How to automatically scroll and display images on the page using PHP-PHP Tutorial-php.cn

How to automatically scroll and display images on the page using PHP

墨辰丷

Release： 2023-03-31 19:44:01

Original

3948 people have browsed it

This article mainly introduces the method of automatic scrolling display of pictures in PHP. It involves the skills of operating picture special effects in PHP. It has certain reference value. Friends in need can refer to it.

The examples in this article are described PHP implements a method to automatically scroll and display images. The details are as follows:

Specify a picture directory, and the program will automatically scroll and display each picture on the page. How to use:

1. Create a slideshow image folder.
2. Delete the slideshow in the image folder.
3. After encoding the following code, paste it in a text file and name it "index.php"
4. Upload the file to a directory
5. Replace lines 6 and 8 with your corresponding ones set up.
6. Run (using the URL set in step 4)

The code is as follows:

<?
/*
    PHP image slideshow - auto version - PHP5
*/
// set the absolute path to the directory containing the images
define (&#39;IMGDIR&#39;, &#39;/home/devel/public_html/domain.com/public/images/slideshow/&#39;);
// same but for www
define (&#39;WEBIMGDIR&#39;, &#39;/images/slideshow/&#39;);
// set session name for slideshow "cookie"
define (&#39;SS_SESSNAME&#39;, &#39;slideshow_sess&#39;);
// global error variable
$err = &#39;&#39;;
// start img session
session_name(SS_SESSNAME);
session_start();
// init slideshow class
$ss = new slideshow($err);
if (($err = $ss->init()) != &#39;&#39;)
{
    header(&#39;HTTP/1.1 500 Internal Server Error&#39;);
    echo $err;
    exit();
}
// get image files from directory
$ss->get_images();
// set variables, done.
list($curr, $caption, $first, $prev, $next, $last) = $ss->run();
/*
    slideshow class, can be used stand-alone
*/
class slideshow
{
    private $files_arr = NULL;
    private $err = NULL;
    public function __construct(&$err)
    {
        $this->files_arr = array();
        $this->err = $err;
    }
    public function init()
    {
        // run actions only if img array session var is empty
        // check if image directory exists
        if (!$this->dir_exists())
        {
            return &#39;Error retrieving images, missing directory&#39;;
        }
        return &#39;&#39;;
    }
    public function get_images()
    {
        // run actions only if img array session var is empty
        if (isset($_SESSION[&#39;imgarr&#39;]))
        {
            $this->files_arr = $_SESSION[&#39;imgarr&#39;];
        }
        else
        {
            if ($dh = opendir(IMGDIR))
            {
                while (false !== ($file = readdir($dh)))
                {
                    if (preg_match(&#39;/^.*\.(jpg|jpeg|gif|png)$/i&#39;, $file))
                    {
                        $this->files_arr[] = $file;
                    }
                }
                closedir($dh);
            }
            $_SESSION[&#39;imgarr&#39;] = $this->files_arr;
        }
    }
    public function run()
    {
        $curr = 1;
        $last = count($this->files_arr);
        if (isset($_GET[&#39;img&#39;]))
        {
            if (preg_match(&#39;/^[0-9]+$/&#39;, $_GET[&#39;img&#39;])) $curr = (int)  $_GET[&#39;img&#39;];
            if ($curr <= 0 || $curr > $last) $curr = 1;
        }
        if ($curr <= 1)
        {
            $prev = $curr;
            $next = $curr + 1;
        }
        else if ($curr >= $last)
        {
            $prev = $last - 1;
            $next = $last;
        }
        else
        {
            $prev = $curr - 1;
            $next = $curr + 1;
        }
        // line below sets the caption name...
        $caption = str_replace(&#39;-&#39;, &#39; &#39;, $this->files_arr[$curr - 1]);
        $caption = str_replace(&#39;_&#39;, &#39; &#39;, $caption);
        $caption = preg_replace(&#39;/\.(jpe?g|gif|png)$/i&#39;, &#39;&#39;, $caption);
        $caption = ucfirst($caption);
        return array($this->files_arr[$curr - 1], $caption, 1, $prev, $next, $last);
    }
    private function dir_exists()
    {
        return file_exists(IMGDIR);
    }
}
?>

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<!DOCTYPE html >
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>Slideshow</title>
    <style type="text/css">
    body{margin: 0;padding: 0;font: 100% Verdana, Arial, Helvetica, sans-serif;font-size: 14px;}
    p#gallery{border: 1px #ccc solid;width: 600px;margin: 40px auto;text-align: center;}
    p#gallery img{margin: 20px;border: 2px #004694 solid;}
    p#gallery p{color: #004694;}
    p#gallery p.pn{padding: 10px;margin: 0 5px;border-top: 1px #ccc solid;}
    a{color:#333;}
    a:hover{color:#cc0000;}
    a.sp{padding-right: 40px;}
    </style>
</head>
<body>
    <p id="gallery">
        <img src="<?=WEBIMGDIR;?><?=$curr;?>" alt="" />
        <p><?=$caption;?></p>
        <p class="pn">
            <a href="?img=<?=$first;?>">First</a> | <a href="?img=<?=$prev;?>" class="sp">Previous</a><a href="?img=<?=$next;?>">Next</a> | <a href="?img=<?=$last;?>">Last</a>
        </p>
    </p>
</body>
</html>

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