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php实现双方聊天

2026-03-13 12:39:09PHP

实现 PHP 双方聊天功能

数据库设计

需要创建一张表存储聊天消息，字段包括发送者、接收者、消息内容和时间戳。

CREATE TABLE chat_messages (
    id INT AUTO_INCREMENT PRIMARY KEY,
    sender_id INT NOT NULL,
    receiver_id INT NOT NULL,
    message TEXT NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    is_read BOOLEAN DEFAULT FALSE
);

发送消息功能

创建一个PHP文件处理消息发送，例如send_message.php

<?php
// 连接数据库
$conn = new mysqli('localhost', 'username', 'password', 'database');

// 获取POST数据
$sender_id = $_POST['sender_id'];
$receiver_id = $_POST['receiver_id'];
$message = $_POST['message'];

// 插入消息到数据库
$stmt = $conn->prepare("INSERT INTO chat_messages (sender_id, receiver_id, message) VALUES (?, ?, ?)");
$stmt->bind_param("iis", $sender_id, $receiver_id, $message);
$stmt->execute();
?>

获取消息功能

创建get_messages.php获取聊天记录

<?php
header('Content-Type: application/json');

$conn = new mysqli('localhost', 'username', 'password', 'database');

$user1 = $_GET['user1'];
$user2 = $_GET['user2'];

$query = "SELECT * FROM chat_messages WHERE 
          (sender_id = ? AND receiver_id = ?) OR 
          (sender_id = ? AND receiver_id = ?) 
          ORDER BY created_at ASC";
$stmt = $conn->prepare($query);
$stmt->bind_param("iiii", $user1, $user2, $user2, $user1);
$stmt->execute();
$result = $stmt->get_result();

$messages = [];
while($row = $result->fetch_assoc()) {
    $messages[] = $row;
}

echo json_encode($messages);
?>

前端实现

创建聊天界面chat.html

<div id="chat-container">
    <div id="messages"></div>
    <input type="text" id="message-input">
    <button id="send-button">发送</button>
</div>

<script>
// 获取用户ID
const user1 = 1; // 当前用户ID
const user2 = 2; // 聊天对象ID

// 定期获取新消息
function fetchMessages() {
    fetch(`get_messages.php?user1=${user1}&user2=${user2}`)
        .then(response => response.json())
        .then(messages => {
            document.getElementById('messages').innerHTML = '';
            messages.forEach(msg => {
                const div = document.createElement('div');
                div.className = msg.sender_id == user1 ? 'sent' : 'received';
                div.textContent = msg.message;
                document.getElementById('messages').appendChild(div);
            });
        });
}

// 每2秒刷新一次消息
setInterval(fetchMessages, 2000);

// 发送消息
document.getElementById('send-button').addEventListener('click', () => {
    const message = document.getElementById('message-input').value;
    if(message.trim() === '') return;

    const formData = new FormData();
    formData.append('sender_id', user1);
    formData.append('receiver_id', user2);
    formData.append('message', message);

    fetch('send_message.php', {
        method: 'POST',
        body: formData
    }).then(() => {
        document.getElementById('message-input').value = '';
        fetchMessages();
    });
});
</script>