==transform 居中==

   .wrap{           //父
    position: relative;
    border: 1px solid red;
    width: 300px;
    height: 300px;
  }

  .child {			//子
    position: absolute;
    width: 100px;
    height: 100px;
    background-color: green;
    top: 50%;
    left: 50%;
    transform: translate(-50%,-50%);
  }

absolute +margin auto

		
		
.child {
    position: absolute;;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;

absolute + calc

这种方式也要求居中元素的宽高必须固定

.wp {
    position: relative;
}
.box {
    position: absolute;;
    top: calc(50% - 50px);  // 50% 为top百分值             50px为 子级 一半 宽都    
    left: calc(50% - 50px);

absolte + 负margin

 
/* 定位代码 */
.father {
    position: relative;
}
.son {
    position: absolute;;
    top: 50%;
    left: 50%;
    margin-left: -50px;
    margin-top: -50px;
}
 
 

lineheigth

.father {
    line-height: 300px;
    text-align: center;
    font-size: 0px;
}
.son {
    font-size: 16px;
    display: inline-block;
    vertical-align: middle;
    line-height: initial;
    text-align: left; /* 修正文字 */
}

flex

.father {
    display: flex;
    justify-content: center;
    align-items: center;
}

grid

.father {
    display: grid;
}
.son {
    align-self: center;
    justify-self: center;
}

==总结==

转自www.jianshu.com/p/907f99004…