In this article I am going to show how we can show
images using asp.net handler.
In below example I am using a XML which have my Image
related data... You can pass your own height and width to show image...
<?xml version="1.0" encoding="utf-8" ?>
<IMAGES>
<IMAGE>
<id>1</id>
<ImgPath>1.jpg</ImgPath>
</IMAGE>
<IMAGE>
<id>2</id>
<ImgPath>2.jpg</ImgPath>
</IMAGE>
<IMAGE>
<id>3</id>
<ImgPath>3.jpg</ImgPath>
</IMAGE>
<IMAGE>
<id>4</id>
<ImgPath>4.jpg</ImgPath>
</IMAGE>
<IMAGE>
<id>5</id>
<ImgPath>5.jpg</ImgPath>
</IMAGE>
</IMAGES>
I am reading this XML on asp page and showing image in a
DataList.. my aspx is:
<%@ Page Language="C#"
AutoEventWireup="true"
CodeFile="Default.aspx.cs"
Inherits="_Default"
%>
<!DOCTYPE html PUBLIC
"-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Showing Image Using Handler</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<table cellpadding="4"
cellspacing="4"
width="40%"
align="center"
style="border: solid 1px Gray;">
<tr>
<td>
<asp:DataList ID="listImg"
runat="server"
RepeatColumns="4"
RepeatDirection="Horizontal"
CellPadding="4"
ForeColor="#333333">
<FooterStyle
BackColor="#5D7B9D"
Font-Bold="True"
ForeColor="White"
/>
<ItemTemplate>
<table>
<tr width="100%">
<td>
<img src="ImageHandler.ashx?width=100&Height=100&id=<%#
DataBinder.Eval(Container.DataItem, "Id") %>&ImagePath=<%#
DataBinder.Eval(Container.DataItem, "ImgPath") %>" />
</td>
</tr>
</table>
</ItemTemplate>
<AlternatingItemStyle
BackColor="White"
ForeColor="#284775"
/>
<ItemStyle
BackColor="#F7F6F3"
ForeColor="#333333"
/>
<SelectedItemStyle
BackColor="#E2DED6"
Font-Bold="True"
ForeColor="#333333"
/>
<HeaderStyle
BackColor="#5D7B9D"
Font-Bold="True"
ForeColor="White"
/>
</asp:DataList>
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
My aspx.cs is:
using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
public partial class _Default :
System.Web.UI.Page
{
protected void
Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
ReadData();
}
private void
ReadData()
{
DataSet ds = new DataSet();
ds.ReadXml(Server.MapPath("MyXMLFile.xml"));
listImg.DataSource = ds;
listImg.DataBind();
}
}
My Handler code is:
<%@ WebHandler Language="C#"
Class="ImageHandler"
%>
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web;
using System.Collections;
using System.IO;
using System.Web.SessionState;
using System.Drawing;
public class ImageHandler : IHttpHandler
{
private string XLen =
"40";
private string YLen =
"40";
public void
ProcessRequest(HttpContext context)
{
if (context.Request["id"]
!= null)
{
if (context.Request["Height"]
!= null)
{
XLen =
context.Request["Height"].ToString();
}
if (context.Request["width"]
!= null)
{
YLen =
context.Request["width"].ToString();
}
string id = context.Request["id"].ToString();
string ImgPath = context.Request["ImagePath"].ToString();
Hashtable ht;
ht = new Hashtable();
FileStream fInfo = new
FileStream(context.Server.MapPath(ImgPath), FileMode.Open);
byte[] bFile;
bFile =
GenerateThumbnail(fInfo, XLen, YLen);
ht.Add(id,
bFile);
fInfo.Close();
Byte[] arrImg = (byte[])ht[id];
context.Response.Clear();
context.Response.ContentType = "image/jpeg";
context.Response.BinaryWrite(arrImg);
context.Response.End();
}
}
private byte[]
GenerateThumbnail(Stream fStream, string xLen, string
yLen)
{
Image img = Image.FromStream(fStream);
Image thumbnailImage = img.GetThumbnailImage(int.Parse(xLen), int.Parse(yLen),
new Image.GetThumbnailImageAbort(ThumbnailCallback), IntPtr.Zero);
MemoryStream imageStream = new MemoryStream();
thumbnailImage.Save(imageStream, System.Drawing.Imaging.ImageFormat.Jpeg);
byte[] imageContent = new
Byte[imageStream.Length];
imageStream.Position = 0;
imageStream.Read(imageContent, 0, (int)imageStream.Length);
return imageContent;
}
public bool
ThumbnailCallback()
{
return true;
}
public bool
IsReusable
{
get
{
return false;
}
}
}
Below is my output:
Image 1.