Reuse image handler using session in asp.net

Question

3.00/5 (1 vote)

See more:

Hi guys,

I was working on Image Handler in asp.net,

where i have stored images in sql db, n fetching the imgs from db,

to view those imgs i m using ImgHndlr.ashx using Sessions

So, i want to reuse image handler instead of creating img hndlr for every img...

MY CODE:

Session["viewImg"] = dt.Rows[0]["EmpPicture"];
imgEmp.ImageUrl = "~/EmpImgHndlr.ashx";
Session["viewImg"] = dt.Rows[0]["IqamaPicture"];
imgI.ImageUrl = "~/EmpImgHndlr.ashx";
Session["viewImg"] = dt.Rows[0]["License"];
imgL.ImageUrl = "~/EmpImgHndlr.ashx";
Session["viewImg"] = dt.Rows[0]["Pp1"];
imgP1.ImageUrl = "~/EmpImgHndlr.ashx";
Session["viewImg"] = dt.Rows[0]["Pp2"];
imgP2.ImageUrl = "~/EmpImgHndlr.ashx";

ImgHndlr.ashx CODE:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
using System.Globalization;
using System.Threading;
using System.IO;
using System.Drawing;
using System.Web.SessionState;
using DataAccessLayer;

namespace RASAKTMS
{
    /// <summary>
    /// Summary description for EmpImgHndlr
    /// </summary>
    public class EmpImgHndlr : IHttpHandler, System.Web.SessionState.IRequiresSessionState
    {

        public void ProcessRequest(HttpContext context)
        {
            if (context.Session["viewImg"] != null)
            {
                Byte[] imgdata = (Byte[])(context.Session["viewImg"]);
                context.Response.BinaryWrite(imgdata);
                context.Response.End();
            }
        }

       

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

Please guys, help me to sort out this issue.

or

is it possible or not...

THANKS

Posted 1-Mar-14 7:42am

abdul subhan mohammed

Updated 1-Mar-14 20:04pm

v2

Add a Solution

2 solutions

Solution 1

You should pass to the handler the "type" of image you want the handler to render back. In your code you could do this:

C#

Session["EmpPicture"] = dt.Rows[0]["EmpPicture"];
imgEmp.ImageUrl = "~/EmpImgHndlr.ashx?type=EmpPicture";
Session["IqamaPicture"] = dt.Rows[0]["IqamaPicture"];
imgI.ImageUrl = "~/EmpImgHndlr.ashx?type=IqamaPicture";
Session["License"] = dt.Rows[0]["License"];
imgL.ImageUrl = "~/EmpImgHndlr.ashx?type=License";
Session["Pp1"] = dt.Rows[0]["Pp1"];
imgP1.ImageUrl = "~/EmpImgHndlr.ashx?type=Pp1";
Session["Pp2"] = dt.Rows[0]["Pp2"];
imgP2.ImageUrl = "~/EmpImgHndlr.ashx?type=Pp2";

Then in your handler....

C#

public void ProcessRequest(HttpContext context)
{
    string imgType = context.Request["type"];
    if (!string.IsNullOrEmpty(imgType) && context.Session[imgType] != null)
    {
        Byte[] imgdata = (Byte[])(context.Session[imgType]);
        context.Response.BinaryWrite(imgdata);
        //context.Response.End();
    }
}

Posted 1-Mar-14 13:50pm

Marc Gabrie

Comments

abdul subhan mohammed 2-Mar-14 1:30am

In this line "imgEmp.ImageUrl = "~/EmpImgHndlr.ashx?type=EmpPicture";"
what is 'EmpPicture'?, is a session? or what?

Marc Gabrie 3-Mar-14 10:26am

It's the name you assigned to the image which you stored in the Session that you want to display. That is the param that the Handler will take to get the image from the Session object and render it back to the client.

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Krunal Rohit · Accepted Answer · 2014-03-01T21:49:00

Okay, it seems that you've used DataTable and you're getting Image URL from that.
Let me show you one example, where I have created one custom Listview, in which I'm retrieving images from the database using Handler.
.aspx :

ASP.NET

<asp:listview id="ListView1" runat="server" datakeynames="ImgID" xmlns:asp="#unknown">
                onitemediting="ListView1_ItemEditing"
                onitemdeleting="ListView1_ItemDeleting" 
                onitemupdating="ListView1_ItemUpdating" 
                onitemcommand="ListView1_ItemCommand">
                <itemtemplate>
                    <table style="width:auto">
                        <tr>
                            <td>
                                <asp:checkbox id="CheckBox1" runat="server" />
                            </td>
                            <td>
                                <asp:image id="Image1" runat="server" imageurl="<%# "ImageHandler.ashx?ImageId=" + Eval("ImgID") %>" cssclass="Image" />
                            </td>
                            <td>
                                 <asp:label id="NameLabel" runat="server" text="<%# Eval("Name") %>" style="color:#FFF; font-family:Segoe UI Semibold;" /> <br />
                                 <asp:label id="CreatorLabel" runat="server" text="<%# Eval("Creator") %>" style="color:#ECECEC; font-family:Segoe UI; font-size:small;" /> <br />
                                 <asp:linkbutton id="EditBtn" runat="server" text="Edit" commandname="Edit" cssclass="Btn" />
                                 <asp:linkbutton id="DeleteBtn" runat="server" text="Delete" commandname="Delete" cssclass="Btn" />
                            </td>
                        </tr>
                    </table>
                </itemtemplate>

            </asp:listview>

.aspx.cs :

public void BindGrid()
{
    con.Open();

    SqlCommand cmd = new SqlCommand("SELECT * FROM GamesList", con);
    SqlDataAdapter da = new SqlDataAdapter(cmd);
    DataTable dt = new DataTable();
    da.Fill(dt);

    ListView1.DataSource = dt;
    ListView1.DataBind();

    con.Close();
}

Handler :

C#

public class ImageHandler : IHttpHandler
   {
       public void ProcessRequest(HttpContext context)
       {
           SqlConnection con = new SqlConnection(@"Data Source=rohit\sqlexpress;Initial Catalog=Games;Integrated Security=True");

           try
           {
               con.Open();

               string ImageId = context.Request.QueryString["ImageId"];

               SqlCommand cmd = new SqlCommand("select AlbumArt from GamesList where ImgID = " + ImageId, con);

               cmd.Connection = con;
               SqlDataAdapter da = new SqlDataAdapter(cmd);
               DataTable dt = new DataTable();
               da.Fill(dt);

               foreach (DataRow dr in dt.Rows)
               {
                   byte[] photu = dr[0] as byte[];
                   context.Response.BinaryWrite(photu);
                   context.Response.End();
               }
           }

           catch (Exception ex)
           {
               ex.ToString();
               context.Response.Write(ex.ToString());
           }
           finally
           {
               con.Close();
           }
       }

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

Go with this example, (in my opinion)you don't have use Session over here. Let me know If I lost you somewhere.

-KR