Original article: http://blog.csdn.net/ChengKing/archive/2007/01/05/1475121.aspx
I sorted it out.
(1 ). httpHandlers can process requests for a specific file type. for example, in machine. by default, a majority of Handlers are processed in the config file: 2 using System. Data;
3 using System. Configuration;
4 using System. Web;
5 using System. Web. Security;
6 using System. Web. UI;
7 using System. Web. UI. WebControls;
8 using System. Web. UI. WebControls. WebParts;
9 using System. Web. UI. HtmlControls;
10
11 /// <summary>
12 // only admin users can directly view JPG and JPEG images.
13 /// </summary>
14 public class JpgHandler: IHttpHandler
15 {
16 public JpgHandler ()
17 {
18}
19 public void ProcessRequest (HttpContext hc)
20 {
21 string strFileName = hc. Server. MapPath (hc. Request. FilePath );
22 if (hc. User. IsInRole ("admin") // whether the current User is admin
23 {
24 hc. Response. ContentType = "image/JPEG ";
25 hc. Response. WriteFile (strFileName );
26}
27 else
28 {
29 hc. Response. ContentType = "image/JPEG ";
30 hc. Response. Write ("No Right ");
31}
32}
33 public bool IsReusable
34 {
35 get
36 {
37 return true;
38}
39}
40}
41 2. front page *. aspx code 1 <% @ Page Language = "C #" AutoEventWireup = "true" CodeFile = "Default. aspx. cs "Inherits =" _ Default "%>
2
3 <! DOCTYPE html PUBLIC "-// W3C // dtd xhtml 1.0 Transitional // EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
4
5 6 7 <title> HttpHandler validate users right </title>
8 9 <body>
10 <form id = "form1" runat = "server">
11 <div>
12 <asp: LinkButton ID = "LinkButton1" runat = "server" PostBackUrl = "a.jpeg" ToolTip = "Click me! "OnClick =" linkbutton#click "Width =" 149px "> A.jpeg </asp: LinkButton>
13 & nbsp;
14 </div>
15 </form>
16 </body>
17 18
3. register your own handler class configuration in the Web. Config file
1 <system. web>
2 3 <add verb = "*" path = "*. jpg, *. jpeg" type = "JpgHandler"/>
4 5 </system. web>
6
Here I will handle the program class JpgHandler. put cs under the App_Code folder. If this class is not placed under this class, it is set *. dll format, you should put this Assembly under the bin directory and configure it as follows:
1 <system. web>
2 3 <add verb = "*" path = "*. jpg, *. jpeg" type = "JpgHandler, YourDll"/>
4 5 </system. web>
6
(3) Download Sample Code
JpgHttpHandler.rar
