Mega Code Archive
Implementing the IHttpHandler Interface
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File: App_Code\ImageHandler.cs
using System;
using System.Web;
using System.Data;
using System.Data.SqlClient;
using System.Web.Configuration;
namespace MyNamespace
{
public class ImageHandler : IHttpHandler
{
const string connectionStringName = "Images";
public void ProcessRequest(HttpContext context)
{
context.Response.Buffer = false;
string fileName = VirtualPathUtility.GetFileName(context.Request.Path);
string conString = WebConfigurationManager.ConnectionStrings [connectionStringName].ConnectionString;
SqlConnection con = new SqlConnection(conString);
SqlCommand cmd = new SqlCommand("SELECT Image FROM Images WHERE FileName=@FileName", con);
cmd.Parameters.AddWithValue("@fileName", fileName);
using (con)
{
con.Open();
SqlDataReader reader = cmd.ExecuteReader(CommandBehavior. SequentialAccess);
if (reader.Read())
{
int bufferSize = 8040;
byte[] chunk = new byte[bufferSize];
long retCount;
long startIndex = 0;
retCount = reader.GetBytes(0, startIndex, chunk, 0, bufferSize);
while (retCount == bufferSize)
{
context.Response.BinaryWrite(chunk);
startIndex += bufferSize;
retCount = reader.GetBytes(0, startIndex, chunk, 0, bufferSize);
}
byte[] actualChunk = new Byte[retCount - 1];
Buffer.BlockCopy(chunk, 0, actualChunk, 0, (int)retCount - 1);
context.Response.BinaryWrite(actualChunk);
}
}
}
public bool IsReusable
{
get { return true; }
}
}
}
Register the class in the web configuration file.
File: Web.Config
<configuration>
<connectionStrings>
<add name="Images"
connectionString="Data Source=.\SQLExpress;Integrated
Security=True;AttachDBFileName=|DataDirectory|ImagesDB.mdf;
User Instance=True"/>
</connectionStrings>
<system.web>
<httpHandlers>
<add path="*.gif" verb="*"
type="MyNamespace.ImageHandler" validate="false" />
<add path="*.jpeg" verb="*"
type="MyNamespace.ImageHandler" validate="false" />
<add path="*.jpg" verb="*"
type="MyNamespace.ImageHandler" validate="false" />
</httpHandlers>
</system.web>
</configuration>
Displaying images with the ImageHandler.
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void btnAdd_Click(object sender, EventArgs e)
{
if (upFile.HasFile)
{
srcImages.Insert();
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Image Upload</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Label
id="lblFile"
Text="Image File:"
AssociatedControlID="upFile"
Runat="server" />
<asp:FileUpload
id="upFile"
Runat="server" />
<asp:Button
id="btnAdd"
Text="Add Image"
OnClick="btnAdd_Click"
Runat="server" />
<hr />
<asp:GridView
id="grdImages"
DataSourceID="srcImages"
AutoGenerateColumns="false"
ShowHeader="false"
GridLines="None"
Runat="server">
<Columns>
<asp:ImageField
DataImageUrlField="FileName"
DataAlternateTextField="FileName" />
</Columns>
</asp:GridView>
<asp:SqlDataSource
id="srcImages"
ConnectionString="<%$ ConnectionStrings:Images %>"
SelectCommand="SELECT FileName FROM Images"
InsertCommand="INSERT Images (FileName,Image) VALUES (@FileName,@FileBytes)"
Runat="server">
<InsertParameters>
<asp:ControlParameter Name="FileName" ControlID="upFile" PropertyName="FileName" />
<asp:ControlParameter Name="FileBytes" ControlID="upFile" PropertyName="FileBytes" />
</InsertParameters>
</asp:SqlDataSource>
</div>
</form>
</body>
</html>
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