PHP development of WeChat refund function case

function Home_index() {

  date_default_timezone_set("Asia/Shanghai");

  $date = date("YmdHis");

  $appid = "";

  $mch_id = "";

  $out_trade_no = "14487658021497944120";

  $op_user_id = "";

  $out_refund_no = $date;

  $total_fee = "500";

  $refund_fee = "500";

//  $transaction_id = "4009542001201706206596667604";

  $key = "";

  $nonce_str = nonceStr();

  $ref = strtoupper(md5("appid=$appid&mch_id=$mch_id&nonce_str=$nonce_str&op_user_id=$op_user_id"

          . "&out_refund_no=$out_refund_no&out_trade_no=$out_trade_no&refund_fee=$refund_fee&total_fee=$total_fee"

          . "&key=$key")); //sign加密MD5

  $refund = array(

  'appid' =>$appid, //应用ID，固定

  'mch_id' => $mch_id, //商户号，固定

  'nonce_str' => $nonce_str, //随机字符串

  'op_user_id' => $op_user_id, //操作员

  'out_refund_no' => $out_refund_no, //商户内部唯一退款单号

  'out_trade_no' => $out_trade_no, //商户订单号,pay_sn码 1.1二选一,微信生成的订单号，在支付通知中有返回

  // 'transaction_id'=>'1',//微信订单号 1.2二选一,商户侧传给微信的订单号

  'refund_fee' => $refund_fee, //退款金额

  'total_fee' => $total_fee, //总金额

  'sign' => $ref//签名

  );

  $url = "https://api.mch.weixin.qq.com/secapi/pay/refund";

  ; //微信退款地址，post请求

  $xml = arrayToXml($refund);

  $ch = curl_init();

  curl_setopt($ch, CURLOPT_URL, $url);

  curl_setopt($ch, CURLOPT_HEADER, 1);

  curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

  curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1); //证书检查

  if ($useCert == true) {

    // 设置证书

    curl_setopt($ch, CURLOPT_SSLCERTTYPE, 'pem');

    curl_setopt($ch, CURLOPT_SSLCERT, dirname(__FILE__) . '/WxPay/cert/apiclient_cert.pem');

    curl_setopt($ch, CURLOPT_SSLCERTTYPE, 'pem');

    curl_setopt($ch, CURLOPT_SSLKEY, dirname(__FILE__) . '/WxPay/cert/apiclient_key.pem');

    curl_setopt($ch, CURLOPT_SSLCERTTYPE, 'pem');

    curl_setopt($ch, CURLOPT_CAINFO, dirname(__FILE__) . '/WxPay/cert/rootca.pem');

  }

  curl_setopt($ch, CURLOPT_POST, 1);

  curl_setopt($ch, CURLOPT_POSTFIELDS, $xml);

  $xml = curl_exec($ch);

  // 返回结果0的时候能只能表明程序是正常返回不一定说明退款成功而已

  if ($xml) {

    curl_close($ch);

    // 把xml转化成数组

    libxml_disable_entity_loader(true);

    $xmlstring = simplexml_load_string($xml, 'SimpleXMLElement', LIBXML_NOCDATA);

//    var_dump($xmlstring);

    $result['errNum'] = 0;

    $result['info'] = object_to_array($xmlstring);

//    var_dump($result);

    return $result;

  } else {

    $error = curl_errno($ch);

    curl_close($ch);

    // 错误的时候返回错误码。

    $result['errNum'] = $error;

    return $result;

  }

}

function arrayToXml($arr) {

  $xml = "<root>";

  foreach ($arr as $key => $val) {

    if (is_array($val)) {

      $xml .= "<" . $key . ">" . arrayToXml($val) . "</" . $key . ">";

    } else {

      $xml .= "<" . $key . ">" . $val . "</" . $key . ">";

    }

  }

  $xml .= "</root>";

  return $xml;

}

function object_to_array($obj) {

  $obj = (array) $obj;

  foreach ($obj as $k => $v) {

    if (gettype($v) == 'resource') {

      return;

    }

    if (gettype($v) == 'object' || gettype($v) == 'array') {

      $obj[$k] = (array) object_to_array($v);

    }

  }

  return $obj;

}

function nonceStr() {

  $chars = "abcdefghijklmnopqrstuvwxyz0123456789";

  $str = "";

  $length = 32;

  for ($i = 0; $i < $length; $i++) {

    $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);

  }

  // 随机字符串

  return $str;

}

Home_index();