效果

代码

/**
 * 封装Toast提示
 * @param {提示信息} msg 
 * @param {延迟时间} duration 
 */
function Toast(msg, duration) {
  duration = isNaN(duration) ? 3000 : duration;
  var m = document.createElement('div');
  m.innerHTML = msg;
  m.style.cssText = "font-family:siyuan;max-width:60%;min-width: 150px;padding:0 14px;height: 40px;color: rgb(255, 255, 255);line-height: 40px;text-align: center;border-radius: 4px;position: fixed;top: 50%;left: 50%;transform: translate(-50%, -50%);z-index: 999999;background: rgba(0, 0, 0,.7);font-size: 16px;";
  document.body.appendChild(m);
  setTimeout(function () {
    var d = 0.5;
    m.style.webkitTransition = '-webkit-transform ' + d + 's ease-in, opacity ' + d + 's ease-in';
    m.style.opacity = '0';
    setTimeout(function () {
      document.body.removeChild(m)
    }, d * 1000);
  }, duration);
}