Overflow of sidebar with Twitter Bootstrap Affix [

问题:

I'm trying to use the affix plugin by twitter bootstrap but I can't figure out how to constrain it within the parent container, i've created the following example to show my problem:

Problem demo: http://www.codeply.com/go/DvcRXkeFZa

<div class="container">
    <div class="row">
        <div class="col-md-3 column">
            <ul id="sidebar" class="well nav nav-stacked" data-spy="affix" data-offset-top="130">
                <li><a href="#software"><b>Software</b></a></li>
                <li><a href="#features">Features</a></li>
                <li><a href="#benefits">Benefits</a></li>
                <li><a href="#costs">Costs</a></li>
            </ul>
        </div>
        <div class="col-md-9 column">
            <h1>Blah, blah, blah</h1>
            <hr>
            <a class="anchor3" id="top" name="software"></a>
            <p>
             content here that scrolls...
            </p>
        </div>
    </div>
</div>

As you can see when you scroll it overflows out of the sidebar, it also doesn't affix to the bottom of the page when it reaches the bottom.

回答1:

From the Bootstrap docs (http://getbootstrap.com/2.3.2/javascript.html#affix)..

Heads up! You must manage the position of a pinned element and the behavior of its immediate parent. Position is controlled by affix, affix-top, and affix-bottom. Remember to check for a potentially collapsed parent when the affix kicks in as it's removing content from the normal flow of the page.

So you need some CSS for affix to set the width for the element when it becomes fixed. Such as:

#sidebar.affix {
    position: fixed;
    top: 0;
    width:225px;
  }

Demo on Bootply: http://bootply.com/73864

Related answers on Bootstrap affix:
How to create a sticky left sidebar menu using bootstrap 3?
Twitter-bootstrap 3 affixed sidebar overlapping content when window resized and also footer

回答2:

In an answer to @FreezeDriedPop I found this to work for me:

var navbw = $('#sidebar').width()-7;
$('header').append('<style id="addedCSS" type="text/css">#sidebar.affix {width:'+navbw+'px;}</style>');