Xamarin Web Services

webservice

using System;
using System.Collections.Generic;
using System.Json;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;

namespace Xamarin.WebServicesAsync.Rest.Droid.Client
{
	public class RestClient
	{


		//TODO: Step 1 - Create a REST client
		private const string 
			RestServiceBaseAddress = "http://rxnav.nlm.nih.gov/REST/",
			AcceptHeaderApplicationJson = "application/json";

		private HttpClient CreateRestClient(){
			var client = new HttpClient(){ BaseAddress = new Uri(RestServiceBaseAddress) };

			client.DefaultRequestHeaders.Accept.Add (MediaTypeWithQualityHeaderValue.Parse(AcceptHeaderApplicationJson));

			return client;
		} 

		//TODO: Step 2 - Call the web service and retrieve data
		public async Task<IEnumerable<Model.ConceptProperty>> GetDataAsync(){
			using (var client = CreateRestClient ()) {
				var getDataResponse = await client.GetAsync ("drugs?name=aspirin", HttpCompletionOption.ResponseContentRead);

				//If we do not get a successful status code, then return an empty set
				if (!getDataResponse.IsSuccessStatusCode)
					return Enumerable.Empty<Model.ConceptProperty> ();

				//Stream the response into a JSON Value object
				var jsonResponse = JsonValue.Load(await getDataResponse.Content.ReadAsStreamAsync ());

						//TODO: Step 5 - call to map JSON to model object
						return MapJsonToConceptProperty (jsonResponse);
			}
		}

		//TODO: Step 3 - Convert JSON into model objects
		private IEnumerable<Model.ConceptProperty> MapJsonToConceptProperty(JsonValue json)
		{
			var conceptProperties = new List<Model.ConceptProperty>();

			if(json != null && json.ContainsKey("drugGroup")){
				var drugGroup = json ["drugGroup"];

				if (drugGroup != null && drugGroup.ContainsKey("conceptGroup")){
					foreach (JsonValue conceptGroup in drugGroup["conceptGroup"]) {
						if(conceptGroup.ContainsKey("conceptProperties")){
							foreach (JsonValue conceptProperty in conceptGroup["conceptProperties"]) {
								conceptProperties.Add(
									new Model.ConceptProperty(){
										//TODO: Step 4 - Map the properties from our DTO to custom object
										Name = conceptProperty.ContainsKey("name") 
												? (string)conceptProperty["name"] 
												: String.Empty,
										Synonym = conceptProperty.ContainsKey("synonym") 
												  ? (string)conceptProperty["synonym"] 
												  : String.Empty
									});
							}
						}
					}
				}
			}

			return conceptProperties.OrderBy(cp => cp.Synonym);
		}
	}
}

webservicemodel

using System;
using System.Collections.Generic;
namespace Xamarin.WebServicesAsync.Rest.Droid.Model
{

	public class ConceptProperty
    {
        public string Name { get; set; }

        public string Synonym { get; set; }	
    }

}