js动态改变iframe高度

<iframe id="myIframe" src="content.html" frameborder="0"></iframe>

function resizeIframe(obj) {
  obj.style.height = obj.contentWindow.document.documentElement.scrollHeight + 'px';
}

window.onload = function() {
  var iframe = document.getElementById('myIframe');
  resizeIframe(iframe);
};

window.onload = function() {
  var iframe = document.getElementById('myIframe');
  iframe.onload = function() {
    iframe.contentWindow.postMessage('getHeight', 'https://target-domain.com');
  };
  window.addEventListener('message', function(event) {
    if (event.origin !== 'https://target-domain.com') return; // 安全检查
    iframe.style.height = event.data + 'px';
  }, false);
};

window.addEventListener('message', function(event) {
  if (event.origin !== 'https://parent-domain.com') return; // 安全检查
  if (event.data === 'getHeight') {
    var height = document.documentElement.scrollHeight;
    event.source.postMessage(height, event.origin);
  }
}, false);