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问题:

jQuery's scrollTop returns null when window is an iframe. Has anyone been able to figure out how to get scrollTop of an iframe?

more info:

my script is running in the iframe itself, the parent window is on another domain, so I can't access the ID of the iframe or anything like that

回答1:

You can set scrollTop by using this setup:

$("html,body").scrollTop(25);

So you could try getting it like this:

$("html,body").scrollTop();

Because different browsers set the scrollTop on different elements (body or html).

From the scrollTo plugin:

But that will probably still fail in certain browsers. Here is the relevant section from the source code of Ariel Flesher's scrollTo plugin for jQuery:

// Hack, hack, hack :)
// Returns the real elements to scroll (supports window/iframes, documents and regular nodes)
$.fn._scrollable = function(){
  return this.map(function(){
    var elem = this,
      isWin = !elem.nodeName || $.inArray( elem.nodeName.toLowerCase(), ['iframe','#document','html','body'] ) != -1;

    if( ! isWin ) {
      return elem;
    }


    var doc = (elem.contentWindow || elem).document || elem.ownerDocument || elem;

     return $.browser.safari || doc.compatMode == 'BackCompat' ?
       doc.body : 
       doc.documentElement;
  });
};

You may then run:

$(window)._scrollable().scrollTop();

To determine how far the iframe has scrolled down.

回答2:

$('#myIframe').contents().scrollTop()

回答3:

I found this question while trying to SET scrollTop inside an iframe... not exactly your question (you wanted to GET) but here's a solution inside iframes for people that also end up here trying to SET.

If you want to scroll to the top of the page this will NOT work inside an iframe:

$("html,body").scrollTop(0);

However, this will work:

document.getElementById("wrapper").scrollIntoView();

Or the equivilent with jQuery:

 $("#wrapper")[0].scrollIntoView();

For this markup (contained inside an iframe):

<html>
  <body>
    <div id="wrapper">
      <!-- lots of content -->
    </div>
  </body>
</html>

回答4:

Good old javascript:

scrollTop = document.getElementById(IFRAME_ID).contentWindow.document.body.scrollTop;

回答5:

$('#myIframe').contents().scrollTop(0);

Only works with "0" as parameter

回答6:

or use this one

sample.showLoader = function() {
// show cursor wait
document.getElementsByTagName('body')[0].style.cursor = 'wait';
var loader = $('#statusloader');
// check if we're runnign within an iframe
var isIframe = top !== self;
if (isIframe) {
    var topPos = top.pageYOffset + 300;
    // show up loader in middle of the screen
    loader.show().css({
        top : topPos,
        left : '50%'
    });
} else {
    // show up loader in middle of the screen
    loader.show().css({
        top : '50%',
        left : '50%'
    });
}
};

回答7:

I know I'm late to the game here, but I was trying to figure this out for a long list on mobile. scrollTop() wasn't working for me due to cross-domain conflicts(and I didn't have access to parent window), but changing the height did:

$('#someClickableElementInIFrame').on('click', function(e){
      $("html body").animate({
      'height' : "0"
    }, {
        complete: function(){
          $("html body").css({
            'height' : "auto"
            })
          }
      })
});

回答8:

I have try to

$('#myIframe').contents().scrollTop(0);

and

 let scrollTop = document.getElementById(IFRAME_ID).contentWindow.document.body.scrollTop;

the first function work success in desktop browser. not working in mobile browser. so I use another function with scrollIntoView

$("#ButtonId").click(function() {
        var win = document.getElementById(IFRAMEID).contentWindow;
        var scrollTop = win.document.documentElement.scrollTop || win.pageYOffset || win.document.body.scrollTop;
        // scrollTop can getted
        if (scrollTop) {
            win.document.documentElement.scrollTop = 0;
            win.pageYOffset = 0; // safari
            win.document.body.scrollTop = 0;
        } else {
            win.document.body.scrollIntoView(true); // let scroll to the target view 
        }
    });

scrollIntoView() view in scrollIntoView - MDN