C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.Services;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;


namespace MultipleImageUploadDemo
{
    /// <summary>
    /// Summary description for SaveImageService
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    [System.ComponentModel.ToolboxItem(false)]
    // To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 
    [System.Web.Script.Services.ScriptService]
    public class SaveImageService : System.Web.Services.WebService
    {
        
        public SaveImageService()
        {
        }      

        [WebMethod]
        public void ProcessRequest(HttpContext context)
        {
            if (context.Request.Files.Count > 0)
            {
                HttpFileCollection files = context.Request.Files;
                foreach (string key in files)
                {
                    HttpPostedFile file = files[key];
                    string fileName = file.FileName;
                    fileName = context.Server.MapPath("~/Upload/" + fileName);
                    file.SaveAs(fileName);
                }
            }
            context.Response.ContentType = "image/JPEG";
            context.Response.Write("File(s) uploaded successfully!");
        }
       
    }  
}

System.Web.HttpContext cannot be serialized because it does not have a parameterless constructor.