这是一个使用php、mysql、html、css和javascript的简单聊天系统的代码。这段代码的问题是，每当用户输入一条消息并按下send按钮时，消息就会被发送，并且值会被插入到消息表中，但是当我们刷新页面时，同样的消息会再次出现，并且消息会再次被插入到数据库中。我试过管理架构，但问题没有解决。这是我的密码。
<html>
<head>
<link rel="stylesheet" type="text/css" href="chat.css">
</link>
</head>
<body>
<?php
session_start();
include 'ConnectionPDO.php';
//include_once 'chat.html';
$_SESSION["person"]=$_GET["person"];
if(isset($_SESSION['username'])){
if(isset($_POST['btn'])){
$message=$_POST['msg'];
$person=$_GET['person'];
try {
$stmt = $dbh->prepare("INSERT INTO `messages` (`id`, `sendby`, `sento`, `date/time`, `seen`, `active`, `message`) VALUES (NULL, ?, ?, CURRENT_TIMESTAMP, 'No', 'No', ?)");
$stmt->bindParam(1,$_SESSION['username']);
$stmt->bindParam(2,$person);
$stmt->bindParam(3,$message);
$stmt->execute();
if($stmt) {
echo "<br>";
echo "Message sent!";
}
}
catch (PDOException $e) {
echo $e->getMessage();
}
}
}else{
}
?>
<div id="main">
<div id="inbox" style="height:400px;overflow:scroll">
<?php
$_SESSION["person"]=$_GET["person"];
try {
$stmt2 = $dbh->prepare("select * from `messages` where (`sendby`=? AND `sento`=?) OR (`sendby`=? AND `sento`=?)");
$stmt2->bindParam(1, $_SESSION['username']);
$stmt2->bindParam(2, $_SESSION["person"]);
$stmt2->bindParam(3, $_SESSION["person"]);
$stmt2->bindParam(4, $_SESSION['username']);
$stmt2->execute();
while($row=$stmt2->fetch()) {
$sento= $row['sendby'];
$message= $row['message'];
$time= $row['date/time'];
echo $sento;
echo "<br>";
echo $message;
echo "<br>";
echo $time;
echo "<br>";
echo "<hr>";
}
}
catch (PDOException $e) {
echo $e->getMessage();
}
?>
</div>
<form method="post">
<input type="text" name="msg" placeholder="Enter your message here" id="msg"><br>
<input type="submit" value="Send" name="btn" id="btn">
</form>
</div>
<script>
setInterval(myFunction,1000);
function myFunction(){
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function()
{
if (this.readyState == 4 && this.status == 200) {
document.getElementById("inbox").innerHTML = this.responseText;
}
};
xhttp.open("POST","sendMsg.php", true);
xhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xhttp.send();
}
</script>
</body>
</html>
1条答案
按热度按时间jmo0nnb31#
当前端（html、css）和后端（php和mysql/pdo查询）位于同一页面上时，就会发生这种情况。更好的是，您可以使用前端插入详细信息并将其发送到其他php文件中的后端，并通过ajax/header/cookies等将结果状态重定向到前端文件。