Dictionary<string, object> suggestions = JSONSerializer.Deserialize<Dictionary<string, object>>(jsonStudent)
if (suggestions.Keys.Contains("UserId"))
student["new_mduserid"] = suggestions["UserId"].ToString();//MD用户Id
}多数组的可以用 List<Dictionary<string, object>>
try {
       string json = File.ReadAllText("robotv1.json");
        // 解析json文件
        dynamic jsonObj = Newtonsoft.Json.JsonConvert.DeserializeObject(json);
        Console.WriteLine(jsonObj.Lidar.DefaultBaud);
         // 也可以修改    
         jsonObj.Lidar.DefaultBaud = 123;
          //重修序列化
         string output = Newtonsoft.Json.JsonConvert.SerializeObject(jsonObj, Newtonsoft.Json.Formatting.Indented);
           File.WriteAllText("config.json", output);
    }catch   {}

static void Main(string[] args)
            string jsonData = "{\"name\":\"lily\",\"age\":23,\"addr\":{\"city\":\"guangzhou\",\"province\":\"guangdong\"}}";
            parseToJObject_1(jsonData);
            Console.ReadLine();
        private static void parseToJObject_1(string jsonData)
            JObject jsonObj = JObject.Parse(jsonData);
            string name = jsonObj["name"].ToString();
            string age = jsonObj["age"].ToString();
            string city = ((JObject)jsonObj["addr"])["city"].ToString();
            string province = ((JObject)jsonObj["addr"])["province"].ToString();
            Console.WriteLine("name={0},age={1},city={2},province={3}{4},", name, age, city, province,System.Environment.NewLine);