Root Class

Amazon api root class is as following.

    public class AmazonRootobject
    {
        public Itemsearchresponse ItemSearchResponse { get; set; }
    }

    public class Itemsearchresponse
    {
        public string xmlns { get; set; }
        public Operationrequest OperationRequest { get; set; }
        public Items Items { get; set; }
    }

    public class Operationrequest
    {
        public Httpheaders HTTPHeaders { get; set; }
        public string RequestId { get; set; }
        public Arguments Arguments { get; set; }
        public string RequestProcessingTime { get; set; }
    }

    public class Httpheaders
    {
        public Header Header { get; set; }
    }

    public class Header
    {
        public string Name { get; set; }
        public string Value { get; set; }
    }

    public class Arguments
    {
        public Argument[] Argument { get; set; }
    }

    public class Argument
    {
        public string Name { get; set; }
        public object Value { get; set; }
    }

    public class Items
    {
        public Request Request { get; set; }
        public string TotalResults { get; set; }
        public string TotalPages { get; set; }
        public string MoreSearchResultsUrl { get; set; }
        public Item[] Item { get; set; }
    }

    public class Request
    {
        public string IsValid { get; set; }
        public Itemsearchrequest ItemSearchRequest { get; set; }
    }

    public class Itemsearchrequest
    {
        public string Keywords { get; set; }
        public string[] ResponseGroup { get; set; }
        public string SearchIndex { get; set; }
        public string Sort { get; set; }
    }

    public class Item
    {
        public string ASIN { get; set; }
        public string ParentASIN { get; set; }
        public string DetailPageURL { get; set; }
        public Itemlinks ItemLinks { get; set; }
        public Smallimage SmallImage { get; set; }
        public Mediumimage MediumImage { get; set; }
        public Largeimage LargeImage { get; set; }
        public Imagesets ImageSets { get; set; }
        public Itemattributes ItemAttributes { get; set; }
        public OfferSummary OfferSummary { get; set; }
        public Offers Offers { get; set; }

        public Variationsummary VariationSummary { get; set; }
    }

    public class Variationsummary
    {
        public Highestprice HighestPrice { get; set; }
        public Lowestprice LowestPrice { get; set; }
        public Highestsaleprice HighestSalePrice { get; set; }
        public Lowestsaleprice LowestSalePrice { get; set; }
    }

    public class Highestprice
    {
        public string Amount { get; set; }
        public string CurrencyCode { get; set; }
        public string FormattedPrice { get; set; }
    }

    public class Lowestprice
    {
        public string Amount { get; set; }
        public string CurrencyCode { get; set; }
        public string FormattedPrice { get; set; }
    }

    public class Highestsaleprice
    {
        public string Amount { get; set; }
        public string CurrencyCode { get; set; }
        public string FormattedPrice { get; set; }
    }

    public class Lowestsaleprice
    {
        public string Amount { get; set; }
        public string CurrencyCode { get; set; }
        public string FormattedPrice { get; set; }
    }

    public class Itemlinks
    {
        public Itemlink[] ItemLink { get; set; }
    }

    public class Itemlink
    {
        public string Description { get; set; }
        public string URL { get; set; }
    }

    public class Smallimage
    {
        public string URL { get; set; }
        public Height Height { get; set; }
        public Width Width { get; set; }
    }

    public class Height
    {
        public string Units { get; set; }
        public string text { get; set; }
    }

    public class Width
    {
        public string Units { get; set; }
        public string text { get; set; }
    }

    public class Mediumimage
    {
        public string URL { get; set; }
        public Height1 Height { get; set; }
        public Width1 Width { get; set; }
    }

    public class Height1
    {
        public string Units { get; set; }
        public string text { get; set; }
    }

    public class Width1
    {
        public string Units { get; set; }
        public string text { get; set; }
    }

    public class Largeimage
    {
        public string URL { get; set; }
        public Height2 Height { get; set; }
        public Width2 Width { get; set; }
    }

    public class Height2
    {
        public string Units { get; set; }
        public string text { get; set; }
    }

    public class Width2
    {
        public string Units { get; set; }
        public string text { get; set; }
    }

    public class Imagesets
    {
        public object ImageSet { get; set; }
    }

    public class Itemattributes
    {
        public string Binding { get; set; }
        public string Brand { get; set; }
        public string Color { get; set; }
        public string Model { get; set; }
        public string Manufacturer { get; set; }
        public string ProductGroup { get; set; }
        public string Title { get; set; }
        public ListPrice ListPrice { get; set; }
    }

    public class ListPrice
    {
        public string Amount { get; set; }
        public string CurrencyCode { get; set; }
        public string FormattedPrice { get; set; }
    }

    public class OfferSummary
    {
        public Lowestnewprice LowestNewPrice { get; set; }
        public Lowestusedprice LowestUsedPrice { get; set; }
        public string TotalNew { get; set; }
        public string TotalUsed { get; set; }
        public string TotalCollectible { get; set; }
        public string TotalRefurbished { get; set; }
        public Lowestrefurbishedprice LowestRefurbishedPrice { get; set; }
    }

    public class Lowestnewprice
    {
        public string Amount { get; set; }
        public string CurrencyCode { get; set; }
        public string FormattedPrice { get; set; }
    }

    public class Lowestusedprice
    {
        public string Amount { get; set; }
        public string CurrencyCode { get; set; }
        public string FormattedPrice { get; set; }
    }

    public class Lowestrefurbishedprice
    {
        public string Amount { get; set; }
        public string CurrencyCode { get; set; }
        public string FormattedPrice { get; set; }
    }

    public class Offers
    {
        public string TotalOffers { get; set; }
        public string TotalOfferPages { get; set; }
        public string MoreOffersUrl { get; set; }
        public Offer Offer { get; set; }
    }

    public class Offer
    {
        public Merchant Merchant { get; set; }
        public Offerattributes OfferAttributes { get; set; }
        public Offerlisting OfferListing { get; set; }
    }

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

    public class Offerattributes
    {
        public string Condition { get; set; }
    }

    public class Offerlisting
    {
        public string OfferListingId { get; set; }
        public string PricePerUnit { get; set; }
        public Price Price { get; set; }
        public string Availability { get; set; }
        public Availabilityattributes AvailabilityAttributes { get; set; }
        public string IsEligibleForSuperSaverShipping { get; set; }
        public string IsEligibleForPrime { get; set; }
        public Saleprice SalePrice { get; set; }
        public Amountsaved AmountSaved { get; set; }
        public string PercentageSaved { get; set; }
    }

    public class Price
    {
        public string Amount { get; set; }
        public string CurrencyCode { get; set; }
        public string FormattedPrice { get; set; }
    }

    public class Availabilityattributes
    {
        public string AvailabilityType { get; set; }
        public string MinimumHours { get; set; }
        public string MaximumHours { get; set; }
    }

    public class Saleprice
    {
        public string Amount { get; set; }
        public string CurrencyCode { get; set; }
        public string FormattedPrice { get; set; }
    }

    public class Amountsaved
    {
        public string Amount { get; set; }
        public string CurrencyCode { get; set; }
        public string FormattedPrice { get; set; }
    }

Business class

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Xml;
using System.Xml.Linq;
using ApplicationDataServices.SBEntityBox;

namespace ApplicationManagementLayer.Affiliate
{
    public class Amazon
    {
        private int ItemPage { get; set; }
        public int TotalNumberOfItem { get; set; }

public Amazon()
{
    ItemPage = 1;
    TotalNumberOfItem = 0;
}

 
string XMLURL = string.Empty;



 public async Task<AmazonRootobject> getProductsByKeywords(string q, Dictionary<string, string> CategoryNames, int ItemPage, string categorynamebyid)
{
    try
    {
        AWSSignedRequestHelper helper = new AWSSignedRequestHelper("para1", "para2", "webservices.amazon.in", "para3");
        IDictionary<string, string> r1 = new Dictionary<string, String>();
        r1["Service"] = "AWSECommerceService";

        r1["Operation"] = "ItemSearch";


        if (CategoryNames != null && CategoryNames.Any() && CategoryNames.Where(o => o.Key.Equals("AmazonCategoryName")).Any())
            r1["SearchIndex"] = CategoryNames.Where(o => o.Key.Equals("AmazonCategoryName")).First().Value;
        else
            r1["SearchIndex"] = "All";

        if (!r1["SearchIndex"].Equals("All") && CategoryNames != null && CategoryNames.Any() && CategoryNames.Where(o => o.Key.Equals("AmazonReferenceCategoryId")).Any())
            r1["BrowseNode"] = CategoryNames.Where(o => o.Key.Equals("AmazonReferenceCategoryId")).First().Value;

        if (!string.IsNullOrEmpty(q))
            r1["Keywords"] = q;
        else if (!string.IsNullOrEmpty(categorynamebyid))
            r1["Keywords"] = categorynamebyid;
        else if (CategoryNames != null && CategoryNames.Any() && CategoryNames.Where(o => o.Key.Equals("AmazonCategoryName")).Any())
            r1["Keywords"] = CategoryNames.Where(o => o.Key.Equals("AmazonCategoryName")).First().Value;
        else
            return null;

        r1["ResponseGroup"] = "Images,ItemAttributes,OfferFull,Offers,Variations";
        r1["Version"] = "2013-08-01";
        r1["ItemPage"] = ItemPage.ToString();
        //r1["Sort"] = "salesrank";

        string strRequestUrl = helper.Sign(r1);

        string output = null;
        using (System.Net.Http.HttpClient wc = new System.Net.Http.HttpClient())
        {
            var request = new System.Net.Http.HttpRequestMessage()
            {
                RequestUri = new Uri(strRequestUrl),
                Method = System.Net.Http.HttpMethod.Get,
            };

            /*var task =*/
            await wc.SendAsync(request)
                .ContinueWith((taskwithmsg) =>
                {
                    var response = taskwithmsg.Result;

                    var jsonTask = response.Content.ReadAsStringAsync();
                    jsonTask.Wait();
                    output = jsonTask.Result;
                });
            //task.Wait();

        }

        XmlDocument doc = new XmlDocument();
        doc.LoadXml(output);
        string outputJson = XmlToJSON(doc);

        var pro = new System.Web.Script.Serialization.JavaScriptSerializer().Deserialize<AmazonRootobject>(outputJson);
        TotalNumberOfItem = !string.IsNullOrEmpty(pro.ItemSearchResponse.Items.TotalResults) ? Convert.ToInt32(pro.ItemSearchResponse.Items.TotalResults) : 0;
        return pro;
        //return "";
    }
    catch
    {
        return null;
    }
}

https://stackoverflow.com/documentation/amazon-web-services/drafts/87373#
 


    }
}