Javascript MutationObserver 错误

Question

以下脚本有效，但 chrome 显示有错误..
我应该怎么做才能解决这个错误？

function Do(){alert("test");}

new MutationObserver(Do).observe(document.body,{childList:true,subtree:true}); //works, but there's error.

chrome控制台的错误信息是这样的；

Uncaught NotFoundError: An attempt was made to reference a Node in a context where it does not exist. (anonymous function)

Answer 1

chrome执行代码的时候还没有创建Node body。所以你可以这样改变你的代码:

    window.onload=function(){
      function Do(){alert("test");};
      new MutationObserver(Do).observe(document.body,{childList:true,subtree:true});
    };

或者用 jQuery 做:

    $(document).ready(function(){
    //your code
    });