使用jQuery可以比较文档高度，scrollTop位置和视口高度，这可能会让您得到所需的答案。

以下行：

  $（window）.scroll（function（）{
 if（isMyStuffScrolling（））{
 //这里有一个滚动条！
} 
}）; 

函数isMyStuffScrolling（）{
 var docHeight = $（document）.height（）; 
 var scroll = $（window）.height（）+ $（window）.scrollTop（）; 
 return（docHeight == scroll）; 
} 
 

How can I detect a Scrollbar presence ( using Javascript ) in HTML iFrame ?

I have already tried :

        var vHeight = 0;
        if (document.all) {
          if (document.documentElement) {
            vHeight = document.documentElement.clientHeight;
          } else {
            vHeight = document.body.clientHeight
          }
    } else {
      vHeight = window.innerHeight;
    }

    if (document.body.offsetHeight > vHeight) {
      //when theres a scrollbar
    }else{
      //when theres not a scrollbar
    }

And I also had tried :

           this.scrollLeft=1;
    if (this.scrollLeft>0) {
        //when theres a scrollbar
        this.scrollLeft=0;
        }else{
        //when theres not a scrollbar
        return false;
    }

With no success..

I have searched the javascript objets on DOM Inspector, but didn't find anything.

Is is possible to detect a scrollbar presence in a iframe in javacscript ?

---

The iframe content comes from the same domain.

No success until now..

alt text http://www.upvtp.com.br/file.php/1/help_key.jpg

Using jQuery you can compare the document height, the scrollTop position and the viewport height, which might get you the answer you require.

Something along the lines of:

$(window).scroll(function(){
  if(isMyStuffScrolling()){
    //There is a scroll bar here!
  }
}); 

function isMyStuffScrolling() {
  var docHeight = $(document).height();
  var scroll    = $(window).height() + $(window).scrollTop();
  return (docHeight == scroll);
}