使用ThinkPHP5写的微信支付,$res数组下是要使用到的数据

    //微信支付
    public function Pay()
    {
        $res = request()->param();

        //注意::::117行需要填写商户密钥wx_key
        //总金额
        $res['total_fee'] = intval($res['total_fee'] * 100);
        //appid
        $appid = $res['appid'];
        $body = '内容体';
        $mch_id = '商户号';
        //随机字符串
        $nonce_str = $this->nonce_str();
        $notify_url = '回调地址,一个url';
        //用户openid
        $openid = $res['openid'];
        //商户订单号
        $out_trade_no = $res['orderid'];
        $spbill_create_ip = '终端ip 随意 无强制要求';
        //总价
        $total_fee = $res['total_fee'];
        $trade_type = 'JSAPI';

        $post['appid'] = $appid;
        $post['body'] = $body;
        $post['mch_id'] = $mch_id;
        $post['nonce_str'] = $nonce_str;
        $post['notify_url'] = $notify_url;
        $post['openid'] = $openid;
        $post['out_trade_no'] = $out_trade_no;
        $post['spbill_create_ip'] = $spbill_create_ip;
        $post['total_fee'] = $total_fee;
        $post['trade_type'] = $trade_type;
        $sign = $this->sign($post);


        $post_xml = '<xml>
           <appid>' . $appid . '</appid>
           <body>' . $body . '</body>
           <mch_id>' . $mch_id . '</mch_id>
           <nonce_str>' . $nonce_str . '</nonce_str>
           <notify_url>' . $notify_url . '</notify_url>
           <openid>' . $openid . '</openid>
           <out_trade_no>' . $out_trade_no . '</out_trade_no>
           <spbill_create_ip>' . $spbill_create_ip . '</spbill_create_ip>
           <total_fee>' . $total_fee . '</total_fee>
           <trade_type>' . $trade_type . '</trade_type>
           <sign>' . $sign . '</sign>
        </xml> ';

        //统一接口prepay_id
        $url = 'https://api.mch.weixin.qq.com/pay/unifiedorder';
        $xml = $this->http_request($url, $post_xml);
        $array = $this->xml($xml);//全要大写

        if ($array['RETURN_CODE'] == 'SUCCESS' && $array['RESULT_CODE'] == 'SUCCESS') {
            $time = time();
            $tmp = [];//临时数组用于签名
            $tmp['appId'] = $appid;
            $tmp['nonceStr'] = $nonce_str;
            $tmp['package'] = 'prepay_id=' . $array['PREPAY_ID'];
            $tmp['signType'] = 'MD5';
            $tmp['timeStamp'] = "$time";

            $data['state'] = 1;
            $data['timeStamp'] = "$time";//时间戳
            $data['nonceStr'] = $nonce_str;//随机字符串
            $data['signType'] = 'MD5';//签名算法,暂支持 MD5
            $data['package'] = 'prepay_id=' . $array['PREPAY_ID'];
            //统一下单接口返回的 prepay_id 参数值,提交格式如:prepay_id=*
            $data['paySign'] = $this->sign($tmp);//签名,具体签名方案参见微信公众号支付帮助文档;
            $data['out_trade_no'] = $out_trade_no;
        } else {
            $data['state'] = 0;
            $data['text'] = "错误";
            $data['RETURN_CODE'] = $array['RETURN_CODE'];
            $data['RETURN_MSG'] = $array['RETURN_MSG'];
        }
        return json($data);
    }


    //随机32位字符串
    public function nonce_str()
    {
        $result = '';
        $str = 'QWERTYUIOPASDFGHJKLZXVBNMqwertyuioplkjhgfdsamnbvcxz';
        for ($i = 0; $i < 32; $i++) {
            $result .= $str[rand(0, 48)];
        }
        return $result;
    }


    //生成订单号
    private function order_number($openid)
    {
        //date('Ymd',time()).time().rand(10,99);//18位
        return md5($openid . time() . rand(10, 99));//32位
    }


    //签名 $data要先排好顺序
    private function sign($data)
    {
        $stringA = '';
        foreach ($data as $key => $value) {
            if (!$value) continue;
            if ($stringA) $stringA .= '&' . $key . "=" . $value;
            else $stringA = $key . "=" . $value;
        }
        $wx_key = '商户密钥wx_key';
        $stringSignTemp = $stringA . '&key=' . $wx_key;
        return strtoupper(md5($stringSignTemp));
    }


    //curl请求啊
    function http_request($url, $data = null, $headers = array())
    {

        $curl = curl_init();
        if (count($headers) >= 1) {
            curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);
        }

        curl_setopt($curl, CURLOPT_URL, $url);

        curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE);
        curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, FALSE);

        if (!empty($data)) {
            curl_setopt($curl, CURLOPT_POST, 1);
            curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
        }
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
        $output = curl_exec($curl);
        curl_close($curl);
        return $output;
    }


    //获取xml
    private function xml($xml)
    {
        $p = xml_parser_create();
        xml_parse_into_struct($p, $xml, $vals, $index);
        xml_parser_free($p);
        $data = [];
        foreach ($index as $key => $value) {
            if ($key == 'xml' || $key == 'XML') continue;
            $tag = $vals[$value[0]]['tag'];
            $value = $vals[$value[0]]['value'];
            $data[$tag] = $value;
        }
        return $data;
    }