im包含db.php在index.php文件的顶部..但是在包含它之后，我的css和bootstrap无法正常工作
这是我的php文件，其中包括。 includes在include内是一个文件夹，并且db.php文件在其中]
<?php
include("includes/db.php");
?>
2。这是html代码
<!DOCTYPE html>
<html>
<head>
<title>E-COMMERCE</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
<link rel="stylesheet" type="text/css" href="style/style.css">
</head>
<body>
<div id="top">
<div class="container">
<div class="col-md-6 offer">
<a href="#" class="btn btn-success btn-sm">welcome guest</a>
<a href="#">shopping card total price:inr 100,total item 2 </a>
</div>
<div class="col-md-6">
<ul class="menu">
<li><a href="registration.php">register</a></li>
<li><a href="customer/my_account.php">my account</a></li>
<li><a href="#">go to cart</a></li>
<li><a href="#">login</a></li>
</ul>
</div>
</div>
</div>
3。这是动态滑块的php代码
<?php
$get_table="select * from slider LIMIT 0,1";
$run_slider=mysqli_query($con,$get_table);
while($row=mysqli_fetch_array($run_slider)){
$slider_name=$row['slider_name'];
$slider_image=$row['slider-image'];
echo "<div class='item active'>
<img src='admin_area/slider/$slider_image' alt='$slider_name'>
</div>";
}
?>
<?php
$get_table="select * from slider LIMIT 1,3";
$run_slider=mysqli_query($con,$get_table);
while($row=mysqli_fetch_array($run_slider)) {
$slider_name=$row['slider_name'];
$slider_image=$row['slider-image'];
echo "<div class='item'>
<img src='admin_area/slider/$slider_image' alt='$slider_name' >
</div>";
}
?>
我猜您的db.php文件正在echo开头<html>上方的某些文本中，这会损坏您的HTML。
[尝试在网络浏览器中查看页面的源，然后将其粘贴到HTML验证器中，它应向您显示问题所在：https://validator.w3.org/#validate_by_input+with_options