PHP Random display directory under the picture _php Tutorial

Objective

Not so long ago, Twitter, @doublechou (talented woman, everyone follow, blog) is doing a theme (now she inove). She wanted to do a random change to the background image, written in JavaScript, the program flow should be: Create an array of images, a random selection of one of the values, create a style and write to the body tag.

But with JS do, there are the following shortcomings:

1. In case the browser disables JS, it will expire, and write code is to consider compatibility.

2. Maintenance is troublesome, the location of the picture is stored in the array.

So I proposed to use PHP processing, but I and her php are half a bucket of water, I can not think of how to do. Today, a high fortune, see a PHP random display directory of the source code, learn about, and share it.

Body

Take a look at the principle: Get a list of files of a certain type from a directory (usually jpg/gif/png on the web), select an image---Output code by random function.

The PHP code is as follows:

Copy to ClipboardWhat to refer to: [www.bkjia.com]$imglist = ";
Use the $img_folder variable to save the directory where the picture is located, must end with "/"
$img _folder = "images/tutorials/";

Mt_srand (Double) microtime () *1000);

Working with catalog classes
$imgs = Dir ($img _folder);

Check if there is a picture in the directory and generate a list
while ($file = $imgs->read ()) {
if (eregi ("gif", $file) | | eregi ("JPG", $file) | | eregi ("PNG", $file))
$imglist. = "$file";

} closedir ($imgs->handle);

Put all the items in the list in an array
$imglist = Explode ("", $imglist);
$no = sizeof ($imglist)-2;

Generates a random number between 0 and the number of pictures
$random = Mt_rand (0, $no);
$image = $imglist [$random];

Output results
Echo ';

If you want to change the page background through this function, you can change the last sentence to read:

Copy to ClipboardWhat to refer to: [www.bkjia.com]Echo '';

Replace the label with the entire program.
If you need to call this program multiple times, you can write a function that you want to rewrite as needed.

Summarize
The benefits of using PHP to output random images are:
1. Simple maintenance, only need to control the number of pictures in the directory.
2. Can customize the file type, as long as you need to change to random output a flash also line
3. You can customize the output, in other words, use it anywhere.
4. Function more powerful after rewriting into function

Transferred from: http://blog.imbolo.com/

http://www.bkjia.com/PHPjc/364413.html www.bkjia.com true http://www.bkjia.com/PHPjc/364413.html techarticle Foreword in the recent, Twitter, @doublechou (talented woman, everyone follow, blog) is doing the theme (now she temporarily used Inove). She wanted to do a random change of background image function, ...

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