dpd66100 2017-04-29 06:59
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如何在会话中定义索引“UserName”？

I'm trying to show the login form to visitors only and hide it when user is logged in. I've seen similar question here but I couldn't get the answer. In the current code I get the Login form which is included from another page and also an error " Undefined index: UserName". So how can I define it? 

<?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>
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3条回答 默认 最新

  • douzhanhui5662 2017-04-29 07:20
    关注

    You need to check session right way if($_SESSION['UserName'] == "") {

    You can use isset and empty for checking session.

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

    you can also use array_key_exists instend of isset

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

    Above methods for (especially for array keys) it works and also you can go for 

    if (!isset($_SESSION['UserName']) || $_SESSION['UserName'] == '')
    本回答被题主选为最佳回答 , 对您是否有帮助呢?
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