数据未保存在会话变量中

Question

数据没有存储在会话中一切正常登录系统所有事情但是像用户名用户通行证和用户 ID 这样的数据应该保存在会话中但我不知道因为如果它在您成功登录时保存它应该显示欢迎{用户名}。

继续到论坛主页，但它没有显示之前显示的用户名，但我遇到了问题，当所有问题解决后，这个错误就出来了。

代码：

<style>
<?php include 'signin.css'; ?>
</style>
<script type="text/javascript" src="signup.js"></script>
<?php
//signin.php
include 'connect.php';
include 'header.php';
 
//first, check if the user is already signed in. If that is the case, there is no need to display this page
if(isset($_SESSION['signed_in']) && $_SESSION['signed_in'] == true)
{
    echo 'You are already signed in, you can <a href="signout.php">sign out</a> if you want.';
}
else
{
    if($_SERVER['REQUEST_METHOD'] != 'POST')
    {
        /*the form hasn't been posted yet, display it
          note that the action="" will cause the form to post to the same page it is on */
        echo '<form action="" method="post"  >
<div class="all" >
<div class="container" >
<div class="first" >
<h2>SIGN IN</h2>
</div>
<div class="user" >
<input class="use"  type="text" placeholder="Username" id="username" name="user_name" required>
</div>
<div class="userimg" >
<img  src="user.png" style="height:2em;width:2em;" >
</div>
<div class="pass" >
<input type="password" placeholder="Password" id="password"  name="user_pass" minlength="8" required  >
<img src="lock.png" >
</div>
<div class="show">
<img src="visible.png" id="visible" class="visible" onclick="myFunction()">
<img src="invisible.png" id="invisible"  class="invisible" onclick="mynot()" >
</div>
<div class="check" >
<input type="checkbox" required >
</div>
<div class="box" >
<p>I accept all <a href="#" >terms</a> and <a href="#" >privacy</a>.</p>
</div>
<div class="submit" >
<input type="submit" name="submit" onclick="submit()" value="Sign in">
</div>
<div class="close" >
<input type="button" value="Back"  >
</div>
<div class="log" >
dont have an account? <a href="#" >Login</a>
</div>
<div class="organic" >
<img src="logo.png" class="organicpe" >
</div>
<div>
<h2 class="back" ><a href="#" >Go Back</a></h2>
</div>
</div>
</div>
</form>';
    }
    else
    {
        /* so, the form has been posted, we'll process the data in three steps:
            1.  Check the data
            2.  Let the user refill the wrong fields (if necessary)
            3.  Verify if the data is correct and return the correct response
        */
        $errors = array(); /* declare the array for later use */
         
        if(!isset($_POST['user_name']))
        {
            $errors[] = 'The username field must not be empty.';
        }
         
        if(!isset($_POST['user_pass']))
        {
            $errors[] = 'The password field must not be empty.';
        }
         
        if(!empty($errors)) /*check for an empty array, if there are errors, they're in this array (note the ! operator)*/
        {
            echo 'Uh-oh.. a couple of fields are not filled in correctly..';
            echo '<ul>';
            foreach($errors as $key => $value) /* walk through the array so all the errors get displayed */
            {
                echo '<li>' . $value . '</li>'; /* this generates a nice error list */
            }
            echo '</ul>';
        }
        else
        {
            //the form has been posted without errors, so save it
            //notice the use of mysql_real_escape_string, keep everything safe!
            //also notice the sha1 function which hashes the password
            $sql = "SELECT 
                        user_id,
                        user_name,
                        user_level
                    FROM
                        Users
                    WHERE
                        user_name = '" . mysql_real_escape_string($_POST['user_name']) . "'
                    AND
                        user_pass = '" . sha1($_POST['user_pass']) . "'";
          
            $result = mysqli_query($conn,$sql);
            if(!$result)
            {
                //something went wrong, display the error
                echo 'Something went wrong while signing in. Please try again later.';
                //echo mysql_error(); //debugging purposes, uncomment when needed
            }
            else
            {
                //the query was successfully executed, there are 2 possibilities
                //1. the query returned data, the user can be signed in
                //2. the query returned an empty result set, the credentials were wrong
                if(mysqli_num_rows($result) == 0)
                {
                    echo 'You have supplied a wrong user/password combination. Please try again.';
                }
                else
                {
                    while ($row = $result -> fetch_row()) 
                    session_start();
                    //set the $_SESSION['signed_in'] variable to TRUE
                    $_SESSION['signed_in'] = true;
                     
                    //we also put the user_id and user_name values in the $_SESSION, so we can use it at various pages
                
                    {
                        $_SESSION['user_id']    = $row['user_id'];
                        $_SESSION['user_name']  = $row['user_name'];
                        $_SESSION['user_level'] = $row['user_level'];
                    }
                    while ($row = mysqli_fetch_array($result)) {
//set the $_SESSION['signed_in'] variable to TRUE
$_SESSION['signed_in'] = true;                  
//we also put the user_id and user_name values in the $_SESSION, so we can use it at various pages
while($row = mysqli_fetch_assoc($result))
{
    $_SESSION['user_id'] = $row['user_id'];
    $_SESSION['user_name'] = $row['user_name']; 
}
                     }
                    echo '<h3>Welcome, ' . $_SESSION['user_name'] . '. <a href="index.php">Proceed to the forum overview</a>.</h1>';
                }
            }
        }
    }
}

include 'footer.php';
?>

Answer 1

您需要启动每个 php 文件使用会话

session_start();