Stacking Divs from Bottom to Top

问题:

When appending divs to a div with a fixed height, the child divs will appear from top to bottom, sticking at the top border.

┌─────────────────────────┐
│ Child Div 1             │
│ Child Div 2             │
│                         │
│                         │
│                         │
└─────────────────────────┘

I'm now trying to display them from bottom to top like this (sticking to the bottom border):

┌─────────────────────────┐
│                         │
│                         │
│                         │
│ Child Div 1             │
│ Child Div 2             │
└─────────────────────────┘
┌─────────────────────────┐
│                         │
│                         │
│ Child Div 1             │
│ Child Div 2             │
│ Child Div 3             │
└─────────────────────────┘
┌───────────────────────┬─┐
│ Child Div 2           │▲│
│ Child Div 3           │ │
│ Child Div 4           │ │
│ Child Div 5           │█│
│ Child Div 6           │▼│
└───────────────────────┴─┘

And so on... I hope you get what I mean.

Is this simply doable with CSS (something like vertical-align: bottom)? Or do I have to hack something together with JavaScript?

回答1:

All the answers miss the scrollbar point of your question. And it's a tough one. If you only need this to work for modern browsers and IE 8+ you can use table positioning, vertical-align:bottom and max-height. See MDN for specific browser compatibility.

Demo (vertical-align)

.wrapper {
  display: table-cell;
  vertical-align: bottom;
  height: 200px;
}
.content {
  max-height: 200px;
  overflow: auto;
}

html

<div class="wrapper">
  <div class="content">
     <div>row 1</div>
     <div>row 2</div>
     <div>row 3</div>  
  </div>
</div>  

---

Other than that, I think it's not possible with CSS only. You can make elements stick to the bottom of their container with position:absolute, but it'll take them out of the flow. As a result they won't stretch and make the container to be scrollable.

Demo (position-absolute)

.wrapper {
  position: relative;
  height: 200px;
}
.content {
  position: absolute;
  bottom: 0;
  width: 100%;
}

回答2:

A more modern answer to this would be to use flexbox.

As with many other modern features, they won't work in legacy browsers, so unless you're ready to ditch support for browsers from the IE8-9 era you will need to look for another method.

Here's how it's done:

.parent {
  display: flex;
  justify-content: flex-end;
  flex-direction: column;
}

.child {
  /* whatever */
}

And that's all you need. For further reading on flexbox, see MDN.

Here's an example of this with some basic styling: http://codepen.io/Mest/pen/Gnbfk

回答3:

Keepin' it oldskool...

I wanted to do the same thing in a #header div so I created an empty div called #headspace and placed it on the top the stack (inside of #header):

<div id="header">
    <div id="headspace"></div>
    <div id="one">some content</div>
    <div id="two">other content</div>
    <div id="three">more content</div>
</div> <!-- header -->

Then I used a percentage, for the height of the invisible #headspace div, to push the others down. It's easy to use the developer / inspector tools of the browser to get this just right.

#header {
    width: 100%;
    height: 10rem;
    overflow: auto;
}

#headspace {
    width: 100%;
    height: 42%;    /* Experiment with Inspect (Element) tool */
}

#one, #two, #three {
    /* Insert appropriate dimensions for others... */
}

回答4:

This is simple when you use position: absolute.

http://jsfiddle.net/XHeZj/

回答5:

<div style="height: 500px;">
    <div style="height: 20px; position: absolute; bottom: 120px;">Child Div 1</div>
    <div style="height: 20px; position: absolute; bottom: 100px;">Child Div 2</div>
    <div style="height: 20px; position: absolute; bottom: 80px;">Child Div 3</div>
    <div style="height: 20px; position: absolute; bottom: 60px;">Child Div 4</div>
    <div style="height: 20px; position: absolute; bottom: 40px;">Child Div 5</div>
</div>