c# Deserialize json into List
Here is a simple solution to get listing of all id's it will a real amount of time though to go through all of them
List<RootObject> rootobject = new List<RootObject>();
using (var webclient = new WebClient())
{
var Ids = webclient.DownloadString(" https://api.guildwars2.com/v2/commerce/listings");
foreach (var id in Ids.Substring(1, s.Length-2).Split(','))
{
string url = string.Format("{0}/{1}","https://api.guildwars2.com/v2/commerce/listings",id);
var res = webclient.DownloadString(url);
var jsonObject = JsonConvert.DeserializeObject<RootObject>(res);
rootobject.Add(jsonObject);
}
}
Comments
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Rien almost 2 years
I have this code that retrieves Json string from API link. The Json is deserialized and returned to a textbox. This works perfectly as long as there is only 1 Json value, being returned more than 1 value it crashes with this error:
Additional information: Cannot deserialize the current JSON array (e.g. [1,2,3]) into type 'GW2_tradingPost.RootObject' because the type requires a JSON object (e.g. {"name":"value"}) to deserialize correctly.
To fix this error either change the JSON to a JSON object (e.g. {"name":"value"}) or change the deserialized type to an array or a type that implements a collection interface (e.g. ICollection, IList) like List that can be deserialized from a JSON array. JsonArrayAttribute can also be added to the type to force it to deserialize from a JSON array.
Doing my research this happens because there is nowhere to deposit the Json since its not an List.
I've have tried this code and various similar ones.
List<RootObject> list = JsonConvert.DeserializeObject<List<RootObject>>(jsonReader.ToString()); return list;
This will return with error:
Error 1 Cannot implicitly convert type 'System.Collections.Generic.List' to 'GW2_tradingPost.RootObject' e:\mega\gw2_tradingpost\gw2_tradingpost\api_request.cs 34
Which i dont fully understand what it means.
Here is my full code.
api_Request.cs
public class api_Request { public RootObject GetApi(string url) { HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url); try { WebResponse response = request.GetResponse(); using (Stream responseStream = response.GetResponseStream()) { StreamReader reader = new StreamReader(responseStream, Encoding.UTF8); var jsonReader = new JsonTextReader(reader); var serializer = new JsonSerializer(); return serializer.Deserialize<RootObject>(jsonReader); } } catch (WebException ex) { WebResponse errorResponse = ex.Response; using (Stream responseStream = errorResponse.GetResponseStream()) { StreamReader reader = new StreamReader(responseStream, Encoding.GetEncoding("utf-8")); String errorText = reader.ReadToEnd(); // log errorText } throw; } } } public class Buy { public int listings { get; set; } public int unit_price { get; set; } public int quantity { get; set; } } public class Sell { public int listings { get; set; } public int unit_price { get; set; } public int quantity { get; set; } } public class RootObject { public int id { get; set; } public List<Buy> buys { get; set; } public List<Sell> sells { get; set; } }
Form1.cs
private void button1_Click(object sender, EventArgs e) { RootObject RootObject = new RootObject(); api_Request api_Request = new api_Request(); richTextBox1.Text = api_Request.GetApi("https://api.guildwars2.com/v2/commerce/listings").id.ToString(); }
In this json is a single ID, so this works fine. https://api.guildwars2.com/v2/commerce/listings/19684
But when retrieving multiple ID's like here, it breaks. https://api.guildwars2.com/v2/commerce/listings