1、下载微信支付SDK  

2、直接引用

<?php
   
header("Content-type:text/html; charset=utf-8;");
error_reporting(0);
//获取数据库配置
 
$con = mysql_connect("127.0.0.1","xxxxx","xxxxxx");   //连接数据库
mysql_select_db("xxxxx", $con);                       //选择数据库
$query = mysql_query("SELECT * FROM config");
$result = mysql_fetch_array($query);
define("APPID", $result['wx_appid']);
define("MCHID", $result['wx_mchid']);
define("KEY", $result['wx_key']);

require_once "lib/WxPay.Api.php";
require_once "WxPay.NativePay.php";


$orderid = $_GET['orderid'];
$notify = new NativePay();

$input = new WxPayUnifiedOrder();
$input->SetBody("会员充值");
$input->SetAttach("member");
$input->SetOut_trade_no($orderid);
$input->SetTotal_fee($_GET['money']*100);
$input->SetTime_start(date("YmdHis"));
$input->SetTime_expire(date("YmdHis", time() + 600));
$input->SetNotify_url("http://".$_SERVER['HTTP_HOST']."/api/pay/wxnotify");
$input->SetTrade_type("NATIVE");
$input->SetProduct_id("123456789");
$result = $notify->GetPayUrl($input);
//$url2 = $result["code_url"];
echo json_encode($result);
?>