有一些技巧可以在div的中心显示内容或图像。一些答案非常好,我也完全同意。
CSS中的绝对水平和垂直居中
http://www.css-jquery-design.com/2013/12/css-techniques-absolute-horizontal-and-vertical-centering-in-css/
有十多种技术实例。现在由您决定。
毫无疑问,这display:table; display:table-Cell是一个更好的把戏。
以下是一些不错的技巧:
技巧1-使用 display:table; display:table-cell
的HTML
<div class="Center-Container is-Table">
  <div class="Table-Cell">
    <div class="Center-Block">
        CONTENT
    </div>
  </div>
</div>
CSS代码
.Center-Container.is-Table { display: table; }
.is-Table .Table-Cell {
  display: table-cell;
  vertical-align: middle;
}
.is-Table .Center-Block {
  width: 50%;
  margin: 0 auto;
}
技巧2-使用 display:inline-block
的HTML
<div class="Center-Container is-Inline">
  <div class="Center-Block">
     CONTENT
  </div>
</div>
CSS代码
.Center-Container.is-Inline {
  text-align: center;
  overflow: auto;
}
.Center-Container.is-Inline:after,
.is-Inline .Center-Block {
  display: inline-block;
  vertical-align: middle;
}
.Center-Container.is-Inline:after {
  content: '';
  height: 100%;
  margin-left: -0.25em; /* To offset spacing. May vary by font */
}
.is-Inline .Center-Block {
  max-width: 99%; /* Prevents issues with long content causes the content block to be pushed to the top */
  /* max-width: calc(100% - 0.25em) /* Only for Internet Explorer 9+ */
}
技巧3-使用 position:relative;position:absolute
<div style="position: relative; background: #ddd; border: 1px solid #ddd; height: 250px;">
  <div style="width: 50%; height: 60%; overflow: auto; margin: auto; position: absolute; top: 0; left: 0; bottom: 0; right: 0; background: #ccc; text-align: center;">
    <h4>ABSOLUTE CENTER, <br/>
WITHIN CONTAINER.</h4>
    <p>This box is absolutely centered, horizontally and vertically, within its container</p>
  </div>
</div>