Question

我试图仅向访问者显示登录表单，并在用户登录时隐藏它。我在这里看到了类似的问题，但我无法得到答案。在当前的代码中，我得到了另一个页面中包含的登录表单，也是一个错误＆＃34;未定义的索引：UserName＆＃34;。那我怎么定义呢？

<?php session_start() ?>
<!DOCTYPE html>
<html>
<head>
    <title>Home</title>
    <meta charset="utf-8"/>
    <link rel="stylesheet" href="IndexStyle.css"/>
    <meta name="viewport" content="width= device-width, intial-scale=1.0">

</head>
<body class="body">
    <header class="MainHeader">
    <img src="images/header-image-5.jpg">
    <nav><ul>
         <li class="active"><a href="index.php">Home</a></li>
         <li><a href="Product.php">Products</a></li>
         <li><a href="AboutUs.php">About Us</a></li>
         <li><a href="ContactUs.php">Contact Us</a></li>
         <div id="AdminP">
            <li><a href="AdminPanel.php">Admin Panel</a></li>
         </div>
        </ul>
    </header>
    <div class="MainBody">
        <p>This is Mainbody 
        </p>
    </div>
    <aside class="SideBar">
        <div class="login">
<?php
    if($_SESSION['UserName'] == "") {

        include 'Form.php';
    } else {
        echo "Logged in";
    }
?>
        </div>        
      <p>&nbsp;</p>
    </aside>
    <Footer class="Footer"> 
        <p>Copyrights reserved 
        </p>
    </Footer>
</body>
</html>

Answer 1

您需要以正确的方式检查会话if($_SESSION['UserName'] == "") {

您可以使用isset和empty来检查会话。

session_start();
if(isset($_SESSION['UserName']) && !empty($_SESSION['UserName']))
{
include 'Form.php';
}
else {
echo "Logged in";
}

你也可以使用array_key_exists插入isset

session_start();
if(array_key_exists('UserName',$_SESSION) && !empty($_SESSION['UserName'])) {
include 'Form.php';
}else{
echo "Logged in";
}

上面的方法（尤其是数组键）它可以工作，你也可以去

if (!isset($_SESSION['UserName']) || $_SESSION['UserName'] == '')

Answer 2

试试这个亲爱的改变你的PHP代码

<?php
    if(!(isset($_SESSION['UserName']) && $_SESSION['UserName'] != "")) 
    {
      echo "Logged in";
    } 
    else 
    {
     include 'form.php';
    }
?>

Answer 3

import urllib2
from bs4 import BeautifulSoup
import csv
import lxml
import xlrd

page = urllib2.urlopen(quote_page)
soup = BeautifulSoup(page, 'lxml')
titleTag = soup.html.head.title
titleTag = titleTag.text.strip()
p_class = soup.find('p')
p_class = p_class.text.strip()
d_class = soup.find('div', class_="property-value__price")
d_class = d_class.string.strip()
e_class = soup.find('p', class_="property-value__agent")
e_class = e_class.string.strip()

print titleTag, p_class, d_class, e_class
with open('index2.csv', 'a') as csv_file:
    writer = csv.writer(csv_file)
    writer.writerow([titleTag, p_class, d_class, e_class])

希望这会对你有所帮助

如何定义索引＆＃34; UserName＆＃34;在会话中？

3 个答案: