": "11",
    "status": "1"
  }
}}

我用的是HttpClient美元.我在访问prompt键值时遇到了困难.我想从dialog分中拿prompt分.我怎么才能买到呢？