// 解决定时器切后台时间停止问题(that.orderData.valid_order_period 此为页面显示定时器)
addVisibilitychange() {
let that = this;
let start, end, s;
document.addEventListener('visibilitychange', function() {
if(document.visibilityState == 'hidden') {
start = new Date().getTime(); //开始切后台时间戳
}else if(document.visibilityState == 'visible') {
end = new Date().getTime(); //切后台之后返回显示的时间戳
s = Math.floor((end - start)/1000);
that.orderData.valid_order_period = that.orderData.valid_order_period - s;
if(that.orderData.valid_order_period <= 0) {
that.orderData.valid_order_period = 0;
window.clearInterval(that.timer);
}
}else { }
})
