多个二级域名iframe

// 示例：使用CORS
// 服务器端设置响应头
Access-Control-Allow-Origin: https://example.com

// 示例：延迟加载iframe
function loadIframe(src, id) {
  const iframe = document.createElement('iframe');
  iframe.src = src;
  iframe.id = id;
  document.body.appendChild(iframe);
}

window.addEventListener('scroll', () => {
  const iframes = document.querySelectorAll('iframe');
  iframes.forEach(iframe => {
    if (isInViewport(iframe)) {
      loadIframe(iframe.src, iframe.id);
    }
  });
});

function isInViewport(element) {
  const rect = element.getBoundingClientRect();
  return (
    rect.top >= 0 &&
    rect.left >= 0 &&
    rect.bottom <= (window.innerHeight || document.documentElement.clientHeight) &&
    rect.right <= (window.innerWidth || document.documentElement.clientWidth)
  );
}

<!-- 示例：使用sandbox属性 -->
<iframe src="https://example.com" sandbox="allow-scripts allow-same-origin"></iframe>