ASP.NET 2.0 HttpHandler实现对某种文件类型权限保护(示例代码下载)

学习整理了一下

(一). HttpHandlers能够处理对某种特定文件类型的请求.

例如, 在machine.config 文件中默认已经有大部分的系统处理Handlers：

<httpHandlers>

<add verb=”*” path=”*.aspx” type=”System..Web.UI.PageHandlerFactory” />

<add verb=”*” path=”*.ascx” type=”System..Web.HttpForbiddenHandler” />

<add verb=”*” path=”*.cs” type=” System..Web.HttpForbiddenHandler” />

<add verb=”*” path=”*.skin” type=” System..Web.HttpForbiddenHandler” />

<add verb=”*” path=”*.sitemap” type=” System..Web.HttpForbiddenHandler” />

…….

</httpHandlers>

创建一个HttpHandler也非常简单，下面将创建一个自定义的HttpHandler,

功能为验证访问: *.jpeg/jpg 图像文件权限. 通过这个示例演示其用法.

(二).代码如下

1. 处理程序HttpHandler文件 JpgHandler.cs 代码

1 using System;
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 /// 只有admin权限用户才能直接查看JPG和JPEG的图片
13 /// </summary>
14 public class JpgHandler:IHttpHandler
15 {
16 public JpgHandler()
17 {
18 }
19 public void ProcessRequest(HttpContexthc)
20 {
21 string strFileName = hc.Server.MapPath(hc.Request.FilePath);
22 if (hc.User.IsInRole( " admin " )) // 当前用户是否为admin权限
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( " NoRight " );
31 }
32 }
33 public bool IsReusable
34 {
35 get
36 {
37 return true ;
38 }
39 }
40 }
41

2.前台页面 *.aspx 代码

1 <% @PageLanguage = " C# " AutoEventWireup = " true " CodeFile = " Default.aspx.cs " Inherits = " _Default " %>
2
3 <! DOCTYPEhtmlPUBLIC " -//W3C//DTDXHTML1.0Transitional//EN " " http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd " >
4
5 < htmlxmlns = " http://www.w3.org/1999/xhtml " >
6 < headrunat = " server " >
7 < title > HttpHandlervalidateusersright </ title >
8 </ head >
9 < body >
10 < formid = " form1 " runat = " server " >
11 < div >
12 < asp:LinkButtonID = " LinkButton1 " runat = " server " PostBackUrl = " a.jpeg " ToolTip = " Clickme! " OnClick = " LinkButton1_Click " Width = " 149px " > A.jpeg </ asp:LinkButton >
13 & nbsp;
14 </ div >
15 </ form >
16 </ body >
17 </ html >
18

3.在Web.Config文件中注册自己的处理程序类配置

1 < system.web >
2 < httpHandlers >
3 < addverb = " * " path = " *.jpg,*.jpeg " type = " JpgHandler " />
4 </ httpHandlers >
5 </ system.web >
6

在这里我是将处理程序类 JpgHandler.cs 放到 App_Code文件夹下面，如果此类不是放在此类下面，而是以程序集*.dll格式的，则应该将此程序集放到bin目录下面，并且这样配置:

1 < system.web >
2 < httpHandlers >
3 < addverb = " * " path = " *.jpg,*.jpeg " type = " JpgHandler,YourDll " />
4 </ httpHandlers >
5 </ system.web >
6

(三). 示例代码下载

http://www.cnblogs.com/Files/ChengKing/JpgHttpHandler.rar