html中alert弹窗自动消失 模拟alert2秒后自动消失弹出框

//显示框信息

function showMsg(val,time){

if(!document.getElementById('parent_pop_up')){

var parent_pop_up = document.createElement('div');

parent_pop_up.id = "parent_pop_up";

parent_pop_up.style.cssText = "position: fixed; z-index: 9999; bottom: 5rem; width: 100%;";

var poo_up = document.createElement('div');

poo_up.id = 'poo_up';

poo_up.style.cssText = 'height: 1rem; margin:0 auto; text-align: center;';

var span = document.createElement('span');

span.style.cssText = 'background-color: rgba(0,0,0,0.6); padding: 0.2rem 0.35rem; letter-spacing: 1px; border-radius: 5px; color: #FFFFFF; font-size: 0.34rem; text-align: center;';

span.innerHTML = val;

poo_up.appendChild(span);

parent_pop_up.appendChild(poo_up);

document.body.appendChild(parent_pop_up);

if(time == null || time == ''){

time = 2000;

}

setTimeout(function(){hideMsg();},time);

}

}

//隐藏显示框

function hideMsg(){

var pop = document.getElementById('parent_pop_up');

pop.style.display = 'none';

document.body.removeChild(pop);

}