JSON Twitter List in C#.net
My code is below. I am not able to extract the 'name' and 'query' lists from the JSON via a DataContracted Class (below) I have spent a long time trying to work this one out,开发者_运维技巧 and could really do with some help...
My Json string:
{"as_of":1266853488,"trends":{"2010-02-22
15:44:48":[{"name":"#nowplaying","query":"#nowplaying"},{"name":"#musicmonday","query":"#musicmonday"},{"name":"#WeGoTogetherLike","query":"#WeGoTogetherLike"},{"name":"#imcurious","query":"#imcurious"},{"name":"#mm","query":"#mm"},{"name":"#HumanoidCityTour","query":"#HumanoidCityTour"},{"name":"#awesomeindianthings","query":"#awesomeindianthings"},{"name":"#officeformac","query":"#officeformac"},{"name":"Justin
Bieber","query":"\"Justin Bieber\""},{"name":"National
Margarita","query":"\"National Margarita\""}]}}
My code:
WebClient wc = new WebClient();
wc.Credentials = new NetworkCredential(this.Auth.UserName, this.Auth.Password);
string res = wc.DownloadString(new Uri(link));
//the download string gives me the above JSON string - no problems
Trends trends = new Trends();
Trends obj = Deserialise<Trends>(res);
private T Deserialise<T>(string json)
{
T obj = Activator.CreateInstance<T>();
using (MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(json)))
{
DataContractJsonSerializer serialiser = new DataContractJsonSerializer(obj.GetType());
obj = (T)serialiser.ReadObject(ms);
ms.Close();
return obj;
}
}
[DataContract]
public class Trends
{
[DataMember(Name = "as_of")]
public string AsOf { get; set; }
//The As_OF value is returned - But how do I get the
//multidimensional array of Names and Queries from the JSON here?
}
I've run into this very issue while developing Twitterizer. The issue is that the dataset isn't in a traditional object-oriented design.
If you were to map that as objects, you would see:
object root int as_of object trends array[object] <date value of as_of> string query string name
As you can see, the trend object has a property that's name changes. The name is based on the as_of date value. As such, it can't be automatically deserialized.
My first solution was to use System.Web.Script.Serialization.JavaScriptSerializer.DeserializeObject(). That method returns a hierarchy of weakly typed, nested dictionary instances. I then stepped through the results myself.
internal static TwitterTrendTimeframe ConvertWeakTrend(object value)
{
Dictionary<string, object> valueDictionary = (Dictionary<string, object>)value;
DateTime date = new DateTime(1970, 1, 1, 0, 0, 0).AddSeconds((int)valueDictionary["as_of"]);
object[] trends = (object[])((Dictionary<string, object>)valueDictionary["trends"])[date.ToString("yyyy-MM-dd HH:mm:ss")];
TwitterTrendTimeframe convertedResult = new TwitterTrendTimeframe()
{
EffectiveDate = date,
Trends = new Collection<TwitterTrend>()
};
for (int i = 0; i < trends.Length; i++)
{
Dictionary<string, object> item = (Dictionary<string, object>)trends[i];
TwitterTrend trend = new TwitterTrend()
{
Name = (string)item["name"]
};
if (item.ContainsKey("url"))
{
trend.Address = (string)item["url"];
}
if (item.ContainsKey("query"))
{
trend.SearchQuery = (string)item["query"];
}
convertedResult.Trends.Add(trend);
}
return convertedResult;
}
It's ugly, but it worked.
I've since embraced the use of Json.NET for it's speed and simplicity.
have you considered using JSON.net ?
Consider this example:
public struct TwitterResponse
{
public int32 as_of;
public Trend[] Trends;
}
public struct Trends
{
public String name;
public String query;
}
Trend[] obj = JavaScriptConvert.DeserializeObject<TwitterResponse>( res ).Trends;
Probably needs finetuning, but that's the general idea on how to do it.
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