Question

我正在尝试使用NewtonSoft.Json中的JSONConvert解码从twitter流API获得的JSON

我创建了这个类来模仿twitter状态对象

class tweeter
{
    public string geo { get; set; }
    public string text { get; set; }
    public string name { get; set; }
    public string screen_name { get; set; }
    public string created_at { get; set; }
    public string id { get; set; }

}

然后在我的代码中，我执行以下操作来解码它

try
              {
                  System.Threading.Interlocked.Increment(ref linesRead);
                  var des = JsonConvert.DeserializeObject<tweeter>(e.Line);
                  listBox1.Items.Add(e.Line);

                  dbhelper.insertTweet(des.id,des.screen_name,des.text,des.created_at,"","","", com);

                  listBox1.SelectedIndex = listBox1.Items.Count - 1;

                  listBox1.SelectedIndex = -1;
                  label1.Text = string.Format("Lines Read: {0:F0}", linesRead);
              }
              catch (Exception x)
              {
                  MessageBox.Show(x.Message);
              }

但是，像screen_name这样的嵌套元素总是返回null，如何访问这些嵌套元素？

geo，text，created_at，id等其他根元素正常返回并具有值。

编辑：这是来自Feed {"in_reply_to_status_id":null,"favorited":false,"text":"Haa I'm joking everyone I wish! Need it for #ibiza2012 and #Egypt","in_reply_to_status_id_str":null,"entities":{"hashtags":[{"text":"ibiza2012","indices":[44,54]},{"text":"Egypt","indices":[59,65]}],"urls":[],"user_mentions":[]},"geo":null,"retweet_count":0,"place":null,"truncated":false,"created_at":"Wed Mar 14 15:14:47 +0000 2012","in_reply_to_user_id_str":null,"source":"\u003Ca href=\"http:\/\/twitter.com\/#!\/download\/iphone\" rel=\"nofollow\"\u003ETwitter for iPhone\u003C\/a\u003E","retweeted":false,"in_reply_to_screen_name":null,"coordinates":null,"in_reply_to_user_id":null,"user":{"contributors_enabled":false,"geo_enabled":false,"profile_sidebar_fill_color":"DDEEF6","lang":"en","listed_count":0,"created_at":"Sat Apr 11 17:12:45 +0000 2009","profile_sidebar_border_color":"C0DEED","is_translator":false,"show_all_inline_media":true,"follow_request_sent":null,"verified":false,"url":null,"description":"Ibiza 2012 for openings! Have a bang on that!","default_profile":true,"following":null,"profile_use_background_image":true,"time_zone":null,"profile_text_color":"333333","statuses_count":2513,"notifications":null,"profile_background_image_url_https":"https:\/\/si0.twimg.com\/images\/themes\/theme1\/bg.png","profile_background_image_url":"http:\/\/a0.twimg.com\/images\/themes\/theme1\/bg.png","location":"London","profile_link_color":"0084B4","followers_count":350,"protected":false,"profile_image_url_https":"https:\/\/si0.twimg.com\/profile_images\/1895048740\/image_normal.jpg","profile_image_url":"http:\/\/a0.twimg.com\/profile_images\/1895048740\/image_normal.jpg","default_profile_image":false,"screen_name":"wyatt69","name":"Dean Wyatt","favourites_count":0,"profile_background_color":"C0DEED","id":30482455,"id_str":"30482455","profile_background_tile":false,"utc_offset":null,"friends_count":384},"id":179948698397196288,"id_str":"179948698397196288","contributors":null} d":false,"profile_image_url_https":"https:\/\/si0.twimg.com\/profile_images\/1673331511\/logo-for-twitter_normal.png","profile_image_url":"http:\/\/a0.twimg.com\/profile_images\/1673331511\/logo-for-twitter_normal.png","default_profile_image":false,"screen_name":"itwitex","name":"itwitex","favourites_count":0,"profile_background_color":"EBEBEB","id":307251688,"id_str":"307251688","profile_background_tile":false,"utc_offset":3600,"friends_count":0},"id":179948696308432896,"possibly_sensitive_editable":true,"possibly_sensitive":false,"id_str":"179948696308432896","contributors":null}

的示例

Answer 1

为什么不简单地使用JavaScriptSerializer.Deserialize命名空间中的System.Web.Script.Serialization方法反序列化json：

http://msdn.microsoft.com/en-us/library/ee191864.aspx

Answer 2

我最近不得不为应用程序的某些内部测试做类似的事情。我用类似下面的内容处理了这种情况：

[DataContract]
class Tweeter
{
    [DataMember]
    public string geo {get;set;}
    [DataMember]
    public User user {get;set;}
}

[DataContract]
class User
{
    [DataMember]
    public string screen_name {get;set;}
}

class Converter
{
    public Tweeter ConvertJson(string json)
    {
        DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(Tweeter));

        using (MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(json)))
        {
            return serializer.ReadObject(ms) as Tweeter;
        }
    }
}

如何在C＃中解码JSON

2 个答案: