Implement image anti-leech Protection Using ASP. NET

Use httpHandle to handle image file requests
Step 1: Create a class that inherits from IHttpHandler. The Code is as follows:

C # code

Using System;

Using System. Web;

 

Namespace CustomHandler {

Public class JpgHandler: IHttpHandler {

Public void ProcessRequest (HttpContext context ){

// Obtain the physical path of the file server

String FileName = context. Server. MapPath (context. Request. FilePath );

// If UrlReferrer is empty, a default anti-leeching image is displayed.

If (context. Request. UrlReferrer. Host = null ){

Context. Response. ContentType = "image/JPEG ";

Context. Response. WriteFile ("/error.jpg ");

} Else {

// If UrlReferrer does not contain the host domain name of your website, a default anti-leeching image is displayed.

If (context. Request. UrlReferrer. Host. IndexOf ("yourdomain.com")> 0 ){

Context. Response. ContentType = "image/JPEG ";

Context. Response. WriteFile (FileName );

} Else {

Context. Response. ContentType = "image/JPEG ";

Context. Response. WriteFile ("/error.jpg ");

}

}

}

 

Public bool IsReusable {

Get {return true ;}

}

}

}

 

Step 2: Compile to DLL
Csc/t: library CustomHandler. cs
Step 3: add the compiled DLL reference to the bin folder of the current site
Step 4: register the Handler in Web. Config

C # code

<System. web>

<HttpHandlers>

<Add path = "*. jpg ,*. jpeg ,*. gif ,*. png ,*. bmp "verb =" * "type =" CustomHandler. jpgHandler, CustomHandler "/>

</HttpHandlers>

</System. web>

 

// Verb indicates the method used to request this file. It can be post or get, and * indicates all access methods. CustomHandler. JpgHandler indicates the namespace and class name, And CustomHandler indicates the Set Name.