<font color="#0000CC">示例：獲取指定時(shí)間段的彈幕</font>
```php
// get_danmu.php
$time = $_GET['time'] ?? 0;
$range = 5; // 前后5秒

$stmt = $pdo->prepare("SELECT content, color, video_time FROM danmu WHERE video_time BETWEEN ? AND ?");
$stmt->execute([$time - $range, $time + $range]);

$danmus = $stmt->fetchAll(PDO::FETCH_ASSOC);
echo json_encode($danmus);

<p>運(yùn)行命令：<code>php server.php</code></p>

<H3>4. 前端集成彈幕與實(shí)時(shí)通信</H3>
<p>前端使用 WebSocket 連接 Swoole 服務(wù)，并在視頻播放時(shí)動(dòng)態(tài)顯示彈幕。</p>
```html
<video id="player" src="demo.mp4" controls width="800"></video>
<div id="danmu-container" style="position:relative; width:800px; height:450px;"></div>

<script>
const player = document.getElementById('player');
const container = document.getElementById('danmu-container');

// WebSocket 連接實(shí)時(shí)彈幕
const ws = new WebSocket('ws://your-server-ip:9502');
ws.onmessage = function(event) {
    showDanmu(event.data);
};

// 發(fā)送彈幕
function sendDanmu() {
    const input = prompt("輸入彈幕：");
    if (input) {
        ws.send(JSON.stringify({
            content: input,
            time: player.currentTime,
            color: 'yellow'
        }));

        // 同時(shí)保存到服務(wù)器（可選）
        fetch('save_danmu.php', {
            method: 'POST',
            body: JSON.stringify({
                content: input,
                time: player.currentTime,
                color: 'yellow'
            })
        });
    }
}

// 顯示彈幕
function showDanmu(msg) {
    const data = typeof msg === 'string' ? JSON.parse(msg) : msg;
    const d = document.createElement('div');
    d.style.cssText = `
        position:absolute; left:100%; top:${Math.random() * 200}px;
        color:${data.color}; white-space:nowrap; 
        animation: move 8s linear;
    `;
    d.innerText = data.content;
    container.appendChild(d);

    setTimeout(() => d.remove(), 8000);
}

// 綁定快捷鍵發(fā)送
player.addEventListener('click', sendDanmu);
</script>

<style>
@keyframes move {
    from { transform: translateX(0); }
    to   { transform: translateX(-100%); }
}
#danmu-container { pointer-events: none; }
</style>