var bag2=document.getElementsByClassName("bag2")[0];
bag2.classList.remove('style2');
bag2.classList.remove('style3');
bag2.classList.add('style1');
转载于:https://www.cnblogs.com/yaomengli/p/6937696.html
var bag2=document.getElementsByClassName("bag2")[0];
bag2.classList.remove('style2');
bag2.classList.remove('style3');
bag2.classList.add('style1');
转载于:https://www.cnblogs.com/yaomengli/p/6937696.html