c# - Class with property that can be one of two different types -

i'm developing telegram bot in c# have difficulty implementing message type. according api documentation, chat field can either of type user or of type groupchat. how implement in c#?

so far come following code using newtonsoft.json:

public class update { ....   [jsonproperty("chat")]   public user chat { get; set; }    [jsonproperty("chat")]   public groupchat group_chat { get; set; } .... } 

but doesn't work webapi 2 controller method since deserialize message using frombody attribute:

public async task<httpresponsemessage> post(string token, [frombody] update update) 

(type update has field message of type message)

is there better way implement message type?

since supposed handle seemingly 2 different objects in 1 field don't think can use strongly-typed objects can use dynamic type chat field such as

public class telegram {     public int message_id { get; set; }     public dynamic chat { get; set; } } 

then can access variables , check if null or not understand if it's user or group chat:

static void main(string[] args) {     string json = @"{ ""chat"": { ""id"": 1, ""first_name"": ""my_first_name"", ""last_name"": ""my_last_name"",  ""username"": ""my_username"" }, ""message_id"": 123 }";     var telegram = newtonsoft.json.jsonconvert.deserializeobject<telegram>(json);     string name = telegram.chat.first_name; // name = my_first_name     string title = telegram.chat.title; // title = null }