Question

这是我的代码......我无法弄清楚为什么一直在说

Warning: Cannot modify header information - headers already sent by (output started at /opt/apache/htdocs/save/header.php:10) in /opt/apache/htdocs/****/attendance.php on line 41

Warning: Cannot modify header information - headers already sent by (output started at /opt/apache/htdocs/save/header.php:10) in /opt/apache/htdocs/****/attendance.php on line 42

我只想让登录页面正常工作。我还想将$ _SERVER [PHP_SELF（）]更改为实际的url，以便我的css等仍可正常工作。

include('header.php');
$server = "serverName";
$dUsername = "username";
$dPass = "password";
$username = "username2";
$password = "password2";
$randomword = "randomword";

if(isset($_COOKIE['MyLoginPage'])) {
    if($_COOKIE['MyLoginPage'] == md5($password.$randomword)) {
        $conn = mysql_connect($server, $dUsername, $dPass) or die("error connecting to MySQL database");
        mysql_select_db("w3_save", $conn);
        $query = "SELECT DISTINCT MemberName FROM attendance;";
        $result = mysql_query($query, $conn) or die(mysql_error());
        echo "<div id='rightColumn'><div id='title'><h1>Attendance</h1></div><div id='content'>";
        while($row = mysql_fetch_array($result, MYSQL_ASSOC)) {
            echo "Name: $row[MemberName] <br />";
        }
        echo "</div></div></body></html>";

        mysql_close($conn);
        exit;
    }
    else {
        echo "<p>Bad Cookie. Please clear them out and try again</p>";
        exit;
    }
}

if(isset($_GET['p']) && $_GET['p'] == 'login') {
    if($_POST['name'] != $username) {
        echo "<p>Sorry the username you entered is incorrect.</p>";
        exit;
    }
    else if($_POST['pass'] != $password) {
        echo "<p>Sorry the password you entered is incorrect.</p>";
        exit;
    }
    else if($_POST['name'] == $username && $_POST['pass'] == $password) {
        **setcookie('MyLoginPage', md5($_POST['pass'].$randomword));  LINE 41
        header("Location: $_SERVER[PHP_SELF]");** LINE 42
    } else {
        echo "<p>Sorry you could not be logged in at this time please try again</p>";
    }
}


<div id='rightColumn'>
            <div id='title'>
                <h1>Attendance</h1>
            </div>
            <div id='content'>
                <form action="``<?php echo $_SERVER['PHP_SELF']; ?>?p=login" method='post'>
                <label>Username: <input type='text' name='name' id='name' /></label><br />
                <label>Password:  <input type='password' name='pass' id='pass' /></label><br />
                <input type='submit' id='submit' value='Login' />
                </form>
            </div>
        </div>
    </body>
</html>

Answer 1

如评论中所述，错误消息非常自我解释。显然header.php正在开始输出。你应该追踪它并弄清楚原因。解决方法是使用输出缓冲：

ob_start();
include('header.php');
...
ob_end_flush();
?>

这将阻止在调用flush函数之前发送任何输出; Documenation

关于$_SERVER['PHP_SELF']：你不应该编辑超级全局。在这种情况下，您所追求的信息使用不同的索引：$_SERVER['REQUEST_URI']

Answer 2

您可以尝试将第42行更改为：

header("Location: $_SERVER[PHP_SELF]",TRUE,302);

在解析html之前，重定向到新页面并使用sendcookies。

我建议使用ob_start并结束，但是：

ob_start();
//your html
$content = ob_get_contents();
ob_end_clean();

在那里找到更多信息 http://php.net/manual/pt_BR/function.ob-start.php

无法使用MySQL和PHP修改标头信息

2 个答案: