calling rest api on client side c#

Question

I am new to api stuff. I want to get the result of this api(http://services.groupkt.com/country/get/all) in c# code. can you help me by suggesting any code and tutorial as well. thanks i have tried this code but it doesnot work.

public async Task DownloadData()
{
    string url = string.Format("http://services.groupkt.com/country/get/all");

    HttpClient client = new HttpClient();
    client.DefaultRequestHeaders.Add("Accept", "application/json");

    var jsonString = await client.GetStringAsync(url);

    JToken token = JToken.Parse(jsonString);

    foreach (var item in token)
    {
        txtarea.Value= item.ToString();
    }
}

"it doesnot work" has several meanings. Are you getting any compiler error, runtime error, or you are not getting the expected results? — Thangadurai, Feb 01 '17 at 06:09
i am trying to display result in a textarea but it doesnot show any result. — waqar ahmed somra, Feb 01 '17 at 06:11
Use a browser to visit that url and see what you are getting? or you can also use fiddler to test the service url. — Thangadurai, Feb 01 '17 at 06:17
i am getting json format. i am able to get result using jquery but i have to do it in c# — waqar ahmed somra, Feb 01 '17 at 06:19
Use Json2CSharp.com (or the equivalent feature in Visual Studio to paste JSON as a class). Then using `JsonConvert` to deserialize into that object, now you have a class you can deal with. — Ian Mercer, Feb 01 '17 at 06:48

score 3 · Accepted Answer · answered Feb 01 '17 at 07:33

First of all use

client.GetStringAsync(url).Result

instead of

client.GetStringAsync(url)

Second after you received the json, it becomes very simple to parse the result. I saw the previous answeres and they were all using a loop, which is not a good idea in my opinion to parse. Use Newtonsoft.Json library and its very handy in such situations. I've parsed your json response using this library. Make a class of result, i.e.

    public class result
    {
        public string name { get; set; }
        public string alpha3_code { get; set; }
        public string alpha2_code { get; set; }
    }

put this code after getting json response for parsing your json.

JObject jsonResponse = JObject.Parse(jsonString);
JObject objResponse = (JObject)jsonResponse["RestResponse"];
Dictionary<string, JArray> _Data = Newtonsoft.Json.JsonConvert.DeserializeObject<Dictionary<string, JArray>>(objResponse.ToString());
var results = _Data["result"].ToObject<List<result>>();

It works perfectly, I've tested this.

Don't forget to add Newtonsoft.Json AND Newtonsoft.Json.Linq namespaces

been looking for this solution for 2 days.. every other solution was too complex and does not work... thanks mate — asmgx, May 15 '21 at 03:25

Mit Bhatt · Answer 2 · 2017-02-01T06:44:18.940

0

Your code fetches the response correctly. But parsing incorrectly.

Try the below full parsing code.

public async Task DownloadData()
{
    string url = string.Format("http://services.groupkt.com/country/get/all");
    string top_parent_key_name = "RestResponse";
    string second_parent_key_name = "result";
    string field_one_key_name = "name";

    HttpClient client = new HttpClient();
    client.DefaultRequestHeaders.Add("Accept", "application/json");

    var jsonString = await client.GetStringAsync(url);

    JToken token = JToken.Parse(jsonString);

    foreach (var item in token[top_parent_key_name][second_parent_key_name])
    {
        txtarea.InnerText = item[field_one_key_name].ToString();
    }
}

edited Feb 01 '17 at 06:44

answered Feb 01 '17 at 06:17

Mit Bhatt

472
2
11

Just replace your front end control names with this. For example txtarea.Value = item[field_one_key_name].ToString(); – Mit Bhatt Feb 01 '17 at 06:25
i am calling await DownloadData(); in button click function and displaying result in label but its not showing anything – waqar ahmed somra Feb 01 '17 at 06:26
Try this `txtarea.InnerText = item[field_one_key_name].ToString();` – Mit Bhatt Feb 01 '17 at 06:31
Maybe this could help, it suggests casting to JObject then using Properties() to get the values: [accessing all items in the JTOKEN, json.net](http://stackoverflow.com/a/16797673/6741868) – Keyur PATEL Feb 01 '17 at 06:38

Jens · Answer 3 · 2017-02-01T07:02:32.853

Just to add, I would prefer dynamics here so the code communicates more clearly.

public async Task DownloadData()
{
    string url = $"http://services.groupkt.com/country/get/all";

    HttpClient client = new HttpClient();
    client.DefaultRequestHeaders.Add("Accept", "application/json");

    string response = await client.GetStringAsync(url);

    dynamic json = JToken.Parse(response);

    foreach (var item in token.RestResponse.result)
    {
        //Note: Your over writing the text here for each item you pass
        //      Did you mean to concat instead? += "\n\r" + item.name;
        txtarea.InnerText = item.ToString();
    }
}

Now as for just doing txtarea.InnerText = ... in a question you labeled with "ASP.NET-Web-Api" seems a bit odd, is it an ASP.NET MVC with Web Api or a more classic Web Forms application?

calling rest api on client side c#

3 Answers3