如何在CSS中居中透明背景的图像？

Question

I had some content with search button. if i click the search button it needs to appear a processing gif image which should be in center with transparent background. The content something looks like this. Thanks in advance for every answers

 .img-loader{ text-align: center; width: 50px; display: block; margin: 0 auto; } .wrapper{ margin: 0 auto; width: 100%; height: 100%; background: rgba(0, 135, 0, 0.1); position: absolute; top: 0; } 

 <div class="content"> <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p> <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p> <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p> </div> <div class="wrapper"> <img src="http://michaelrienstra.com/jquery.cspinner/demo/spinner.gif" class="img-loader"> </div> 

Answer 1

Change your css for img like this

.img-loader{
    text-align: center;
    width: 50px;
    display: block;
    position:absolute;
    left:0;
    right:0;
    top:0;
    bottom:0;
    margin:auto;
}

 .img-loader{ text-align: center; width: 50px; display: block; position:absolute; left:0; right:0; top:0; bottom:0; margin:auto; } .wrapper{ margin: 0 auto; width: 100%; height: 100%; background: rgba(0, 135, 0, 0.1); position: absolute; top: 0; } 

 <div class="content"> <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p> <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p> <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p> </div> <div class="wrapper"> <img src="https://pixabay.com/static/uploads/photo/2015/08/31/15/29/person-915604_640.jpg" class="img-loader"> </div> 

Answer 2

Try like this: Demo

.img-loader {      
    position: absolute;
    top: 50%;
    left: 50%;
    margin: -28px 0 0 -25px;
}
.wrapper {
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    right: 0;
}

HTML:

<div class="wrapper">
    <img src="http://michaelrienstra.com/jquery.cspinner/demo/spinner.gif" alt="" class="img-loader" />
</div>

Answer 3

Rather than using top and position properties, you can try doing it this way:

.img-loader{ 
    width:50px;
    display: inline-block;
    margin:0 auto; 
}

This will keep the image center-align .