Question

我已经创建了php在线聊天。

这是我的index.php：

<?php
session_start();
function loginForm(){
    echo'
    <div id="loginform">
    <form action="index.php" method="post">
        <p>Please enter your name to continue:</p>
        <label for="name">Name:</label>
        <input type="text" name="name" id="name" />
        <input type="submit" name="enter" id="enter" value="Enter" />
    </form>
    </div>
    ';
}

if(isset($_POST['enter'])){
    if($_POST['name'] != ""){
        $_SESSION['name'] = stripslashes(htmlspecialchars($_POST['name']));
    }
    else{
        echo '<span class="error">Please type in a name</span>';
    }
}
?>

<!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>
<title>Chat</title>
<link type="text/css" rel="stylesheet" href="style.css" />
</head>



<?php
if(!isset($_SESSION['name'])){
    loginForm();
}
else{
?>
<div id="wrapper">
    <div id="menu">
        <p class="welcome">Welcome, <b><?php echo $_SESSION['name']; ?></b></p>
        <p class="logout"><a id="exit" href="#">Exit Chat</a></p>
        <div style="clear:both"></div>
    </div>    
    <div id="chatbox"></div>

    <form name="message" action="">
        <input name="usermsg" type="text" id="usermsg" size="63" />
        <input name="submitmsg" type="submit"  id="submitmsg" value="Send" />
    </form>
</div>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3/jquery.min.js"></script>
<script type="text/javascript">
// jQuery Document
$(document).ready(function(){
    //If user submits the form
    $("#submitmsg").click(function(){   
        var clientmsg = $("#usermsg").val();
        $.post("post.php", {text: clientmsg});              
        $("#usermsg").attr("value", "");
        return false;
    });

    //Load the file containing the chat log
    function loadLog(){     

        $.ajax({
            url: "log.html",
            cache: false,
            success: function(html){        
                $("#chatbox").html(html); //Insert chat log into the #chatbox div               
            },
        });
    }

    //Load the file containing the chat log
    function loadLog(){     
        var oldscrollHeight = $("#chatbox").attr("scrollHeight") - 20; //Scroll height before the request
        $.ajax({
            url: "log.html",
            cache: false,
            success: function(html){        
                $("#chatbox").html(html); //Insert chat log into the #chatbox div   

                //Auto-scroll           
                var newscrollHeight = $("#chatbox").attr("scrollHeight") - 20; //Scroll height after the request
                if(newscrollHeight > oldscrollHeight){
                    $("#chatbox").animate({ scrollTop: newscrollHeight }, 'normal'); //Autoscroll to bottom of div
                }               
            },
        });
    }

    setInterval (loadLog, 2500);    //Reload file every 2500 ms or x ms if you w
});
</script>
<?php
}
?>
<script type="text/javascript">
// jQuery Document
$(document).ready(function(){
    //If user wants to end session
    $("#exit").click(function(){
        var exit = confirm("Are you sure you want to end the session?");
        if(exit==true){window.location = 'index.php?logout=true';}      
    });
});
</script>
<?php 
if(isset($_GET['logout'])){ 

    //Simple exit message
    $fp = fopen("log.html", 'a');
    fwrite($fp, "<div class='msgln'><i>User ". $_SESSION['name'] ." has left the chat session.</i><br></div>");
    fclose($fp);

    session_destroy();
    header("Location: index.php"); //Redirect the user
}
?>

</body>
</html>

当我运行上面的代码时，我得到了这样的警告，

警告：session_start（）[function.session-start]：无法发送会话缓存限制器 - 已发送的标头（输出从C：\ xampp \ htdocs \ selva \ php \ onlinechat \ chat \ index.php：1开始）在第2行的C：\ xampp \ htdocs \ selva \ php \ onlinechat \ chat \ index.php

我跟踪了所有其他stackoverlfow资源并修改了一些更改。

但仍然显示上述警告。

任何人都可以帮我解决这个问题吗？

感谢。

Answer 1

您需要在第一个脚本中打开session_start()标记之后直接调用<?php，此脚本之前没有任何空格，并且在输出任何其他信息之前/之后将其发送到浏览器。

<?php
session_start();
//... everything else

Answer 2

在打开标记之后直接使用session_start（），然后输出任何其他信息/发送到浏览器。

警告：session_start（）[function.session-start]：无法发送会话缓存限制器 - 已发送的标头（输出在php中启动）

2 个答案: