<%@ WebHandler Language="C#" Class="FileUploadHandler" %>

using System;
using System.IO;
using System.Net;
using System.Web;
using System.Web.Script.Serialization;

public class FileUploadHandler : IHttpHandler
{
    public void ProcessRequest(HttpContext context)
    {
        context.Response.ContentType = "text/plain";
        string unique_id = "", folder_name = "";
        if (context.Request.Form["unique_id"].ToString() != null && !String.IsNullOrEmpty(context.Request.Form["unique_id"].ToString()))
        {
            unique_id = context.Request.Form["unique_id"].ToString();
            folder_name = context.Request.Form["folder_name"].ToString();
            UploadFile(context, unique_id, folder_name);//to identify user id   and control id
        }
        else
        {
            context.Response.Write("Invalid Call");
        }
    }

    #region UploadFile
    public void UploadFile(HttpContext context, string unique_id, string folder_name)
    {
        string base_dir = AppDomain.CurrentDomain.BaseDirectory;//Base Directory
        CreateDirectoryIfNotExists(HttpContext.Current.Application["BASE_DIR"] + "\\TempFile\\" + folder_name + "\\");
        string str_image = "";

        HttpPostedFile file = context.Request.Files["file"];
        string fileName = file.FileName;
        string fileExtension = Path.GetExtension(fileName);

        if (!string.IsNullOrEmpty(fileName))
        {
            fileExtension = Path.GetExtension(fileName);
            //here @ key add to identify unique key porsion from file name use in delete of this catagory file
            str_image = unique_id + fileExtension;
            string filePath = Handle.ToString(HttpContext.Current.Application["BASE_DIR"] + "\\TempFile\\" + folder_name + "\\" + str_image);

            file.SaveAs(HttpContext.Current.Application["BASE_DIR"] + "\\TempFile\\" + folder_name + "\\" + str_image);
        }

        //pass image name for database update logic
        context.Response.Write(str_image);
    }
    #endregion

    #region CreateDirectoryIfNotExists
    private Boolean CreateDirectoryIfNotExists(string NewDirectory)
    {
        try
        {
            // Checking the existance of directory
            if (!Directory.Exists(NewDirectory))
            {
                //If No any such directory then creates the new one
                Directory.CreateDirectory(NewDirectory);
                return true;
            }
            else
            {

                return true;
            }
        }
        catch (IOException _err)
        {
            return false;
        }
    }
    #endregion

    public bool IsReusable
    {
        get
        {
            return false;
        }
    }
}