如何利用JavaScript的Presentation API实现多屏展示？

if ('presentation' in navigator) {
  console.log('Presentation API 可用');
} else {
  console.log('当前浏览器不支持 Presentation API');
}

async function startPresentation() {
  try {
    const session = await navigator.presentation.requestSession({
      url: 'https://yourdomain.com/presentation.html'
    });
    
    // 监听会话状态变化
    session.onstatechange = () => {
      console.log('会话状态:', session.state);
    };

    // 接收来自展示页的消息
    session.onmessage = (event) => {
      console.log('收到消息:', event.data);
    };

    return session;
  } catch (err) {
    console.error('无法启动展示:', err);
  }
}

session.send('next'); // 发送“下一页”指令
session.send(JSON.stringify({ action: 'goto', slide: 5 }));

// 在 presentation.html 中
navigator.presentation.receiver.connectionList.then(connections => {
  connections[0].onmessage = (event) => {
    const data = event.data;
    if (data === 'next') {
      showNextSlide();
    }
  };
});

session.onstatechange = () => {
  if (session.state === 'disconnected') {
    console.log('展示已断开');
    // 可提示用户重新连接或清理资源
  }
};