div 中的中心图像

center image in a div

我正在尝试将 div 中的图像水平居中,但我不明白为什么它不起作用...我已经多次将图像居中,这次我只是不明白... 这是我试过的...

CSS

#cabeca{
position: relative;
float: left;
width: 100%;
height: auto;
min-height: 290px;
margin: auto;
}

.cabecasize {
width:100%;
min-width: 968px;
height:auto;
min-height: 290px;
overflow:hidden;
left:0;
right: 0;
margin: auto;
}

.cabecafundo{
position: absolute;
width: 100vw;
left: calc(-50vw + 50%);
background-color: black;
height: 100%;
top:0;
z-index: -1;
}

.overcabeca{
overflow: hidden;
display: block;
margin: auto;
text-align: center;
}

HTML

<div id="cabeca">
    <div class="overcabeca">
        <img src="images/av61.png" alt="av61" class="cabecasize" />
    </div>
    <div class="cabecafundo">
    </div>
</div>  

有什么想法吗??

检查以下代码,希望对您有所帮助。

.wrap{
  position: relative;
  height: 100vh;
  width: 100vw;
}
.midImg{
  margin: auto;  
  position: absolute;
  left:0;
  right: 0;
  top: 0;
  bottom: 0;
  height: 150px;
  width: 150px;
}  
<div class="wrap">
  <img src="https://pbs.twimg.com/profile_images/473506797462896640/_M0JJ0v8.png" alt="av61" class="midImg" />
</div>

您只需将此 css 添加到您的图片中即可

img{
   margin-left: auto;
   margin-right: auto;
}

.image {
  text-align: center;
  background: #c0c0c0;
  border: #a0a0a0 solid 1px;

}

.image:before {
  content: '0B';
/*   content: '';
  margin-left: -0.25em; */
  display: inline-block;
  height: 100%; 
  vertical-align: middle;
 }

.centered {
  display: inline-block;
  vertical-align: middle;
  width: 300px;
  padding: 10px 15px;
   }

<div class="image" style="height: 600px;">
    <div class="centered">
        <img src="download.jpg"  alt="" />
    </div>
</div>