//配置調起支付前的配置引數
    public $config=array(
        'appid'=>'',// 開放平臺appid
        'mch_id'=>'',//商戶id
        'device_info'=>'web',
        'api_key'=>'',//商戶密匙
        'nonce_str'=>'設定的隨機字串',//隨機字串
        'sign_type'=>'MD5',
        'body'=>'app支付訂單',
        'out_trade_no'=>'',//訂單號
        'total_fee'=>'',//總金額
        'spbill_create_ip'=>'',//使用者端ip
        'notify_url'=>'',//回撥地址
        'trade_type'=>'APP'
    );


    public function pay(){
       //填寫基本資訊
        //獲取當前伺服器ip
        function get_client_ip()
        {
            if ($_SERVER['REMOTE_ADDR']) {
                $cip = $_SERVER['REMOTE_ADDR'];
            } elseif (getenv("REMOTE_ADDR")) {
                $cip = getenv("REMOTE_ADDR");
            } elseif (getenv("HTTP_CLIENT_IP")) {
                $cip = getenv("HTTP_CLIENT_IP");
            } else {
                $cip = "unknown";
            }
            return $cip;
        }
        $host = isset($_SERVER['HTTP_X_FORWARDED_HOST']) ? $_SERVER['HTTP_X_FORWARDED_HOST'] : (isset($_SERVER['HTTP_HOST']) ? $_SERVER['HTTP_HOST']:'');

        $out_trade_no=$_POST['osn'];//訂單號
        $total_fee = $_POST['total_fee'];//價格
        //除錯
        // $out_trade_no=$_GET['osn'];//訂單號
        // $total_fee = $_GET['total_fee'];//價格

        //獲取指定長度的隨機字串
        function getRandChar($length){
            $str = null;
            $strPol = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz";
            $max = strlen($strPol)-1;
            for($i=0;$i<$length;$i++){
                $str.=$strPol[rand(0,$max)];//rand($min,$max)生成介於min和max兩個數之間的一個隨機整數
            }
            return $str;
        }
        // echo getRandChar(32);exit;
        $data['appid']=$this->config['appid'];
        $data['mch_id']=$this->config['mch_id'];
        $data['device_info']=$this->config['device_info'];
        $data['nonce_str']=getRandChar(32); //隨機字串
        // $data['nonce_str']=$this->config['nonce_str']; //隨機字串測試
        $data['body']=$this->config['body'];
        $data['out_trade_no']=$out_trade_no;
        $data['total_fee']=$total_fee*100;
        $data['spbill_create_ip ']=$_SERVER['REMOTE_ADDR'];//使用者ip  
        $data['trade_type']='APP';
        $data['notify_url']=$this->config['notify_url'];

        if($out_trade_no=='' or $total_fee==''){
            $sever=array();
            $sever['code']='4001';
            $sever['message']='無引數或引數錯誤';
            $sever['info']='';
            echo json_encode($sever); 
            exit;
        }

        //生成第一次簽名陣列字典排序
        ksort($data);
        // echo $data;

        //字串拼接 
        foreach ($data as $key => $value) {
            $stringA.=$key.'='.$value.'&';
        }
       

        //第二次拼接得到簽名
        $stringSignTemp=$stringA."key=".$this->config['api_key'];
         // echo $stringSignTemp;
        $stringSignTemp=preg_replace('# #','',$stringSignTemp);
        // echo $stringSignTemp;
        $data['sign']=strtoupper(MD5($stringSignTemp));//
        // echo $data['sign'];
        // var_dump($data);exit;

        //陣列轉xml
        $xml='<xml>';
        foreach ($data as $key => $value) {
            
            $xml=$xml.'<'.$key.'><![CDATA['.$value.']]></'.$key.'>';
        }

        $xml=$xml.'</xml>';
        // echo $xml;
        // exit;
        // echo json_encode($data);
        
        //準備要傳送的請求
        $payurl = "https://api.mch.weixin.qq.com/pay/unifiedorder";  //微信統一下單介面地址

        //傳送xml的方法
        function postXmlCurl($xml, $url, $useCert = false, $second = 30){       
            $ch = curl_init();
            //設定超時
            curl_setopt($ch, CURLOPT_TIMEOUT, $second);
            curl_setopt($ch,CURLOPT_URL, $url);
            curl_setopt($ch,CURLOPT_SSL_VERIFYPEER,FALSE);
            curl_setopt($ch,CURLOPT_SSL_VERIFYHOST,2);
            //設定header
            curl_setopt($ch, CURLOPT_HEADER, FALSE);
            //要求結果為字串且輸出到螢幕上
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
            if($useCert == true){
                //設定證書
                //使用證書：cert 與 key 分別屬於兩個.pem檔案
                curl_setopt($ch,CURLOPT_SSLCERTTYPE,'PEM');
                //curl_setopt($ch,CURLOPT_SSLCERT, WxPayConfig::SSLCERT_PATH);
                curl_setopt($ch,CURLOPT_SSLKEYTYPE,'PEM');
                //curl_setopt($ch,CURLOPT_SSLKEY, WxPayConfig::SSLKEY_PATH);
            }
            //post提交方式
            curl_setopt($ch, CURLOPT_POST, TRUE);
            curl_setopt($ch, CURLOPT_POSTFIELDS, $xml);
            //執行curl
            $data = curl_exec($ch);
            //返回結果
            if($data){
                curl_close($ch);
                return $data;
            } else { 
                $error = curl_errno($ch);
                curl_close($ch);
                return false;
            }
        }
        $Wxinxml= postXmlCurl($xml,$payurl);
        
        $parser = xml_parser_create(); //建立解析器   
        xml_parse_into_struct($parser, $Wxinxml, $values, $index);
         //解析到陣列   
         xml_parser_free($parser); //釋放資源   //顯示陣列結構   
    
         // print_r($values); 
         // var_dump($values);exit;
         $Arlist=array();
         for($i=0;$i<count($values);$i++){
            if($values[$i]['tag']!='XML'){
                $Arlist[$values[$i]['tag']]=$values[$i]['value'];
            }
         }
         if($Arlist['RETURN_CODE']!='SUCCESS'){
            $sever=array();
            $sever['code']='4005';
            $sever['message']='訂單生成失敗';
            $sever['info']='';
            echo json_encode($sever); 
            exit;

         }

         // var_dump($Arlist);exit;
         //時間戳
        $time=time();
        

        $warr=array(
            'appid'=>$Arlist['APPID'],
            'partnerid'=>$Arlist['MCH_ID'],
            // 'device_info'=>$Arlist['DEVICE_INFO'],
            'noncestr'=>$Arlist['NONCE_STR'],
            'prepayid'=>$Arlist['PREPAY_ID'],
            'package'=>"Sign=WXPay",
            // 'trade_type'=>$Arlist['TRADE_TYPE'],
        );
        $warr['timestamp']=$time;
        

        //二次簽名
         ksort($warr); 
         $stringA='';
        foreach ($warr as $key => $value) {
            $stringA.=$key.'='.$value.'&';
        }
        $stringSignTemp=$stringA."key=".$this->config['api_key'];
        
        $stringSignTemp=preg_replace('# #','',$stringSignTemp);
        // echo $stringSignTemp;
        $warr['sign']=strtoupper(MD5($stringSignTemp));

        $sever=array();
        $sever['code']='200';
        $sever['message']='統一下單';
        $sever['info']=$warr;

        echo json_encode($sever); 
        exit;

    }