统一下单需要先拿到微信用户openid

相关资源:小程序获取openid php

小程序端

 wx.request({
     url: '统一下单地址',
     data: {
         openid: openid.data.openid,
         payAmount: '金额',
         orderName: '商品名称',
     },
     success: function(results) {
         let tempArr = (results.data);
         wx.requestPayment({
             timeStamp: '' + tempArr.timeStamp,
             nonceStr: tempArr.nonceStr,
             package: tempArr.package,
             signType: tempArr.signType,
             paySign: tempArr.paySign,
             success(res) {
                 //   支付成功
             },
         })
     },
 });

PHP

<?php


header('Content-type: text/plain; charset=utf-8');

$mchid = '';          //微信支付商户号 PartnerID 通过微信支付商户资料审核后邮件发送
$appid = '';  //微信支付申请对应的公众号的APPID 
$apiKey = '';   //https://pay.weixin.qq.com 帐户设置-安全设置-API安全-API密钥-设置API密钥 

//①、获取用户openid
$wxPay = new WxpayService($mchid, $appid, $appKey, $apiKey);
$openId = $_REQUEST['openid'];     //获取openid
if (!$openId) exit('获取openid失败');
//②、统一下单
$outTradeNo = uniqid();     //你自己的商品订单号
$payAmount = $_REQUEST['payAmount'];          //付款金额，单位:元
$orderName = $_REQUEST['orderName'];    //订单标题
$notifyUrl = 'https://baidu.com/notify.php';     //付款成功后的回调地址(不要有问号)
$payTime = time();      //付款时间
$jsApiParameters = $wxPay->createJsBizPackage($openId, $payAmount, $outTradeNo, $orderName, $notifyUrl, $payTime);

echo (json_encode($jsApiParameters));

class WxpayService
{
    protected $mchid;
    protected $appid;
    protected $appKey;
    protected $apiKey;
    public $data = null;
    public function __construct($mchid, $appid, $appKey, $key)
    {
        $this->mchid = $mchid; //https://pay.weixin.qq.com 产品中心-开发配置-商户号
        $this->appid = $appid; //微信支付申请对应的公众号的APPID
        $this->appKey = $appKey; //微信支付申请对应的公众号的APP Key
        $this->apiKey = $key;   //https://pay.weixin.qq.com 帐户设置-安全设置-API安全-API密钥-设置API密钥
    }

    /**
     * 构造获取code的url连接
     * @param string $redirectUrl 微信服务器回跳的url，需要url编码
     * @return 返回构造好的url
     */
    private function __CreateOauthUrlForCode($redirectUrl)
    {
        $urlObj["appid"] = $this->appid;
        $urlObj["redirect_uri"] = "$redirectUrl";
        $urlObj["response_type"] = "code";
        $urlObj["scope"] = "snsapi_base";
        $urlObj["state"] = "STATE" . "#wechat_redirect";
        $bizString = $this->ToUrlParams($urlObj);
        return "https://open.weixin.qq.com/connect/oauth2/authorize?" . $bizString;
    }
    /**
     * 拼接签名字符串
     * @param array $urlObj
     * @return 返回已经拼接好的字符串
     */
    private function ToUrlParams($urlObj)
    {
        $buff = "";
        foreach ($urlObj as $k => $v) {
            if ($k != "sign") $buff .= $k . "=" . $v . "&";
        }
        $buff = trim($buff, "&");
        return $buff;
    }
    /**
     * 统一下单
     * @param string $openid 调用【网页授权获取用户信息】接口获取到用户在该公众号下的Openid
     * @param float $totalFee 收款总费用 单位元
     * @param string $outTradeNo 唯一的订单号
     * @param string $orderName 订单名称
     * @param string $notifyUrl 支付结果通知url 不要有问号
     * @param string $timestamp 支付时间
     * @return string
     */
    public function createJsBizPackage($openid, $totalFee, $outTradeNo, $orderName, $notifyUrl, $timestamp)
    {
        $config = array(
            'mch_id' => $this->mchid,
            'appid' => $this->appid,
            'key' => $this->apiKey,
        );
        $nonce_str = self::createNonceStr();
        //$orderName = iconv('GBK','UTF-8',$orderName);
        $unified = array(
            'appid' => $config['appid'],
            'attach' => 'pay',             //商家数据包，原样返回，如果填写中文，请注意转换为utf-8
            'body' => $orderName,
            'mch_id' => $config['mch_id'],
            'nonce_str' => $nonce_str,
            'notify_url' => $notifyUrl,
            'openid' => $openid,            //rade_type=JSAPI，此参数必传
            'out_trade_no' => $outTradeNo,
            'spbill_create_ip' => '127.0.0.1',
            'total_fee' => intval($totalFee * 100),       //单位 转为分
            'trade_type' => 'JSAPI',
        );
        $unified['sign'] = self::getSign($unified, $config['key']);
        $responseXml = self::curlPost('https://api.mch.weixin.qq.com/pay/unifiedorder', self::arrayToXml($unified));
        //禁止引用外部xml实体
        libxml_disable_entity_loader(true);
        $unifiedOrder = simplexml_load_string($responseXml, 'SimpleXMLElement', LIBXML_NOCDATA);
        if ($unifiedOrder === false) {
            die('parse xml error');
        }
        if ($unifiedOrder->return_code != 'SUCCESS') {
            die($unifiedOrder->return_msg);
        }
        if ($unifiedOrder->result_code != 'SUCCESS') {
            die($unifiedOrder->err_code);
        }

        $arr = array(
            "appId" => $config['appid'],
            "timeStamp" => "$timestamp",
            "nonceStr" =>  $nonce_str,
            "package" => "prepay_id=" . $unifiedOrder->prepay_id,
            "signType" => 'MD5',
        );
        $arr['paySign'] = self::getSign($arr, $config['key']);
        return $arr;
    }
    public static function curlGet($url = '', $options = array())
    {
        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_TIMEOUT, 30);
        if (!empty($options)) {
            curl_setopt_array($ch, $options);
        }
        //https请求 不验证证书和host
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
        $data = curl_exec($ch);
        curl_close($ch);
        return $data;
    }
    public static function curlPost($url = '', $postData = '', $options = array())
    {
        if (is_array($postData)) {
            $postData = http_build_query($postData);
        }
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $postData);
        curl_setopt($ch, CURLOPT_TIMEOUT, 30); //设置cURL允许执行的最长秒数
        if (!empty($options)) {
            curl_setopt_array($ch, $options);
        }
        //https请求 不验证证书和host
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
        $data = curl_exec($ch);
        curl_close($ch);
        return $data;
    }
    public static function createNonceStr($length = 16)
    {
        $chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
        $str = '';
        for ($i = 0; $i < $length; $i++) {
            $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
        }
        return $str;
    }
    public static function arrayToXml($arr)
    {
        $xml = "<xml>";
        foreach ($arr as $key => $val) {
            if (is_numeric($val)) {
                $xml .= "<" . $key . ">" . $val . "</" . $key . ">";
            } else
                $xml .= "<" . $key . "><![CDATA[" . $val . "]]></" . $key . ">";
        }
        $xml .= "</xml>";
        return $xml;
    }
    public static function getSign($params, $key)
    {
        ksort($params, SORT_STRING);
        $unSignParaString = self::formatQueryParaMap($params, false);

        $signStr = strtoupper(md5($unSignParaString . "&key=" . $key));
        return $signStr;
    }
    protected static function formatQueryParaMap($paraMap, $urlEncode = false)
    {
        $buff = "";
        ksort($paraMap);
        foreach ($paraMap as $k => $v) {
            if (null != $v && "null" != $v) {
                if ($urlEncode) {
                    $v = urlencode($v);
                }
                $buff .= $k . "=" . $v . "&";
            }
        }
        $reqPar = '';
        if (strlen($buff) > 0) {
            $reqPar = substr($buff, 0, strlen($buff) - 1);
        }
        return $reqPar;
    }
}