button按钮居中:
<button class="btn"></button>
css文件:.btn{margin:0 auto;display:block;
<ion-content class="transparent-header"></ion-content>
css中:.transparent-header{
background-image: url(../../assets/img/background/3.jpg);
background-size: cover;
background-position: center;
background-repeat: no-repeat;
指定背景图片和样式,居中,平铺