如何將json反序列化爲c中的對象＃

Question

無法將json反序列化爲對象。嘗試使用DataContractJsonSerializer。
這是我如何使用它
不知道如何應付呢..
CLASS

[Serializable] 
    public class user 
    { 
     public user() { } 
     public user(string _uid, string _first_name, string _last_name, string _online) 
     { 
      this._uid = _uid; 
      this._first_name = _first_name; 
      this._last_name = _last_name; 
      this._online = _online; 
     } 

     string _uid; 
     string _first_name; 
     string _last_name; 
     string _online; 

     [DataMember] 
     public string uid 
     { 
      get { return _uid; } 
      set { _uid = value; } 
     } 

     [DataMember] 
     public string first_name 
     { 
      get { return _first_name; } 
      set { _first_name = value; } 
     } 

     [DataMember] 
     public string last_name 
     { 
      get { return _last_name; } 
      set { _last_name = value; } 
     } 
     [DataMember] 
     public string online 
     { 
      get { return _online; } 
      set { _online = value; } 
     } 
    } 

DataContractJsonSerializer使用

 WebRequest w = WebRequest.Create(string.Format("https://api.vk.com/method/friends.get?uid=6631031&fields=uid,first_name,last_name&access_token={0}",_accesstoken)); 
     Stream stream = w.GetResponse().GetResponseStream(); 

     //StreamReader sread = new StreamReader(stream);//here i can get the result into a string 
     //string sLine = sread.ReadLine();    //to make sure the result is valid json 

     DataContractJsonSerializer json = new DataContractJsonSerializer(typeof(user[])); 
     var result = (user[]) json.ReadObject(stream); 

比如我的JSON

"{\"response\":[{\"uid\":779358,\"first_name\":\"Dark\",\"last_name\":\"Knight\",\"online\":0},{\"uid\":1023931,\"first_name\":\"Екатерина\",\"last_name\":\"Гаврилова\",\"online\":0},{\"uid\":2475856,\"first_name\":\"Даша\",\"last_name\":\"Матвеева\",\"online\":0},......]}" 

Answer 1

你可以定義包含爲了user[]類型的response屬性包裝對象，以反映您的JSON結構：

[DataContract] 
public class Result 
{ 
    [DataMember] 
    public user[] response { get; set; } 
} 

然後：

DataContractJsonSerializer json = new DataContractJsonSerializer(typeof(Result)); 
Result result = (Result)json.ReadObject(stream); 
user[] users = result.response;