How to use ASP. NET anti-leech Protection

Anti-leeching technology can effectively solve the problems of low website traffic but high pressure. Now we will take the .jpg file as an example to illustrate how to implement anti-leech Technology in Asp.net.

Create an Asp.net website and add two image files: right.jpg, error.jpg, and right.jpg, which are the images shown on the current site, and error.jpg, which are the error images when other websites access the website.

Default. aspx place the following code:

<Asp: Image id = "image1" runat = "server" Height = "179px" imageurl = "~ /Right.jpg "width =" 197px "/>

Create a handler. CS class with the following code:

Using system;
Using system. Web;

Public class handler: ihttphandler {

Public void processrequest (httpcontext context ){

Context. response. expires = 0;
Context. response. Clear ();
Context. response. contenttype = "image/jpg ";

If (context. Request. urlreferrer. Host = "localhost ")
{

Context. response. writefile (context. Request. physicalpath );
Context. response. End ();
}
Else
{
Context. response. writefile (context. Request. physicalapplicationpath + "error.jpg ");
Context. response. End ();
}
}

Public bool isreusable {
Get {
Return true;
}
}

}

Add the following code to the Web. config node:

<Add verb = "*" Path = "*. jpg" type = "handler"/>

Debug the program, and the picture will be displayed as normal.

Give "localhost" in the Code if (context. Request. urlreferrer. Host = "localhost") to another host, and the program will display error.jpg

In this way, we have achieved what we call the image anti-leech technology.

Now, how can this effect be displayed in IIS.

Choose website> right-click Properties> virtual directory> Configuration> ing> Add

Press add to select an executable file:

C: \ windows \ Microsoft. NET \ framework \ v2.0.50727 \ aspnet_isapi.dll

In this way, your website also implements anti-leech technology.