Latest revision as of 13:50, 21 July 2020

Knowledge Base

How to Display Random Images Using ASP

Article ID: 247745

Article Last Modified on 11/21/2006

APPLIES TO

Microsoft Internet Information Services 5.0

This article was previously published under Q247745

SUMMARY

This article describes the process for returning a random image from a folder in your Web site using Microsoft Active Server Pages (ASP) and the Scripting.FileSystemObject.

MORE INFORMATION

Microsoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements.

Random Images from ASP

Use the following steps to create an include file for use with ASP containing the RandomImage() function. The RandomImage() function randomly returns the name of an image based on the contents in a folder, which is passed by name to the function, or based on the name of a default image if no images are found in the folder.

Create a folder named "Images" in your Web site's root folder.Copy a few .gif or .jpg images into the Images folder.Save the following ASP page as "RandomTest.asp" in your Web site's root folder:

<% @Language="VBScript" %>
<% Option Explicit %>
<html>
<head>
<!--#include virtual="/includes/RandomImage.inc"-->
</head>
<body>
<div align="center"><center>
<table border="1">
  <tr>
    <td bgcolor="#ffffff">
      <img src="<%=RandomImage("/images/","/images/default.gif")%>">
    </td>
  </tr>
</table>
</center></div>
</body>
</html>

Note: The call to the RandomImage() function passes the name of the default image as /Images/Default.gif. You will need to change that to a valid image name and path when you want the function to a return a default image when a folder contains no images.

Create a folder named "Includes" in your Web site's root directory.Save the following ASP code in the Includes folder as RandomImage.inc:

<%
  Function RandomImage(strPath,strDefault)
    On Error Resume Next
    Randomize Timer

    ' declare all variables
    Dim objFSO, objFolder, objFiles, objFile
    Dim strFiles, strImages, strPhysical, strFile

    ' this constant has the names of valid image file name
    ' extensions and can be modified for more image types
    Const strValid = ".gif.jpg.png"

    ' make sure we have a trailing slash in the path
    If Right(strPath,1) <> Chr(47) Then strPath = strPath & Chr(47)
    ' get the physical path of the folder
    strPhysical = Server.MapPath(strPath)
    ' get a File System Object
    Set objFSO = Server.CreateObject("Scripting.FileSystemObject")
    ' create a folder object
    Set objFolder = objFSO.GetFolder(strPhysical)
    ' get the files collection
    Set objFiles = objFolder.Files

    ' enumerate the files collection looking for images
    For Each objFile in objFiles
      strFile = LCase(objFile.Name)
      If Instr(strValid,Right(strFile,4)) Then
        ' add vaild images to a string of image names
        strFiles = strFiles & strFile & vbTab
      End If
    Next

    ' split the image names into an array
    strImages = Split(strFiles,vbTab)
    
    ' if we have an array...
    If UBound(strImages) > 1 Then
      ' get a random name
      RandomImage = strPath & strImages(Int(Rnd(1)*UBound(strImages)))
    Else
      ' otherwise return the default
      RandomImage = strDefault
    End If

  End Function
%>