SESSION doesn't get SET PHP - SESSION doesn't get SET PHP

我有个问题。当我登录时，它做得很好。它说您以$username = admin…但当我刷新登录页面时，它不再说了。它给了我登录和密码字段，所以我可以重新登录。我猜会话没有设置好，但我似乎找不到问题。它甚至说我的密码不正确但仍然告诉我你以admin登录，这是我的用户名谢谢

<?php
session_start();
include("connect.php");
if ($_POST['submit']){
    $username = mysql_real_escape_string($_POST['username']);
    $password = mysql_real_escape_string($_POST['password']);
    if($username){
        if($password){
            $password =     md5(md5("KmsdufIFNKSnefndbdo19228330293".$password."JSDSHBFJS8S8ds8sd8s8d"));
            $query = mysql_query("SELECT * FROM user WHERE      username='$username'");             
            $num_rows = mysql_num_rows($query);
            if ($num_rows == 1){
                $row = mysql_fetch_assoc($query);
                $db_username = $row['username'];
                $db_password = $row['password'];
                if ($password == $db_password){
                    $username =$_SESSION['username'];
                }else
                    echo "Your password is incorrect";
            }else{
                echo "Username not Found";
            }
        }
    }else
        echo "Futeni emrin e llogarise.";
}
?>
 <html>
 <head>
 </head>
<body>
<?php
if ($username){
    echo "You are logged in as, ".$username."!. <a href='logout.php'>LogOut</a> ";
}else{
    echo "
    <form action='login.php' method='post'>
        Username: <input type='text' name='username' id='user'/>
        <br/>
        Password: <input type='password' name='password' id='pass'/>
        <br/>
        <input type='submit' name='submit' value='Submit'/>
    </form>
    ";
}
?>
   </body>
 </html>

$username的值在if ($_POST['submit']){中设置，所以当您刷新登录页面时，它不再说了。您应该将$username设置为会话

<?php
session_start();
include("connect.php");
if ($_POST['submit']){
    $username = mysql_real_escape_string($_POST['username']);
    $password = mysql_real_escape_string($_POST['password']);
    if($username){
        if($password){
            $password =     md5(md5("KmsdufIFNKSnefndbdo19228330293".$password."JSDSHBFJS8S8ds8sd8s8d"));
            $query = mysql_query("SELECT * FROM user WHERE      username='$username'");             
            $num_rows = mysql_num_rows($query);
            if ($num_rows == 1){
                $row = mysql_fetch_assoc($query);
                $db_username = $row['username'];
                $db_password = $row['password'];
                if ($password == $db_password){
                   $_SESSION['username']= $username;
                }else
                    echo "Your password is incorrect";
            }else{
                echo "Username not Found";
            }
        }
    }else
        echo "Futeni emrin e llogarise.";
}
?>
 <html>
 <head>
 </head>
<body>
<?php
if ( isset($_SESSION['username']) && $_SESSION['username'] != '' ){
   $username = $_SESSION['username'];
    echo "You are logged in as, ".$username."!. <a href='logout.php'>LogOut</a> ";
}else{
    echo "
    <form action='login.php' method='post'>
        Username: <input type='text' name='username' id='user'/>
        <br/>
        Password: <input type='password' name='password' id='pass'/>
        <br/>
        <input type='submit' name='submit' value='Submit'/>
    </form>
    ";
}
?>
   </body>
 </html>

首先要将username设置为session变量

if ($password == $db_password){
   $username =      mysql_real_escape_string($_SESSION['username']);
   $_SESSION['username'] = $username;
} else {
   echo "Your password is incorrect";
}

在if条件下，您需要更改以下代码

$username = isset($_SESSION['username']) ? $_SESSION['username'] : null;
if ($username){
    echo "You are logged in as, ".$username."!. <a href='logout.php'>LogOut</a> ";
}else{
   /* your code */
}

您正在进行相反的设置。试着

if ($password == $db_password){
                    $_SESSION['username'] =  $username;
}

然后

if (isset($_SESSION['username']))
{
  echo "You are logged in as, $_SESSION['username']!. <a href='logout.php'>LogOut</a>";
}