我的解决方案是:

.parent {
    display: flex;
    flex-wrap: wrap;
}

.product {
    width: 240px;
    margin-left: auto;
    height: 127px;
    margin-right: auto;
}

2015年2月27日更新:我最初的答案不断被投票，但现在我通常使用@bobince的方法。

.child { /* This is the item to center... */
  display: inline-block;
}
.parent { /* ...and this is its parent container. */
  text-align: center;
}

出于历史目的，我原来的帖子是:

您可能想尝试这种方法。

<div class="product_container">
    <div class="outer-center">
        <div class="product inner-center">
        </div>
    </div>
    <div class="clear"/>
</div>

下面是匹配的样式:

.outer-center {
    float: right;
    right: 50%;
    position: relative;
}
.inner-center {
    float: right;
    right: -50%;
    position: relative;
}
.clear {
    clear: both;
}

JSFiddle

The idea here is that you contain the content you want to center in two divs, an outer one and an inner one. You float both divs so that their widths automatically shrink to fit your content. Next, you relatively position the outer div with it's right edge in the center of the container. Lastly, you relatively position the inner div the opposite direction by half of its own width (actually the outer div's width, but they are the same). Ultimately that centers the content in whatever container it's in.

如果你依赖于你的“product”内容来调整“product_container”的高度，你可能需要在结尾使用空的div。

恐怕唯一不显式指定宽度的方法是使用(gasp)表。

我的解决方案是:

.parent {
    display: flex;
    flex-wrap: wrap;
}

.product {
    width: 240px;
    margin-left: auto;
    height: 127px;
    margin-right: auto;
}

<div class="product_container">
<div class="outer-center">
<div class="product inner-center">
    </div>
</div>
<div class="clear"></div>
</div>

.outer-center
{
float: right;
right: 50%;
position: relative;
}
.inner-center 
{
float: right;
right: -50%;
position: relative;
}
.clear 
{
clear: both;
}

.product_container
{
overflow:hidden;
}

如果你不提供"overflow:hidden"为"。Product_container”，“outer-center”div将与它右边的其他附近内容重叠。任何链接或按钮的右边“外中心”不会工作。尝试“outer-center”的背景色来理解“overflow:hidden”的需求

试试这个新的css和标记

下面是修改后的HTML:

<div class="product_container">
<div class="products" id="products">
   <div id="product_15" class="products_box">
       <img src="/images/ecommerce/card_default.png">
       <div class="price">R$ 0,01</div>
   </div>
   <div id="product_15" class="products_box">
       <img src="/images/ecommerce/card_default.png">
       <div class="price">R$ 0,01</div>
   </div>   
   <div id="product_15" class="products_box">
       <img src="/images/ecommerce/card_default.png">
       <div class="price">R$ 0,01</div>
   </div>
</div>

这里是修改后的CSS:

<pre>
.product_container 
 {
 text-align:    center;
 height:        150px;
 }

.products {
    left: 50%;
height:35px;
float:left;
position: relative;
margin: 0 auto;
width:auto;
}
.products .products_box
{
width:auto;
height:auto;
float:left;
  right: 50%;
  position: relative;
}
.price {
    margin:        6px 2px;
    width:         137px;
    color:         #666;
    font-size:     14pt;
    font-style:    normal;
    border:        1px solid #CCC;
    background-color:   #EFEFEF;
}