Php 更改产品页面上的正文背景

我正在为学校做一个项目。截止日期是明天。 当url为时，我想更改body标记并在产品页面上添加背景图像： php？category=nieuwBinnen&product=Belair+xch

我怎样才能做到这一点呢。我尝试了if-isset方法，但没有成功。 您可以在以下网站上查看该网站： 谢谢你的帮助

阿里

index.php

# geef de HTML code voor het openen van de pagina weer
htmlOpenen('Titel van de website');

# toon de header
toonHeader();

include 'menu.php';

?>

<?php 

if (isset($_GET['category']) && isset($_GET['product']) && isset($$_GET['category'])){  //display product if provided
    $category = $$_GET['category'];
    $product = $_GET['product'];
    $error_msg = 1;  //sets a basic error catcher in case product does not exist
    foreach ($category as $item) {
       if ($item['naam'] == $product) {
        echo '
        <section>
        <article class="product">
            <h2 class="item_name">'.$item['naam'].'</h2>

            <div id="image">'.$item['foto'].'</div>
            <p>'.$item['video'].'</p>
            <p>
                '.$item['fotos'].'
            </p>
        </article>
        ';

        echo '
            <article class="product simpleCart_shelfItem">
                <div id="slider3">
                    <ul class="pager">
                        <li><a href="" class="pagenum active" rel="0">Info</a></li>
                        <li><a href="" class="pagenum" rel="1">Reviews</a></li>
                        <li><a href="" class="pagenum" rel="2">Extra\'s</a></li>
                    </ul>                           
                    <div class="viewport">
                        <ul class="overview">
                            <li class="page"><p> '.$item['info'].' <hr />'.$item['prijs'].'Beschikbaarheid: '.$item['beschik'].' <br /><br />Aantal: <input type="text" value="1" class="item_Quantity"></p></li>
                            <li class="page"><p>'.$item['reviews'].'</p></li>
                            <li class="page"><p>'.$item['extras'].'</p></li>
                        </ul>
                    </div>
                </div>
                    <h2 class="item_name hide"> '.$item['naam'].' </h2>
                    <p class="hide">'.$item['thumb'].'</p>
                    <a class="item_add" href="javascript:;"> Plaats product <br />in je winkelmandje </a>                
            </article>
        ';

        echo '
            <article class="product box-shadow">
                <p>Met deze camera<br /> kun je zulke foto\'s<br /> maken</p>
                <div id="slider4">
                    <a class="buttons prev" href="#">left</a>
                        <div class="viewport">
                            <ul class="overview">
                                '.$item['upload'].'
                            </ul>
                        </div>
                    <a class="buttons next" href="#">right</a>
                </div>
                <!-- <form action="" method="post">
                    <input type="file" name="bestand"><br>
                    <input type="submit" name="submit" value="Upload foto">
                </form> -->

                <a class="upload" href="upload">Upload je<br /> eigen foto\'s</a>   
            </article>

            <article class="product">
                <p>filmrolletje</p>
            </article>
            </section>
        ';

        // echo $item['prijs']."<br/>";
        // echo $item['product']."<br/>";

        // echo $item['info']."<br/>";

        $error_msg = 0;
       }       
    }
 if ($error_msg){ //basic error message in case product does not exist
     echo 'The selected product no longer exists';
 } 
}          
else{  //displays all product if specific product not given
?>


<!-- producten carousel -->
<section class="carousel">
    <div class="banner"><img src="img/nieuw.jpg"></div>
    <div id="slider1">
        <a class="buttons prev" href="#">left</a>
        <div class="viewport">
            <ul class="overview">
                <?php 
                foreach($nieuwBinnen as $new) {
                    echo '
                        <li>
                            <a href="index.php?category=nieuwBinnen&product='.urlencode($new['naam']).'">
                            <p>'.$new['product'].'</p>
                            <h2>'.$new['naam'].'</h2>
                            </a>
                        </li>
                    ';
                }
                ?>
            </ul>
        </div>
        <a class="buttons next" href="#">right</a>
    </div>
</section>

<!-- producten carousel -->
<section class="carousel">
    <div class="banner"><img src="img/best.jpg"></div>
    <div id="slider1">
        <a class="buttons prev" href="#">left</a>
        <div class="viewport">
            <ul class="overview">
                <?php 
                foreach($bestSellers as $best) {
                    echo '
                        <li>
                            <a href="index.php?category=bestSellers&product='.urlencode($best['naam']).'">
                            <p>'.$best['product'].'</p>
                            <h2>'.$best['naam'].'</h2>
                            </a>
                        </li>
                    ';
                }
                ?>
            </ul>
        </div>
        <a class="buttons next" href="#">right</a>
    </div>
</section>
<?php
}

include 'footer.php';

?>

#geef de HTML代码打开了van de pagina weer
Htmlopenn（“Titel van de网站”）；
#香椿头
toonHeader（）；
包括“menu.php”；
?>
您可以使用JavaScript/JQuery动态设置它。
可以尝试以下方法：

$targetpage =  $_SERVER['SERVER_NAME'].'/index.php?category=nieuwBinnen&product=Belair+X'
   if (!$targetpage) {
          echo background 1;
    }else{
          echo background 2;
    }

然后在你的身体里

<body class="<?php echo $class ?>">

$ class='no-bgimage'; if (isset($_GET['product']) {
    $class='bgimage';
}

<body class="<?php echo $class ?>">

.bgimage {
background-image: url('page/to/your/image');
}