css以动态div为中心

Question

我有一个div #content，其中我在运行中添加左浮动的div #block并且div（a），＃lcontent和#rcontent两侧都有固定宽度的div 当side div具有动态高度和#content随时间变化时，我如何让#content保持在中心

内容应该保持在中心，其中有2,3,4或100 #block。但#block应始终位于#content

的左侧

只有#lcontent，＃rcontent和#block有固定的宽度

html代码

<div id="contentcontainer">
    <div id="lcontent"></div>
    <div id="mcontent">
        <div id="content">
            <div id="block"></div>
            <div id="block"></div>
            <div id="block"></div>
            <div id="Block"></div>
            <div id="Block"></div>
        </div>
    </div>
    <div id="rcontent"></div>
</div>

css代码

#lcontent
{
float: left;
width: 100px;
min-width: 100px;
min-height: 100px;
background: lightblue;   
}
#rcontent
{
float: right;
width: 100px;
background: lightblue;
}
#mcontent
{
background: lightgrey;
float: right;
right: 50%;
position: relative;
}
#content 
{
float: right;
right: -50%;
position: relative;
background: green;
min-height: 200px;
text-align: center;
}
#block
{
margin: 5px;
width: 300px;
border: 1px solid red;
display: inline-block;½ 
height: 150px;   
}

Answer 1

使用纯css会非常困难，需要你知道 容器将拥有的盒子数（并根据它添加一个类） - 如果这是动态内容，那么你应该有一个服务器端语言。您还需要很多媒体查询：

＆＃13;

＆＃13;

.container {
    text-align:center;
}
.centered {
    text-align:left;
    margin:auto;
}
.block {
    margin:3px;
    width:100px;
    height:100px;
    float:left;
    vertical-align:top;
    border:1px solid red;
}

.seven {max-width:770px;} /* this is the number of block * their outer width (margin + border + padding + width) */

/*one block*/
@media (max-width:219px) { /* this is the width of 2 blocks outer width -1px (you may need to add the width of the left and right column to this plus any left and right padding of the center column.  This is really the max width of the container div */
    .centered {
        width:110px; /* the outer width of a block */
    }
}

/*two blocks*/
/* keep adding media queries to either your max number of blocks or the largest screen size you want to support */
/*min width is 2 * 1 block outer width, max width is 3 * 1 block outer width - 1px*/
@media (min-width:220px) and (max-width:329px) {
    .centered {
        width:220px; /* the outer width of 2 blocks */
    }
}
@media (min-width:330px) and (max-width:439px) {
    .centered {
        width:330px;
    }
}
@media (min-width:440px) and (max-width:549px) {
    .centered {
        width:440px;
    }
}
@media (min-width:550px) and (max-width:659px) {
    .centered {
        width:550px;
    }
}
@media (min-width:660px) and (max-width:769px) {
    .centered {
        width:660px;
    }
}
@media (min-width:770px) and (max-width:879px) {
    .centered {
        width:770px;
    }
}
@media (min-width:880px) and (max-width:989px) {
    .centered {
        width:880px;
    }
}
@media (min-width:990px) and (max-width:1100px) {
    .centered {
        width:990px;
    }
}

＆＃13;

<div class="container">
    <div class="centered seven"><!--the seven class is the number of children blocks-->
        <div class="block"></div>
        <div class="block"></div>
        <div class="block"></div>
        <div class="block"></div>
        <div class="block"></div>
        <div class="block"></div>
        <div class="block"></div>
    </div>
</div>

＆＃13;

＆＃13;

＆＃13;

Fiddle Example

Otherwise you can try a js solution

Answer 2

您可以在内联块的末尾添加不可见的占位符。这将左对齐最后一行。

http://jsfiddle.net/aakt65x4/

但是，如果你没有填满第一行，那么整个事物将显示为左对齐。但我认为这就是你想要的，对吧？

<强> HTML：

<!--
  Centers a group of boxes that wrap to the width of its container.
  Also left-aligns them inside the container.
  Issue: Does not center group if there aren't enough boxes to fill
  the first row.
  -->
<div class="container">
    <div class="block"></div>
    <div class="block"></div>
    <div class="block"></div>
    <div class="block"></div>
    <div class="block"></div>
    <div class="block"></div>
    <div class="block"></div>
    <div class="block"></div>
    <div class="block"></div>
    <div class="block"></div>

    <!--
      How many placeholders do you need?
      At least the number of blocks minus two.
      -->
    <div class="placeholder"></div>
    <div class="placeholder"></div>
    <div class="placeholder"></div>
    <div class="placeholder"></div>
    <div class="placeholder"></div>
    <div class="placeholder"></div>
    <div class="placeholder"></div>
    <div class="placeholder"></div>
</div>

<强> CSS：

body {
    text-align: center;     /* center a max-width container */
    font-size: 0;           /* remove spaces between blocks */
}
.container {                /* you don't need this */
    background-color: #eee; /* so you can see what's happening */
    max-width: 960px;       /* to demonstrate the centering of a max-width container */
    display: inline-block;  /* center the max-width container */
    text-align: center;     /* center the group of blocks */
}
.block {
    display: inline-block;  /* left-align within the group */
    background-color: red;  /* so you can see what's happening */
    height: 100px;
    width: 100px;
    margin: 10px;
}
.placeholder {
    display: inline-block;  /* add to the line of blocks */
    width: 120px;           /* width + margin of a block */
}