PHP刷新页面将变量重新初始化为0
我正在使用URLPHP刷新页面将变量重新初始化为0,php,Php,我正在使用URL?action=add向购物车添加项目。我没有初始化变量$count,并且出现以下错误: Notice: Undefined index: count in C:\wamp\www\cart.php on line 31 Notice: Undefined index: count in C:\wamp\www\cart.php on line 32 我知道我需要定义$count变量。($count=0;)但我不希望每次用户向购物车添加新项目时,页面都会刷新,并将会话变量重置
?action=add
向购物车添加项目。我没有初始化变量$count
,并且出现以下错误:
Notice: Undefined index: count in C:\wamp\www\cart.php on line 31
Notice: Undefined index: count in C:\wamp\www\cart.php on line 32
我知道我需要定义$count变量。($count=0;)但我不希望每次用户向购物车添加新项目时,页面都会刷新,并将会话变量重置为0。$count需要在下一页用作计数器。我该怎么做
这是我的案例代码:
switch($action) {
case "add":
if (isset($_SESSION['cart'][$comic_id])) {
$count=$_SESSION['count']; //LINE 31
$_SESSION['count']++; //LINE 32
$_SESSION['cart'][$comic_id]++;
} else {
$_SESSION['cart'][$comic_id] = 1;
}
break;
添加if(!isset($\u会话['count'])后,$\u会话['count']=1
<?php
if(!isset($_SESSION)) {
session_start();
}
$total = 0;
$page = 'cart';
$dbname = "crystal_fusion";
$dbhost = "127.0.0.1";
$dbuser = "root";
$dbpwd = "";
$link = mysql_connect($dbhost, $dbuser, $dbpwd);
mysql_select_db($dbname);
if(isset($_GET['comic_id'])){
$comic_id = $_GET['comic_id'];
} else {
$comic_id = NULL;}
$action = $_GET['action'];
if($comic_id && !productExists($comic_id)) {
die("We apologise, but we can't seem to find the comic you were looking for!!!");
}
if (!isset($_SESSION['count'])) $_SESSION['count'] = 1; //added as suggested - now output is correct when adding multiples of 1 item. However, the count is wrong if more than 1 item is added.
switch($action) {
case "add":
if (isset($_SESSION['cart'][$comic_id])) {
$count=$_SESSION['count'];
$_SESSION['count']++;
$_SESSION['cart'][$comic_id]++;
} else {
$_SESSION['cart'][$comic_id] = 1;
}
break;
case "remove":
if (isset($_SESSION['cart'][$comic_id])) {
$_SESSION['cart'][$comic_id]--;}
if($_SESSION['cart'][$comic_id] == 0) unset($_SESSION['cart'][$comic_id]);
break;
case "empty":
unset($_SESSION['cart']);
session_destroy();
break;
}
require('header.php');
require('sidebar.php');
if (isset($_SESSION['cart'][$comic_id])){
echo "<table border=\"0\" padding=\"10\" width=\"80%\">";
echo "<td colspan=\"1\" align=\"left\"><a href=\"title.php\">Continue Shopping</a></div>";
echo "<td colspan=\"6\" align=\"right\"><a href=\"$_SERVER[PHP_SELF]?action=empty\" onclick=\"return confirm('Crystal Fusion: Are you sure you wish to empty your cart?');\">Empty Cart</a></td>"; //empty cart link --Sam
echo "<tr height=\"20px\">";
echo "<tr height=\"20px\">";
echo "<td align=center>Image</td><td align=center>Title</td><td align=center>Description</td><td colspan=3 align=center>Copies (+/-)</td><td align=center>Price</td>";
echo "<tr height=\"20px\">";
foreach($_SESSION['cart'] as $comic_id => $qty) {
$sql = sprintf("SELECT title, description, cost, image_thumbnail
FROM comic
WHERE comic_id = %d;",$comic_id);
$result = mysql_query($sql);
if(mysql_num_rows($result) > 0) {
list($name, $description, $price, $image_thumbnail) = mysql_fetch_row($result);
$cost = $price * $qty;
$total = $total + $cost;
$cost = number_format($cost,2);
$total = number_format($total,2);
$description = substr($description, 0, 250);
echo "<br><tr>";
echo "<td width=\"10px\" align=\"center\"><img height=100 align=center src=\"$image_thumbnail\">";
echo "<td align=\"center\">$name</td>";
echo "<td width=\"40%\" align=\"center\">$description...<a href=comic_dyn.php?comic_id=$comic_id>More Info</td>";
echo "<td width=\"30px\" align=\"center\"><a href=\"$_SERVER[PHP_SELF]?action=add&comic_id=$comic_id\">+<br></a><td align=\"center\">$qty <td width=\"20px\" align=\"center\"><a href=\"$_SERVER[PHP_SELF]?action=remove&comic_id=$comic_id\">-</a></td>";
echo "<td align=\"right\">$$cost</td>";
echo "</tr>";
}
}
echo "<br><tr><tr height=100px>";
echo "<td><td><td colspan=\"4\" align=\"right\">Total:</td>";
echo "<td width=\"60px\" align=\"right\">$$total</td>";
echo "<tr><td colspan=\"7\" align=\"right\"><a href=\"checkout_html.php\">Proceed to Checkout</a>";
echo "<tr height=\"50px\">";
echo "</table>";
}else{
echo "Your cart is currently empty.";
echo "<br><br><td colspan=\"1\" align=\"left\"><a href=\"title.php\">Continue Shopping</a></div>";
}
$_SESSION['totnamqty'][]=$name . " " . $qty . " " . $price;
function productExists($comic_id) {
$sql = sprintf("SELECT * FROM comic WHERE comic_id = %d;", $comic_id);
return mysql_num_rows(mysql_query($sql)) > 0;
}
?>
检查以下各项:
您必须使用session_start()初始化会话代码>作为第一个
在分配或执行som操作之前,请确保$\u会话['count']
存在并已初始化
检查以下各项:
您必须使用session_start()初始化会话代码>作为第一个
在分配或执行som操作之前,请确保$\u会话['count']
存在并已初始化
在使用某处$\u会话['count']
之前,必须对其进行初始化。我认为您没有这样做,这就是您收到通知的原因。在使用某处$\u会话['count']
之前,您必须初始化它。我认为您没有这样做,这就是您收到通知的原因。有关更多会话信息,请参阅以下链接:
(我会发布PHP.net手册页面,但我是新手,只能发布2个链接)
此外,您可能还希望转换为使用$\u POST变量,而不是通过URL传递键值对:
有关更多会话信息,请参阅以下链接:
(我会发布PHP.net手册页面,但我是新手,只能发布2个链接)
此外,您可能还希望转换为使用$\u POST变量,而不是通过URL传递键值对:
是会话\u启动已初始化。如果我将$_SESSION['count']=0;然后每次刷新页面时,计数将设置为0。我不希望发生这种情况。$count
和$\u SESSION
变量的初始化?有什么方法可以解决这个问题吗?一种方法是,如果没有任何问题,显示完整的PHP代码。:)这样我们就可以看到你哪里出了问题。:)是会话启动已初始化。如果我将$_SESSION['count']=0;然后每次刷新页面时,计数将设置为0。我不希望发生这种情况。$count
和$\u SESSION
变量的初始化?有什么方法可以解决这个问题吗?一种方法是,如果没有任何问题,显示完整的PHP代码。:)这样我们就可以看到你哪里出了问题。:)是的,但是如果我将其初始化为0,每次刷新页面时计数都将重置为0。@Sam:所以,只有在尚未设置的情况下才进行设置<代码>如果(!isset($\u会话['count'])$\u会话['count']=0代码>初始化$_会话['count']=1如果用户处于登录状态如果我的答案有用,请单击我的答案作为正确答案,并请向上投票我的答案。。谢谢你,伙计…检查一下为什么计数在增加。。。或者,如果您不想增加计数并使其保持常量,请将其定义为常量,但如果我将其初始化为0,则每次刷新页面时,计数都将重置为0。@Sam:因此,仅当尚未设置时才进行设置<代码>如果(!isset($\u会话['count'])$\u会话['count']=0代码>初始化$_会话['count']=1如果用户处于登录状态如果我的答案有用,请单击我的答案作为正确答案,并请向上投票我的答案。。谢谢你,伙计…检查一下为什么计数在增加。。。或者,如果您不想增加计数并使其保持不变,请将其定义为常量