获取自适应的盒子高度

解决思路：延时一点时间再去获取内容的高度

    const oBox=document.getElementById("headbox");
    setTimeout(function(){
        console.log(oBox.scrollHeight)
    },100)

 实战代码：

<script>
    const oBox=document.getElementById("headbox");
    setTimeout(function(){
        console.log(oBox.scrollHeight);
        let marginTop = oBox.scrollHeight;
        $(".main-box").css('margin-top',marginTop);
    },100)
    
</script>