必须重新加载页面才能解析if语句 - Have to reload page for if statement to be parsed

第一:代码!

loginform.html

<form action="" method="post" id="loginform">
                <h3>Login</h3>
                <input type="text" name="username" placeholder="Username">
                <br>
                <br>
                <input type="password" name="password" placeholder="Password">
                <br>
                <input type="submit" name="logsubmit" value="Login" class="registerbutton">
            </form>

login.php

<?php 
require_once("../resources/config.php");
require_once("../resources/library/dbconnect.php");
function checkUser($con) {
   if (isset($_POST['username']) && isset($_POST['password'])){
            $username = $_POST['username'];
            $pw       = md5($_POST['password']);
$sql="SELECT * FROM `users` WHERE username='$username' and pw='$pw'";
       $result = mysqli_query($con, $sql);
       $row    = mysqli_fetch_assoc($result);
    if ($result==true && $username == $row["username"] && $pw==$row["pw"]) {

            $_SESSION["logged_in"] = 1;
            $_SESSION["admin"] = $row["admin"];
            $_SESSION["username"] = $row["username"];
        }
        else {
        $msg = "Das war nichts! Passwort oder Username falsch? <br>".mysqli_error($con);
        unset($_SESSION["logged_in"]);
        }
    }
}
checkUser($connection);
header('location: ../public_html/index.php');
exit;
?>

index.php

<?php
session_start();
?>
<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>Barstone</title>
    <link rel="stylesheet" href="css/default.php" type="text/css">
    <link href='http://fonts.googleapis.com/css?family=Bitter:700&subset=latin,latin-ext' rel='stylesheet' type='text/css'>
</head>
<body>
    <?php require_once("../resources/config.php");
          require_once("../resources/library/header_nav.php");?>
    <div class="pagewrapper">
        <div class="register-container">
            <?php if(!isset($_SESSION['logged_in']) || !isset($_POST['regsubmit']))           
            {require_once("../resources/library/registerform.php");}
             if (isset($_POST['regsubmit']) && $_SESSION['register_check']==true) {printf("Success! Welcome %s!",$_POST['username']);}
            ?>
        </div>

        <div class="login-container">
            <?php if (isset($_SESSION['logged_in'])) { printf ("<form action='../resources/library/logout.php' method='post' id='loginform'><h3> Hello %s!                           </h3> Nice to see you!<input type='submit' class='logoutbutton' value='logout'>                                         </form>",$_SESSION["username"]);
       }?>
             <?php if (isset($_POST["logsubmit"])) {require_once("../resources/library/login.php"); 
                        }
else { if (!isset($_SESSION['username'])) {require_once("../resources/library/loginform.html");}}
                ?>
        </div>
        <div class="content">
        <?php require_once("../resources/library/articles.php");?>
        </div>
    </div>
</body>
</html>

relevant index.php part

    {printf ("<form action='../resources/library/logout.php' method='post' id='loginform'>
   <h3> Hello %s!</h3> Nice to see you!
   <input type='submit' class='logoutbutton' value='logout'>
   </form>",$_SESSION["username"]);}
    ?>
   <?php if (isset($_POST["logsubmit"])) {require_once("../resources/library/login.php");}
        else {if (!isset($_SESSION['username'])) 
               {require_once("../resources/library/loginform.html");}
                 }?>
 </div>

这应该做什么:

如果用户未登录，显示loginform.html。如果登录按钮被按下，使用login.php来登录用户。

当用户使用登录表单登录网站后，它会显示一个小的欢迎信息和一个用于注销的新按钮。

显示登录表单工作正常。

有人登录后，无显示。但是在重新加载页面后，按钮在那里并且工作正常

$_SESSION['logged_in']变量是在登录时设置的，但是为什么页面需要重新加载才能正确解释该语句呢?

我承认我这样做不一定是"最佳实践"，我愿意接受任何建议。仍然在学习。:)

测试:http://hsturnierv2.pixelpioniere.net/public_html/index.php登录为"test"与pw"test"

你在做什么?

<?php if (isset($_SESSION['logged_in'])) 
    // output something
?> 
<?php 
if (isset($_POST["logsubmit"])) { 
     // process login with login.php
} else {
     if (!isset($_SESSION['username'])) {
        //display login form   
     }
?>

好吧，这里发生了什么…

用户第一次访问网站。(未登录且未提交登录表单)
$_SESSION['logged_in']未设置并且//输出未到达的内容
$_POST['logsubmit']未设置，$_SESSION ['username']未设置所以登录表单显示为
用户提交Loginform$_SESSION['logged_in']未设置并且//输出未到达的内容
$_POST['logsubmit']设置并调用login.php如果login.php中没有输出，页面将保持空白。我假设你在login.php
用户登录后重新加载页面$_SESSION['logged_in']现在设置->你到达//输出一些

我个人会在一个单独的文件中处理登录:

<?php 
if(!isset($_SESSION['logged_in'])) {
    // redirect to login.php
}
?>
// here comes the content when user is logged in

在login:

<?php 
    if(isset($_POST['logsubmit']) {
         // handle login and redirect to page that needs login if successfull 
    }
    if($loginError) { // print login errors }
    // print login form 
?>

编辑:不要忘记session_start()(在包含的文件中session_start()是不必要的)

问题很可能是你有

header('location: ../public_html/index.php');

代替:

header('Location: ../public_html/index.php');

更新

所以你重定向，但你的脚本死于某种原因。这不是一个逻辑错误，而是一个致命的脚本错误，杀死你的脚本之前，它可以输出更多的东西…你的代码是:

<?php if (isset($_SESSION['logged_in'])) 
{ 
    printf ("<form action='../resources/library/logout.php' method='post' id='loginform'>
    <h3> Hello %s!</h3> Nice to see you!
    <input type='submit' class='logoutbutton' value='logout'>                                          
    </form>",$_SESSION["username"]);
   }
?>
<?php if (isset($_POST["logsubmit"])) 
{
    require_once("../resources/library/login.php"); 
}else 
{ 
    if (!isset($_SESSION['username'])) {require_once("../resources/library/loginform.html");
    }
}
?>

所以我明白了。当有人实际登录index.php时，需要一个login.php，完成后会发送一个重定位头并退出。但是输出已经开始了!你已经漏了半页了!因此，头发出一个错误(可能由于php.ini设置而不显示)，然后退出。因此你得到了半页。

你应该把你的index.php代码改成:

<?php
session_start();
if (isset($_POST["logsubmit"])) 
{
    require_once("../resources/library/login.php"); 
}
?>
<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>Barstone</title>
    <link rel="stylesheet" href="css/default.php" type="text/css">
    <link href='http://fonts.googleapis.com/css?family=Bitter:700&subset=latin,latin-ext' rel='stylesheet' type='text/css'>
</head>
<body>
    <?php require_once("../resources/config.php");
          require_once("../resources/library/header_nav.php");?>
    <div class="pagewrapper">
        <div class="register-container">
            <?php if(!isset($_SESSION['logged_in']) || !isset($_POST['regsubmit']))           
            {
                 if (isset($msg)) echo $msg .'<br>';
                 require_once("../resources/library/registerform.php");}
             if (isset($_POST['regsubmit']) && $_SESSION['register_check']==true) {printf("Success! Welcome %s!",$_POST['username']);}
            ?>
        </div>

        <div class="login-container">
            <?php if (isset($_SESSION['logged_in'])) { printf ("<form action='../resources/library/logout.php' method='post' id='loginform'><h3> Hello %s!                           </h3> Nice to see you!<input type='submit' class='logoutbutton' value='logout'>                                         </form>",$_SESSION["username"]);
       }else { if (!isset($_SESSION['username'])) {require_once("../resources/library/loginform.html");}}
                ?>
        </div>
        <div class="content">
        <?php require_once("../resources/library/articles.php");?>
        </div>
    </div>
</body>
</html>

这可以防止在header之前输出，并且如果您输入错误的凭据也会显示错误。然后，您还应该更改您的login.php文件，以便它不会每次都重定向，而只在登录成功时重定向，如下所示:

<?php 
require_once("../resources/config.php");
require_once("../resources/library/dbconnect.php");
function checkUser($con) {
   if (isset($_POST['username']) && isset($_POST['password'])){
            $username = $_POST['username'];
            $pw       = md5($_POST['password']);
$sql="SELECT * FROM `users` WHERE username='$username' and pw='$pw'";
       $result = mysqli_query($con, $sql);
       $row    = mysqli_fetch_assoc($result);
    if ($result==true && $username == $row["username"] && $pw==$row["pw"]) {

            $_SESSION["logged_in"] = 1;
            $_SESSION["admin"] = $row["admin"];
            $_SESSION["username"] = $row["username"];
            $msg='OK';
        }
        else {
        $msg = "Das war nichts! Passwort oder Username falsch? <br>".mysqli_error($con);
        unset($_SESSION["logged_in"]);
        }
    }
    return $msg
}
$result = checkUser($connection);
if ($msg=='OK')
{
    header('location: ../public_html/index.php');
    exit;
}
?>