Question

我有这个PHP代码：

    <nav><ul>
        <?php

if( (isset($_SESSION['user_role']) ) && (false != $_SESSION['user_role']) )
{
    if( '2' == $_SESSION['user_role'] ) 
    { 
        echo "<li><a href='index.php'>Home</a></li>";
        echo "<li><a href='#'>About Us</a></li>";
        echo "<li><a href='#'>Contact Us</a></li>";
        echo "<li><a href='loginpage.php'>Login</a></li>";
    } 

    elseif ('3' == $_SESSION['user_role'] ) 
    { 
        echo "<li><a href='index.php'>Home</a></li>";
        echo "<li><a href='#'>About Us</a></li>";
        echo "<li><a href='#'>Contact Us</a></li>";
        echo "<li><a href='loginpage.php'>Login</a></li>";
        echo "<li><a href='#'>Admin</a></li>";
    } 


}


?>
    <ul></nav>

出于某种原因，当我在浏览器上运行php文件时，正在回显的html代码没有显示。

有什么建议吗？

这是我设置会话变量的地方：

$con = mysqli_connect("localhost","root","","darrenvellaedp2") or die("Error: " . mysqli_error($con));

                $result = "SELECT userRoleID FROM tbl_users WHERE userRoleID = 2" or die("Error: " . mysqli_error($con));

                $res = $con->query($result);

                while($row = mysqli_fetch_array($res)) {
                    $UserRoleID = $row['userRoleID'];

                    $_SESSION['user_role'] = $UserRoleID;
                }

Answer 1

如果没有生成输出，则表示您的第一个条件IF语句失败。即：

if( (isset($_SESSION['user_role']) ) && (false != $_SESSION['user_role']) )

您应该添加var_dump($_SESSION['user_role'])以检查会话数据是否存在。

P.S。你还记得在这个剧本的开头添加session_start();吗？即..

<?php

// start php session
session_start();

?>
<nav><ul>

    // rest of your code

Answer 2

试试这个：

第一页

<?php
session_start();   

 $con = mysqli_connect("localhost","root","","darrenvellaedp2") or die("Error: " . mysqli_error($con));

                    $result = "SELECT userRoleID FROM tbl_users WHERE userRoleID = 2" or die("Error: " . mysqli_error($con));

                    $res = $con->query($result);

                    while($row = mysqli_fetch_array($res)) {
                        $UserRoleID = $row['userRoleID'];

                        $_SESSION['user_role'] = $UserRoleID;
                    }
?>

第二页

<?php
session_start();
?>

<nav><ul>
<?php

if( (isset($_SESSION['user_role']) ) && (false != $_SESSION['user_role']) )
{
    if( '2' == $_SESSION['user_role'] ) 
    { 
        echo "<li><a href='index.php'>Home</a></li>";
        echo "<li><a href='#'>About Us</a></li>";
        echo "<li><a href='#'>Contact Us</a></li>";
        echo "<li><a href='loginpage.php'>Login</a></li>";
    } 

    elseif ('3' == $_SESSION['user_role'] ) 
    { 
        echo "<li><a href='index.php'>Home</a></li>";
        echo "<li><a href='#'>About Us</a></li>";
        echo "<li><a href='#'>Contact Us</a></li>";
        echo "<li><a href='loginpage.php'>Login</a></li>";
        echo "<li><a href='#'>Admin</a></li>";
    } 


}


?>
    </ul></nav>

Answer 3

接下来，将条件session_status放在您共享的第一个代码段中：

<?php

if (session_status() == PHP_SESSION_NONE) {
    session_start();
}

$con = mysqli_connect("localhost","root","","darrenvellaedp2") or die("Error: " . mysqli_error($con));
$sql = "SELECT userRoleID FROM tbl_users WHERE userRoleID = 2";
$res = $con->query($sql) or die("Error: " . mysqli_error($con));

$row = mysqli_fetch_array($res);
$_SESSION['user_role'] = $row['userRoleID'];

?>

第二个print_r：

<nav><ul>

<?php

print 'user_role: ';
print_r($_SESSION['user_role']);

if( (isset($_SESSION['user_role']) ) && (false != $_SESSION['user_role']) )
{
    if( '2' == $_SESSION['user_role'] ) 
    { 
        echo "<li><a href='index.php'>Home</a></li>";
        echo "<li><a href='#'>About Us</a></li>";
        echo "<li><a href='#'>Contact Us</a></li>";
        echo "<li><a href='loginpage.php'>Login</a></li>";
    } 

    elseif ('3' == $_SESSION['user_role'] ) 
    { 
        echo "<li><a href='index.php'>Home</a></li>";
        echo "<li><a href='#'>About Us</a></li>";
        echo "<li><a href='#'>Contact Us</a></li>";
        echo "<li><a href='loginpage.php'>Login</a></li>";
        echo "<li><a href='#'>Admin</a></li>";
    } 
}

?>
</ul></nav>

并报告user_role:输出的内容。

回显HTML未输出

3 个答案: