可能重复：
Cannot send session cookie - headers already sent
Headers already sent by PHP
不知何故，我的网站决定打破，所以确实如此。 artfulme.net（我的网站）不知怎的错误......
警告：session_start（）[function.session-start]：无法发送会话cookie - 已在/ home / artfulme中发送的文件（输出从/home/artfulme/public_html/index.php:1开始）第1行/public_html/index.php
警告：session_start（）[function.session-start]：无法发送会话缓存限制器 - 已在/ home / artfulme中发送的标头（输出从/home/artfulme/public_html/index.php:1开始）第1行/public_html/index.php
我不知道发生了什么。我正在露营，当我回来时，每次去我的网站都会收到这个错误。
这是我的完整页面代码：
<?php session_start(); $_SESSION['loginreturn']="../index.php";
include("scripts/mysql.php");?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<!-- Website Stuff -->
<title>artfulME</title>
<link rel="shortcut icon" href="images/favicon.ico" />
<!-- CSS Stuff -->
<style type="text/css">
body,td,th {
font-family: Arial, Helvetica, sans-serif;
font-size: 16px;
font-weight: lighter;
color: #FFFFFF;
}
a:link {
color: #6F8C37;
text-decoration: none;
}
a:visited {
text-decoration: none;
color: #526828;
}
a:hover {
text-decoration: underline;
color: #ABC974;
}
a:active {
text-decoration: none;
}
body {
background-color: #7b7b7b;
}
</style>
<link href="css/index.css" rel="stylesheet" type="text/css" />
<link href="css/login.css" rel="stylesheet" type="text/css" />
<!-- Script Stuff -->
<script type="text/javascript">
function MM_preloadImages() { //v3.0
var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}
function MM_swapImgRestore() { //v3.0
var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}
function MM_findObj(n, d) { //v4.01
var p,i,x; if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
if(!x && d.getElementById) x=d.getElementById(n); return x;
}
function MM_swapImage() { //v3.0
var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}
function showElement(obj){
document.getElementById(obj).style.display="block";
}
function hideElement(obj){
document.getElementById(obj).style.display="none";
}
function restoreValue(obj){
if(obj.value == ""){
obj.value = obj.defaultValue;
}
}
function clearValue(obj){
if(obj.value == obj.defaultValue){
obj.value = "";
}
}
function changeTypeToPass(obj){
if(obj.value != obj.defaultValue){
obj.type = "password";
}
}
function changeTypeToText(obj){
if(obj.value == obj.defaultValue){
obj.type = "text";
}
}
</script>
</head>
<body onload="MM_preloadImages('images/navi/homeover.png','images/navi/blogover.png','images/navi/mediaover.png','images/navi/blogover.PNG','images/navi/contactover.PNG')">
<div id="wrapper">
<p style="text-align: right; text-shadow: 1px 1px #000; height: 20px; margin-right: 3px">
<?php
if(!isset($_SESSION['loggedin'])){
echo "<a href='javascript:void(0);' id='showLogin' onclick=\"showElement('login');\">Login</a>\n";
}else{
if($_SESSION['username'] == "artfulME" || $_SESSION['username'] == "Admin"){
echo "<strong>Hello</strong> <a href='user/index.php'>".$_SESSION['username']."</a>! <a href='post/index.php'>Post</a> | <a href='userslist/index.php'>View Users List</a> | <a href='upload/index.php'>Upload</a> | <a onclick='document.logoutform.submit(); return false;' href='javascript:void(0);'>Logout</a><form style='display:none' id='logoutform' name='logoutform' action='scripts/logout.php'></form>";
$_SESSION['accesstoadmin'] = 1;
}else{
echo "<strong>Hello</strong> <a href='user/index.php'>".$_SESSION['username']."</a>! <a onclick='document.logoutform.submit(); return false;' href='javascript:void(0);'>Logout</a><form style='display:none' id='logoutform' name='logoutform' action='scripts/logout.php'></form>";
}
}
?></p>
<div id="login">
<span style="text-align: right"><p><img src="images/logintop.png" width="31" height="15" alt="logintop" /></p></span>
<div id="cont1">
<div style="height:5px"></div>
<div id="cont2">
<form id="loginform" name="loginform" method="post" action="scripts/login.php">
<table width="100%" border="0" cellspacing="2" cellpadding="0">
<tr>
<td><input name="entlogin" type="text" id="entlogin" onfocus="clearValue(this);" onblur="restoreValue(this);" value="Username or Email" maxlength="50" /></td>
</tr>
<tr>
<td><input name="entpass" type="text" id="entpass" onfocus="clearValue(this); changeTypeToPass(this);" onblur="restoreValue(this); changeTypeToText(this);" value="Password" maxlength="15" /></td>
</tr>
<tr>
<td><a href="javascript:void(0);" onclick="document.loginform.submit(); return false;">Continue</a> or <a href="signup/index.php">Signup!</a></td>
</tr>
<tr>
<td> <a href="javascript:void(0);"></a><a href="javascript:void(0);" onclick="hideElement('login');">Close</a></td>
</tr>
</table>
</form>
</div>
<div style="height:5px"></div>
</div>
</div>
<div id="header"><img src="images/logo.png" alt="artfulME" width="500" height="143" border="0" usemap="#Map" />
<map name="Map" id="Map" title="Home | artfulME">
<area shape="rect" coords="6,37,311,108" href="index.php" alt="Home | artfulME" />
</map>
</div>
<div id="navi">
<p><a href="index.php" onmouseout="MM_swapImgRestore()" onmouseover="MM_swapImage('HOME','','images/navi/homeover.png',1)"><img src="images/navi/home.png" alt="HOME" name="HOME" width="150" height="40" border="0" id="HOME" /></a><a href="blog/index.php" onmouseout="MM_swapImgRestore()" onmouseover="MM_swapImage('BLOG','','images/navi/blogover.PNG',1)"><img src="images/navi/blog.png" alt="BLOG" name="BLOG" width="145" height="40" border="0" id="BLOG" /></a><a href="media/index.php" onmouseout="MM_swapImgRestore()" onmouseover="MM_swapImage('MEDIA','','images/navi/mediaover.PNG',1)"><img src="images/navi/media.png" alt="MEDIA" name="MEDIA" width="156" height="40" border="0" id="MEDIA" /></a><a href="contact/index.php" onmouseout="MM_swapImgRestore()" onmouseover="MM_swapImage('CONTACT','','images/navi/contactover.PNG',1)"><img src="images/navi/contact.png" alt="CONTACT" name="CONTACT" width="205" height="40" border="0" id="CONTACT" /></a></p>
</div>
<div id="left">
<div id="block1">
<div id="container">
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td width="50%"><h1>Video to be here soon!</h1></td>
</tr>
<tr>
<td><p><a href="javascript:void(0);" id="showAbout" onclick="hideElement('showAbout'); showElement('moreAbout');">More about me...</a></p>
<p id="moreAbout" style="display:none"><a href="#" onclick="showElement('showAbout'); hideElement('moreAbout');">Hide more about me...</a><br />
I'm not just your ordinary person. Most male humans my age play video games, watch Youtube, eat, and sleep. I do all of those things, but I bring them up a level. I make video games (sometimes), try my best at editing Youtube videos, and I eat a lot and sleep normally.<br />
Also, I'm a <em>very</em> good web-designer. This website is actually my best I'm sure... But, if you take a look at <a href="http://www.wildwestgraniteaz.com">www.wildwestgraniteaz.com</a> or <a href="http://villaingogh.x10.mx">villaingogh.x10.mx</a>, those are both my works.</p>
<p> </p></td>
</tr>
</table>
</div>
</div>
<div id="block3">
<div id="container">
<h1>Recent tweets...</h1>
<p>
<script src="http://widgets.twimg.com/j/2/widget.js"></script>
<script>
new TWTR.Widget({
version: 2,
type: 'profile',
rpp: 21,
interval: 6000,
width: 'auto',
height: 300,
theme: {
shell: {
background: '#282828',
color: '#707071'
},
tweets: {
background: '#282828',
color: '#ffffff',
links: '#708c37'
}
},
features: {
scrollbar: true,
loop: false,
live: false,
hashtags: true,
timestamp: true,
avatars: false,
behavior: 'all'
}
}).render().setUser('FethrdWlf').start();
</script>
</p>
</div>
</div>
</div>
<div id="right">
<div id="block2">
<div id="container">
<?php
if(isset($_SESSION['flagged'])){
echo $_SESSION['flagged'];
unset($_SESSION['flagged']);
}elseif(isset($_SESSION['notflagged'])){
echo $_SESSION['notflagged'];
unset($_SESSION['notflagged']);
}
?>
<h1>Most recent blog post...</h1>
<?php include("scripts/latestpost.php"); ?>
</div>
</div>
<div id="block4">
<div id="container">
<h1>My latest Youtube video:</h1>
<p>
<iframe style="margin-bottom: 5px;" width="434" height="277" src="http://www.youtube.com/embed/dUyAA_CT-S0" frameborder="0" allowfullscreen></iframe>
</p>
</div>
</div>
</div>
</div>
<div id="copyright" style="background-color:#7b7b7b">
<p style="font-size: 12px">2011 © artfulME, Johnny McNeil</p></div>
</body>
</html>
我真的不知道该怎么做。
答案 0 :(得分：1)
如果浏览器没有输出，PHP只能发送标头来设置会话cookie
您应该检查以确保php脚本开头确实没有空格。您还可以检查文件编码，这可能使php认为有非打印字符的输出（如果您的托管服务提供商升级了php或更改了默认编码，可能会发生这种情况）。
你可能想查看你的ftp日志，看看是否有人设法进入你的网站，如果你不知道这是怎么回事，那就改变一些。
答案 1 :(得分：1)
我也遇到过这个问题。我通过将会话放在我的编码之上来解决它，然后删除会话之间的所有空白区域以及与会话相关的编码。