我在php中创建了一个购物车，并实现了会话，但当用户单击服务器上详细信息页面上的添加到购物车按钮时，它不会重定向到cart-page.php，并且在localhost上运行良好。我认为头函数无法正常工作，请帮助我找出问题。
这是我的密码。
enter code here
<div id="central_content">
<?php
include("include/db.php");
include("include/functions.php");
error_reporting(E_ALL);
ini_set("display_errors", 1);
if(isset($_REQUEST['command']) && $_REQUEST['command']=='add' && $_REQUEST['productid']>0){
$pid=$_REQUEST['productid'];
addtocart($pid,1);
session_start();
if($_SESSION['login']=="loggedin")
{
header('location:cart-page.php');
}
else
{
?>
<script>
document.getElementById("logindiv").innerHTML="welcome";
</script>
<?php
header('location:login-page.php');
}
exit();}
?>
<script language="javascript">
function addtocart(pid){
document.form1.productid.value=pid;
document.form1.command.value='add';
document.form1.submit();
}
</script>
<body>
<form name="form1">
<input type="hidden" name="productid" />
<input type="hidden" name="command" />
</form>
<div align="center">
<h1 align="center">Henger2</h1>
<table border="0" cellpadding="2px" width="600px">
<?php
$result=mysql_query("SELECT * FROM `products` WHERE serial=1");
while($row=mysql_fetch_array($result)){
?>
<tr>
<td></td>
<td> <div class="product_item"> <div class="product_left"> <a href="<?=$row['picture']?>" class="simple_image" title=""><span class="product_zoom" style="display: none;"><img src="styles/Images/ico-zoom.png" alt="Zoom Picture" title="Zoom Picture" style="border:none;"/></span><img src="<?=$row['picture']?>" alt="Image 1" title=""/></a>
<div class="product_thumb_container">
</div>
</div>
</div>
</td>
<td>
<div class="product_right">
<div class="product_data">Product:</div>
<div class="product_data grey"><?=$row['name']?></div>
<div class="div_br"></div>
<div class="product_data">Product-Softwares:</div>
<div class="product_data grey"><?=$row['description']?></div>
<div class="div_br"></div>
<div class="product_data">Software-Format:</div>
<div class="product_data grey"><?=$row['desc']?></div>
<div class="div_br"></div>
<div class="product_data">Price:</div>
<div class="product_data grey">$<?=$row['price']?></div>
<div class="div_br"></div>
<input type="submit" value="Add to Cart" onclick="addtocart(<?=$row['serial']?>)" />
</td>
</tr>
<tr><td colspan="2"></td>
<?php } ?>
</table>
</div>
cart-page.php
<script language="javascript">
function del(pid){
if(confirm('Do you really mean to delete this item')){
document.form1.pid.value=pid;
document.form1.command.value='delete';
document.form1.submit();
}
}
function clear_cart(){
if(confirm('This will empty your shopping cart, continue?')){
document.form1.command.value='clear';
document.form1.submit();
}
}
function update_cart(){
document.form1.command.value='update';
document.form1.submit();
}
</script>
<?php
include("include/db.php");
include("include/functions.php");
if(isset($_REQUEST['command']) && $_REQUEST['command']=='delete' && $_REQUEST['pid']>0){
remove_product($_REQUEST['pid']);
}
else if(isset($_REQUEST['command']) && $_REQUEST['command']=='clear'){
unset($_SESSION['cart']);
}
else if(isset($_REQUEST['command']) && $_REQUEST['command']=='update'){
$max=count($_SESSION['cart']);
for($i=0;$i<$max;$i++){
$pid=$_SESSION['cart'][$i]['productid'];
$q=intval($_REQUEST['product'.$pid]);
if($q>0 && $q<=999){
$_SESSION['cart'][$i]['qty']=$q;
}
else{
$msg='Some proudcts not updated!, quantity must be a number between 1 and 999';
}
}
}
?>
<script language="javascript">
function del(pid){
if(confirm('Do you really mean to delete this item')){
document.form1.pid.value=pid;
document.form1.command.value='delete';
document.form1.submit();
}
}
function clear_cart(){
if(confirm('This will empty your shopping cart, continue?')){
document.form1.command.value='clear';
document.form1.submit();
}
}
function update_cart(){
document.form1.command.value='update';
document.form1.submit();
}
</script>
<form name="form1" method="post">
<input type="hidden" name="pid" />
<input type="hidden" name="command" />
<div style="margin:0px auto; width:600px;" >
<div style="padding-bottom:10px">
<h1 align="center">Your Shopping Cart</h1>
<input type="button" value="Continue Shopping" onclick="window.location='projects.php'" />
</div>
<div style="color:#F00"></div>
<table border="0" cellpadding="5px" cellspacing="1px" style="font-family:Verdana, Geneva, sans-serif; font-size:11px; background-color:#E1E1E1" width="100%">
<?php
if(is_array($_SESSION['cart'])){
echo '<tr bgcolor="#FFFFFF" style="font-weight:bold"><td>Serial</td><td>Name</td><td>Price</td><td>Qty</td><td>Amount</td><td>Options</td></tr>';
$max=count($_SESSION['cart']);
for($i=0;$i<$max;$i++){
$pid=$_SESSION['cart'][$i]['productid'];
$q=$_SESSION['cart'][$i]['qty'];
$pname=get_product_name($pid);
if($q==0) continue;
?>
<tr bgcolor="#FFFFFF"><td><?=$i+1?></td><td><?=$pname?></td>
<td>$ <?=get_price($pid)?></td>
<td><input type="text" name="product<?=$pid?>" value="<?=$q?>" maxlength="3" size="2" /></td>
<td>$ <?=get_price($pid)*$q?></td>
<td><a href="javascript:del(<?=$pid?>)">Remove</a></td></tr>
<?php
}
?>
<tr><td><b>Order Total: $<?=get_order_total()?></b></td><td colspan="5" align="right"><input type="button" value="Clear Cart" onclick="clear_cart()"><input type="button" value="Update Cart" onclick="update_cart()">
</td></tr>
<?php
}
else{
echo "<tr bgColor='#FFFFFF'><td>There are no items in your shopping cart!</td>";
}
?>
</table>
</div>
</form>
<form action="https://www.paypal.com/cgi-bin/webscr" method="post">
<input type="image" src="https://www.paypal.com/en_US/i/btn/btn_xpressCheckout.gif" style="margin-left:500px; margin-top:20px;">
<input type="hidden" name="cmd" value="_cart">
<input type="hidden" name="upload" value="1">
<input type="hidden" name="business" value="pankaj.gargas@gmail.com">
<?php
if(is_array($_SESSION['cart'])){
$max=count($_SESSION['cart']);
$a=1;
foreach($_SESSION['cart'] as $item){
$name=get_product_name($a);
?>
<input type="hidden" name="item_name_<?php echo $a; ?>" value="<?=$name; ?>">
<input type="hidden" name="quantity_<?php echo $a; ?>" value="<?= $item['qty']; ?>">
<input type="hidden" name="amount_<?php echo $a; ?>" value="$ <?=get_price($a)?>">
<?php
$a++;
}
}?>
</form>
此代码无效。有一个session_start()和重定向，但之前有输出：<div id="central_content">。
我想，以前有<html>和其他HTML标记。
在进行任何输出之前移动这些代码。
并且在header('location ...');之后添加die();