设置子节点相对于父节点水平竖直都居中

//父节点设置flex布局
display: flex;
align-items: center;
justify-content: center;

 

dom.style.display = 'flex'
dom.style.alignItems =  'center'
dom.style.justifyContent = 'center'

let img = document.createElement('img')
img.src = trash
img.style.width = '50%'
// img.style.height = 15
dom.appendChild(img)
// removeChild(dom)