Introducation:

Explanation:

This Article is continuity of our Article Loading Images into SQL Server with C#. Here We will discuss about displaying a unique image for each user. This means every user will view an image he is allowed to or he have uploaded in his own profile

• For showing a static image in a gridview read Displaying Images in a GridView Column.
• For saving and displaying Users/Members Profile Images, Read the complete and detailed version at
  Save and Display Images using ASP .NET 2.0 Profile.

Article Requierments:

To make sure we undertsand the Article better, before we move next we need to make sure that we know about the following:

• GridView/DataGrid Control
• ASP .NET 2.0 ObjectDataSource
• ASP .NET 2.0 Membership Objects
• ASP .NET Generic Handlers

Now, when we made sure that we have the basic knowledge of what we will use in our article, we can go a head. Our Gridview look like this;

Instead of using BoundField we are using ItemTemplate to cerate our own customised Template. We are accessing our Images through a link which is pointing to our Handler (.ashx). So how does actually the Handler access images and present them to us? Handler process our Request and cerate a Proper Responce to it. This Responce Handling is actually what a Handler all about.

Here we will use an ObjectDataSource Object to access the current logged in user. Our ObjectDatasource Look like this:

TypeName="GetUsersData"
SelectMethod="GetUserName"
OldValuesParameterFormatString="original_{0}"/>

Here GetUsersData is our Class and GetUserName is a Static Method which brings the Current Logged-in User. To detrermin the Current Logged-in User you can use Membership and MembershipUser Objects.

We can create a Handler by right clicking on the Project > Add New Item > Select Generic Handler > Add . You can edit this newly created Handler. Now see how does our Handler look like;

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

using System;
using System.Web;
using System.IO;
using System.Configuration;

public class PicHandler : IHttpHandler
{

public void ProcessRequest(HttpContext context)
{
context.Response.ContentType = "image/jpeg";
context.Response.Cache.SetCacheability(HttpCacheability.Server);
context.Response.BufferOutput = false;
// Setup the PhotoID Parameter
Stream stream = null;
string userName = context.Request.QueryString["UserName"];
if (userName != null && userName != "")
{
stream = OurUsersData.GetUserPic(userName);
if (stream == null)
{
stream = OurUsersData.GetUserPic("defaultPicture");
}

}
// Write image stream to the response stream
const int buffersize = 1024 * 16;
byte[] buffer = new byte[buffersize];
int count = stream.Read(buffer, 0, buffersize);
while (count > 0)
{
context.Response.OutputStream.Write(buffer, 0, count);
count = stream.Read(buffer, 0, buffersize);
}
}

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

Where "ourUsersData" is Class defined in the "App-code" folder and "GetUserPic" is a satic function. The bold block is showing how to get an Image. If the user did not uploaded his picture the default image will be displayed instead.

How are we accessing our Database? If you are saving images to the User Profile in ASP .NET 2.0 then you need to create a method for accessing an image from the Profile System otherwise, if you are saving Images in your own Database then you can access the database by using ADO .NET 2.0. Make sure that the return type of your Method is a Stream.