​x
 
<!DOCTYPE html>
<html>
<body>
​
<h3>如何访问 IFRAME 元素的演示</h3>
​
<iframe id="myFrame" src="/index.html"></iframe>
​
<p>单击按钮以获取 iframe 的 URL。</p>
​
<button onclick="myFunction()">试一试</button>
​
<p id="demo"></p>
​
<script>
function myFunction() {
  var x = document.getElementById("myFrame").src;
  document.getElementById("demo").innerHTML = x;
}
</script>
​
</body>
</html>
​
​