主要是购物车部分代码的讲解，和对session操作的php教程代码演示。
<?php
//
// add_item.php:
// add an item to the shopping cart.
//
session_start();
if (session_is_registered('cart')) {
session_register('cart');
}require 'lib.inc.php'; // loadproducts()
loadproducts(); // load products in $master_products_list
// make $curr_product global
$curr_product = array();// loop through all the products and pull up the product
// that we are interested in
foreach ($master_products_list as $prod_id => $product) {
if (trim($prod_id) == trim($_get[id])) {
$curr_product = $product;
}
}// register our session
//session_register('cart');
//if(session_is_registered('cart')) echo "已经注册";
if ($_post[ordered]) { // if they have chosen the product
array_push($_session[cart][products], array(trim($_post[id]), $_post[quantity]));
$_session[cart][num_items] += $_post[quantity];
}
?><html>
<head>
<title>
<?php if ($_post[ordered]) { ?>
已经添加 <?php echo $curr_product[name]; ?> 到您的购物篮
<?php } else { ?>
添加 <?php echo $curr_product[name]; ?> 到您的购物篮
<?php } ?>
</title>
</head>
<body>
<?php if ($_post[ordered]) { ?>
<h1><?php echo $curr_product[name]; ?>
添加至购物篮成功</h1><a href="cart.php">返回</a> 商品列表页面.
<?php } else { ?>
<h1>添加 <?php echo $curr_product[name]; ?> 到您的购物篮</h1><form action="<?php echo $php_self; ?>" method="post">
商品名称: <?php echo $curr_product[name]; ?>
<br>
商品说明: <?php echo $curr_product[desc]; ?>
<br>
商品单价: rmb<?php echo $curr_product[price]; ?>
<br>
商品数量: <input type="text" size="7" name="quantity">
<input type="hidden" name="id" value="<?php echo $_get[id]; ?>">
<input type="hidden" name="ordered" value="1"><input type="submit" value="添加至购物栏">
</form>
<?php } ?>
</body>
</html>
php代码
<?php
//
// cart.php: the main file
//
session_start();require 'lib.inc.php';
//判断购物篮会话变量cart是否注册，不注册则注册cart变量
if (session_is_registered('cart')) {
session_register('cart');
}// 如果购物篮没有初始化，则初始化购物篮
if (!isset($_session[cart][num_items])) {
$_session[cart] = array("num_items" => 0,
"products" => array());
}// from site_lib.inc, loads the $master_products_list array
loadproducts(); //载入物品列表
?><html>
<head>
<title>演示会话跟踪的购物篮程序</title>
</head><body>
<h1>欢迎进入网上商店</h1>
<?php
if ($_session[cart][num_items]) { // if there is something to show
?>
<h2>当前在购物篮里的物品</h2>
<br>
<table border="2" cellpadding="5" cellspacing="2">
<tr>
<th>
商品名称
</th>
<th>
商品说明
</th>
<th>
单价
</th>
<th>
数量
</th>
<th>
</th>
</tr>
<?php
// loop through the products
foreach ($_session[cart][products] as $i => $product) {
$product_id = $product[0];
$quantity = $product[1];$total += $quantity *
(double)$master_products_list[$product_id][price];
?>
<tr>
<td>
<?php echo $master_products_list[$product_id][name]; ?>
</td>
<td>
<?php echo $master_products_list[$product_id][desc]; ?>
</td>
<td>
<?php echo $master_products_list[$product_id][price]; ?>
</td>
<td>
<form action="change_quant.php" method="post">
<input type="hidden" name="id" value="<?php echo $i; ?>">
<input type="text" size="3" name="quantity"
value="<?php echo $quantity; ?>">
</td>
<td>
<input type="submit" value="数量更改">
</form>
</td>
</tr>
<?php
}
?>
<tr>
<td colspan="2" align="right">
<b>合计: </b>
</td>
<td colspan="2">
rmb：<?php echo $total; ?>
</td>
<td> </td>
</tr>
</table>
<br>
<br>
<?php
}
?><h2>商店待出售的商品</h2>
<br>
<i>
我们提供以下商品待售:
</i>
<br>
<table border="2" cellpadding="5" cellspacing="2">
<tr>
<th>
商品名称
</th>
<th>
商品说明
</th>
<th>
单价
</th>
<th>
</th>
</tr>
<?php
// show all of the products
foreach ($master_products_list as $product_id => $item) {
?>
<tr>
<td>
<?php echo $item[name]; ?>
</td>
<td>
<?php echo $item[desc]; ?>
</td>
<td>
$<?php echo $item[price]; ?>
</td>
<td>
<a href="add_item.php?id=<?php echo $product_id; ?>">
添加至购物篮
</a>
</td>
</tr>
<?php
}?>
</table>
购物车
<?php
//
// change_quant.php:
// change the quantity of an item in the shopping cart.
//
session_start();
if (session_is_registered('cart')) {
session_register('cart');
}// typecast to int, making sure we access the
// right element below
$i = (int)$_post[id];// save the old number of products for display
// and arithmetic
$old_num = $_session[cart][products][$i][1];if ($_post[quantity]) {
$_session[cart][products][$i][1] = $_post[quantity]; //change the quantity
} else {
unset($_session[cart][products][$i]); // send the product into oblivion
}// update the number of items
$_session[cart][num_items] = ($old_num >$_post[quantity]) ?
$_session[cart][num_items] - ($old_num-$_post[quantity]) :
$_session[cart][num_items] + ($_post[quantity]-$old_num);
?><html>
<head>
<title>
数量修改
</title>
</head>
<body>
<h1> 将数量： <?php echo $old_num; ?> 更改为
<?php echo $_post[quantity]; ?></h1>
<a href="cart.php">返回</a> 商品列表页面.
</body>
</html>
打开文件
<?php
//物品数组
$master_products_list = array();//载入物品数据函数
function loadproducts() {
global $master_products_list;
$filename = 'products.txt';$fp = @fopen($filename, "r")
or die("打开 $filename 文件失败");
@flock($fp, 1)
or die("锁定 $filename 文件失败");//读取文件内容
while ($line = fgets($fp, 1024)) {
list($id, $name, $desc, $price) = explode('|', $line); //读取每行数据，数据以| 格开
$id = trim($id); //去掉首尾特殊符号
$master_products_list[$id] = array("name" => $name, //名称
"desc" => $desc, //说明
"price" => $price); //单价
}@fclose($fp) //关闭文件
or die("关闭 $filename 文件失败");
}
?>