代码在这里：

页面一、 勾选商品选项

为防止刷新页面引起的时间戳和随机数的变动，所以这俩var需要在前一个页面设置好
var rand_str = Math.random();
rand_str = rand_str*2000;
rand_str = Math.ceil(rand_str);
var time = Date.parse(new Date());
time = time /1000 ;

带上选好的参数调到支付页面，上边有调用微信公众号支付的按钮
location.href = 'makeorder/coinrecharge2?data_re='+data_re+'&data_co='+data_co+'&id='+id+'&rand_str='+rand_str+'&time='+time+'';

页面二、 接收上个页面传来的参数，用laravel的对象，不用数组，数组遇到空白会报错。
设置订单生成时间：$createtime = time();

$row = [
'user_id' => $id ,
'out_trade_no' => $out_trade_no ,
'data_re' => $data_re ,
'data_co' => $data_co ,
'pay_status' => 0,
'createtime' => $createtime
];

    session_start();
    if($row['user_id']){
        $json = json_encode($row);
        $_SESSION['json'] = $json;
        $_SESSION['out_trade_no'] = $row['out_trade_no'];
    }

如果是form表单提交：

        <input type="hidden" name="rand_str" id="rand_str">
        <input type="hidden" name="time" id="time">
        <script src='https://code.jquery.com/jquery-3.2.1.min.js'></script>
        <script type="text/javascript">
            var rand_str = Math.random();
            rand_str = rand_str*2000;
            rand_str = Math.ceil(rand_str);

            var time = Date.parse(new Date());
            time = time /1000 ;

            $("#rand_str").val(rand_str);
            $("#time").val(time);

        </script>