窗口顶部滚动时如何使用粘性侧栏向上移动

Question

粘边栏，只有坚持在侧边栏底部在窗口底部的我得到这个网站（ 得自举粘例子 ）

JavaScript的

$(function() {
    var win = $(window);
    var doc = $(document);
    var wh = win.height();
    var dh = doc.height();
    var sidebar = $('.rightside .stickybar');
    var sot = sidebar.offset().top;
    var sh = sidebar.height();
    var elementToBottom = dh - sot - sh;
    // reset the sidebar width
     var wt = sidebar.width();
     sidebar.width(wt);
    win.scroll(function(){
    var dst = doc.scrollTop();
    var scrollBottom = dh - dst - wh;
   if(scrollBottom <= elementToBottom) {
      sidebar.addClass('fixToBottom');
  } else {
     sidebar.removeClass('fixToBottom');
    }
   });
});

CSS

 .fixToTop {
   position: fixed;
   top: 50px;
  }
 .fixToBottom {
    bottom: 60px;
    position: fixed;
 }

HTML

   <header> </header>
     <div class="contents">
        <div class = "leftside"> left</div>
            < div class="righside">
           <div class="stickybar">
              // when move scrolling up and down 
            </div>
         </div> 
       </div>
      <footer> footer </div>

我有2列的布局。 左列比边栏更长。 我只希望边栏在底部到达浏览器窗口底部时才粘住。 因此，用户可以在滚动右侧栏的同时继续向下滚动左列的内容。 我在这里看到了很多棘手的问题，但是这种特殊情况仍然让我感到困惑。 我在左列上也有一个粘贴的标题栏，我已经成功粘贴了。

Answer 1

看看这个例子，我打了个电话。

http://www.bootply.com/hVx29SmQ4g

如果您或任何人有任何疑问，请给我发消息，我会尽力解释。 但是我注释了代码，因此应该很简单。 我希望它是您所需要的！

---

：：：码：：：

/*
===  JS  ===
============
Author:  Kevin Leegsma
Updated: Feb 10, 2015
Notes:   Coded for Stack Overflow - re: Sticky Sidebar
*/

/* Base function that waits till rest of site loads and then executes */
$(document).ready(function () {
    "use strict";

    /* activate sidebar, this can also be done as in-line HTML using the following line, instead of the Javascript below */
    /*  <div class = "col-xs-4" id = "rightColumn" data-spy = "affix" data-offset-bottom = "200">  */
    $('#sidebar').affix({
        offset: {
            top: 400  /* both TOP and BOTTOM can be used here, tweek to your own needs */
        }
    });

    /*This function gets the WIDTH of the wrapper and maintains it for the SIDEBAR*/
    /*It does this by setting the WRAPPER as the PARENT, it then calls a function to resize the child (SIDEBAR) 
    in this case equal to the parent size.*/
        /*NOTE: Without this function, the AFFIX still works, just doesn't function as nicely as it doesn't follow
        standard Bootstrap grid CSS rules.  */
    $('#sidebar').each(function () {
        var elem = $(this);
        var parentWrapper = $('#sidebarWrapper');
        var childToParentResize = function () {
            var sidebarWidth = $(parentWrapper).width();
            elem.width(sidebarWidth);
        };      
        childToParentResize();
        $(window).resize(childToParentResize);
    });

    /* Alert to inform you the SIDEBAR has become fixed, can be removed/commented, just for testing, but helpful for those new to AFFIX */  
    $('#sidebar').on('affixed.bs.affix', function(){
        alert("The left navigation menu has been affixed. Now it doesn't scroll with the page.");
    });
});



/* CSS used here will be applied after bootstrap.css
===  CSS  ===
=============
Author:  Kevin Leegsma
Updated: Feb 10, 2015
Notes:   Coded for Stack Overflow - re: Sticky Sidebar

--------------------------------------
Layout
-------------------------------------- */
/* Targets the SIDEBAR once the affix has become active */
/* Adjust these to cater to your layout settings */ 
#sidebar.affix{
    top: 10px;
    right: 8.5%;
}



/*
==============
===  HTML  ===
==============
Author:  Kevin Leegsma
Updated: February 10, 2015
Notes:   Coded for Stack Overflow - re: how-use-sticky-sidebar-move-up-when-window-scroll-top
*/
<!-- Main Code -->
<div class="container" id="main">
  <!-- Left column with dummy text -->
  <div class="col-xs-8" id="leftColumn">
    <h1> LEFT COLUMN</h1>
    <h3>With Even More Filler Text!</h3>
    <p>...a bunch of text...</p>
  </div><!--end leftColumn-->

  <!-- Right column/sidebar that affixes itself as the window is scrolled -->
  <!-- Stuck within a col-xs-4 parent element, this is because the AFFIX 
has wonky width controls, they ignore Bootstrap grids and aren't responsive
with this wrapper and the JS however, it resizes well. --> 
  <div class="col-xs-4" id="sidebarWrapper">
    <div id="sidebar" data-spy="affix">
      <h1> SIDEBAR</h1>
      <h3>With Filler!</h3>
      <small>
        <p>...sidebar text/links...</p>
      </small>
    </div><!--end sidebar-->
  </div><!--end sidebarWrapper-->
</div><!--end container-->

Answer 2

我现在不在家里的电脑上，如果今晚仍无法解决问题，我将举个例子。 但是，如果我正确地阅读了您需要的内容，那么您所要做的就是通过HTML / CSS给出一个要固定的元素AFFIX属性

<div id="sidebar" data-spy="affix" data-affix-bottom="50">

注意-> data-affix-bottom是一个偏移量，因此请对其进行调整以满足您的需要

或通过JavaScript $（“＃sidebar”）。affix（{offset：{bottom：someValue}}}）;

一些有用的链接对其进行了更深入的说明： http : //getbootstrap.com/javascript/#affix和http://goo.gl/8knwd4 （带有滚动边栏示例）