/**将时间戳转为 2018-12-27 15:16:30 */
time(e) {
let date = new Date(e);
let Y = date.getFullYear() + '-';
let M = (date.getMonth()+1 < 10 ? '0'+(date.getMonth()+1) : date.getMonth()+1) + '-';
let D = (date.getDate() < 10 ? '0' + date.getDate() : date.getDate()) + ' ';
let h = (date.getHours() < 10 ? '0' + date.getHours() : date.getHours()) + ':';
let m = (date.getMinutes() < 10 ? '0' + date.getMinutes() : date.getMinutes()) + ':';
let s = (date.getSeconds() < 10 ? '0' + date.getSeconds() : date.getSeconds());
return Y+M+D+h+m+s
}