动态广告管理程序制作例子 -pc6资讯

您的位置：首页 → 精文荟萃 → 软件资讯 → 动态广告管理程序制作例子

动态广告管理程序制作例子 时间：2004/10/7 19:18:00来源：本站整理作者：蓝点我要评论(0): By Wayne Berry

This Issue

Many sites that are content specific depend on banner advertisement for revenue. Such is the case for 15

Seconds. A banner is displayed at the top of the page for every page viewed. Clients usually buy a set

number of banner impressions and these impressions are rotated amongst all the clients over a period of

time. In order to do this there must be a dynamic quality to the banners. In other words, the banner to

display is not determined until that page is requested.

With an Active Server page this is an easy task. Active Server Pages are dynamic and there are many

components that handle the task of banner rotation. A simple one comes free with the Internet Information

Server, and more complicated rotation schedules can be done with Site Server and other third party

components. This article is not about how to implement these components within your Active Server pages,

since this is a fairly easy task.

This article will describe how to implement a banner rotation scenario where the pages served are static,

i.e. .htm, and do not have the flexibility to call components. The task is to dynamically serve banners

and statically serve pages. This is the opposite of the scenario for banner rotation components, which

statically serve banners and dynamically serve pages.

One Trick

There is only one trick here and once you know it the rest is pretty straightforward. Internet Explorer

and Netscape allow you to refer to an Active Server Page within an image tag. Example 1 demonstrates the

HTML to be inserted in the static page.

Example 1 : HTML Banner Reference

< IMG SRC="http://www.myserver.com/ServeBanner.asp">

Once you have referred to a dynamic Active Server page with the static page, you need to build an Active

Server page to return an image, in this case a banner. Example 2 shows the code to use for servebanner.asp

which is called in Example 1.

Example 2 : ServeBanner.asp Source

<%

Response.Redirect("http://www.myserver.com/banner.gif")

%>

These two pages combined will allow you to display to the user a banner as if you referred directly to the

banner image instead of an Active Server page. In order to do banner rotation all you have to do is expand

Example 2 so different images come up every time ServeBanner.asp is called.

Adding the Element of Rotation.

With this technique the dynamic aspect of the banner rotation is controlled within the Active Server page

that the IMG tag is referring to. In order to randomly rotate the banners you will need to change

ServerBanner.asp to choose a different banner each time that it is called. Example 3 shows how to do this.

Example 3 : Rotating Banners

<%

Dim　　Array(2)

' Initialize the VBScript Random

' Number Generator

Randomize

Array(1)="http://www.myserver.com/banner1.gif"

Array(2)="http://www.myserver.com/banner2.gif"

upperbound=UBound(Array)

lowerbound=1　　

lRandom = Int((upperbound - lowerbound + 1) * Rnd + lowerbound)

Response.Redirect(Array(lRandom))

%>

Notice that you will have to initialize the array for as many banners as are available and you will have

to assign a banner to each element of the array.

An Extra Benefit

An obvious benefit to this type of banner rotation is that fact that you don't have to serve Active Server

pages in order to have rotating banners. If the only dynamic aspect of your Active Server page is to

rotate banners you will want to change it to use this banner rotation technique, since it will reduce the

stress on your server.

It might not be so obvious that the static pages no longer need to reside on your machine to rotate

banners. For example, you could give the HTML in Example 1 to a site that you were advertising on, and

when they serve there pages with your HTML your server will rotate the banners for their site. This allows

you control of what banners are presented to their readers. The site that was serving the static pages

could even be a different operating system, such as UNIX.

Clicking on the Banner

So far we have demonstrated how to rotate banners, but not how to activate those banners so that you can

click on the banner to go to another site. With one banner in the rotation this is a straightforward

process, you just point the anchor tag to the site which the banner represents. However when you have

multiple banners in the rotation it becomes more difficult. The problem is that a random banner is served

every time you request a page, however the anchor tag on that page does not change, since the page is

static.

To solve this problem the anchor tag needs to reference an Active Server page that can determine what

banner was being displayed so that it can redirect the browser to that page. Example 4 shows what the HTML

will look like to activate the banners in this banner rotation technique.

Example 4 : Activating the Banners

< A HREF=" http://www.myserver.com/BannerClick.asp">

< IMG SRC="http://www.myserver.com/ServeBanner.asp">

< /A>

BannerClick.asp now has the responsibility of redirecting to the correct location. However, currently

there is no way for BannerClick.asp to know which banner is being displayed to the user. In order to

determine this, ServeBanner.asp must tell the browser which banner it is going to display so that if the

user clicks through BannerClick.asp can ask the browser what banner was being shown. One way to do this is

to use cookies?. Example 5 shows how to modify ServeBanner.asp so that it sets a cookie every time a

banner is served.

Example 5 : Rotating Banners with Cookies

<%

Dim　　Array(2)

' Initialize the VBScript Random

' Number Generator

Randomize

Array(1)="http://www.myserver.com/banner1.gif"

Array(2)="http://www.myserver.com/banner2.gif"

upperbound=UBound(Array)

lowerbound=1　　

lRandom = Int((upperbound - lowerbound + 1) * Rnd + lowerbound)

Response.Cookies("BannerId")=lRandom

Response.Redirect(Array(lRandom))

%>

Once ServeBanner.asp is coded so that it issues a cookie for each request, and that cookie is the banner

identifier in the array, we can program ClickBanner.asp so that it reads the cookie and redirects to the

correct location. Example 6 shows how to implement ClickBanner.asp.

Example 6 : ClickBanner.asp

<%

Dim　　Array(2)

lBannerId = Request.Cookies("BannerId")

Array(1)="http://www.client1.com"

Array(2)= "http://www.client2.com"

Response.Redirect(Array(lBannerId))

%>

Notice that the array is used differently in ServeBanner.asp then it is used in ClickBanner.asp. In

ServeBanner.asp the array referenced banner graphics, in ClickBanner.asp the array references the location

to go to when the banners is clicked. Since the index in the array is used in both locations the array

must be populated so that for every index the banner image matches the location.

Handling Netscape

The Netscape browser has a bug in it that needs to be avoided when rotating banners using this technique.

If you do not specify the size of an image in HTML Netscape queries the image itself to determine the

size. This is a feature that both Netscape and Internet Explorer have. However, Netscape queries the first

response to the image call for the size. Using this technique the first response is a set of headers that

are suppose to redirect the browser to the real graphic. When Netscape queries the headers for the image

size it fails since the response its not an image. In order to avoid this problem you will need to specify

the banner image size in the HTML. Example 7 shows Example 4 rewritten to specify the image size.

Example 7 : Setting the Image Size

< A HREF=" http://www.myserver.com/BannerClick.asp">

< IMG WIDTH=468 HEIGHT=60 SRC="http://www.myserver.com/ServeBanner.asp">

< /A>

Because of this bug there is no way to serve banners that are of varying sizes, since the size is

specified in a static page which does not change with the banner that is served.

Beyond

The next step in creating your own banner rotation application is to put the banner arrays in a database

and to query the database every time a page is requested. This would allow you the flexibility to change

the banners using another set of Active Server pages which administers the database.

You could also implement a better rotation schema that would have a daily cap on the number of impressions

served and a maximum number of impressions to serve. You might also want to implement a default banner, so

that when the maximums are met there is something to rotate.

Another interesting addition would be the logging of the number of banners served and the number of click

throughs per banner. Then creating a set of Active Server pages to display the statistics in a variety of

forms.

However, before you go off and build yourself a database, and implement complicated banner rotation

algorithms you might want to consider buying a product that already does what you want. Banager

(http://www.banager.com) is an Active Server page application that is implemented using the techniques

discussed in this article. However, Banager has statistical pages, database logging and banner rotation

algorithms built in. In my opinion it is well worth the cost.

文章评论

查看所有0条评论>>