Development log: Anti-leech application based on the ihttphandler interface function

Create the urlhandler. CS file,CodeAs follows:

 

Using System. Web;

Namespace Baselibrary {
Public   Class Urlhandler: ihttphandler {
// Indicates whether the httphandler implementation class needs to be cached.
Public   Bool Isreusable {
Get { Return   True ;}
}

PublicUrlhandler (){
}

Public   Void Processrequest (httpcontext context ){
String Filename = Context. server. mappath (context. Request. filepath );
If (Context. Request. urlreferrer ! =   Null ){
If (Context. Request. urlreferrer. Host =   Null ){
Context. response. contenttype =   " Image/JPEG " ;
Context. response. writefile ( " ~ /No.jpg " ); // Replaced Image
} Else {
If (Context. Request. urlreferrer. Host. indexof ( " Vote.yeshj.com " ) >   - 1 ) // Here is your domain name, such as www.maticsoft.com
{
Context. response. contenttype =   " Image/JPEG " ;
Context. response. writefile (filename );
} Else {
Context. response. contenttype =   " Image/JPEG " ;
Context. response. writefile ( " ~ /No.jpg " );
}
}
} Else {
Context. response. contenttype =   " Image/JPEG " ;
Context. response. writefile (filename );
}
}
}
}

 

Add the following code to the

 

< Httphandlers >
< Add Verb = "*" Path = "*. Jpg" Type = "Baselibrary. urlhandler, baselibrary" />
</ Httphandlers >

 

Configure IIS for the website
In the site's main directory =, configure =, and ISAPI
An extension name is 2.16.jpg ";
Extension of the executable file address: "C: \ WINDOWS \ Microsoft. NET \ framework \ v2.0.50727 \ aspnet_isapi.dll"

In this example, when the external display chain is connected to this week's image, No. jpg will be displayed.

 

Thoughts:

In this case, I only used the .jpg anti-leech feature. How do I implement anti-leech protection in multiple image formats?