.myDiv{
position: absolute;
top: 50%;
left: 50%;
transform: translateX(-50%) translateY(-50%)
}
在父窗体上声明
<div style={{height:'100px',width:"100px",backgroundColor:"ActiveBorder",position:"relative",display:"flex",alignItems:"center",justifyContent:"center"}}>
标签：居中,translateX,translateY,50%,垂直,css From： https://www.cnblogs.com/sexintercourse/p/16826875.html