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, //應用ID，固定  'mch_id' => $mch_id, //商戶號，固定  'nonce_str' => $nonce_str, //隨機字符串  'op_user_id' => $op_user_id, //操作員  'out_refund_no' => $out_refund_no, //商戶內部唯一退款單號  'out_trade_no' => $out_trade_no, //商戶訂單號,pay_sn碼 1.1二選一,微信生成的訂單號，在支付通知中有返回  // 'transaction_id'=>'1',//微信訂單號 1.2二選一,商戶側傳給微信的訂單號  'refund_fee' => $refund_fee, //退款金額  'total_fee' => $total_fee, //總金額  'sign' => $ref//簽名  );  $url = "https://api.mch.weixin.qq.com/secapi/pay/refund";  ; //微信退款地址，post請求  $xml = arrayToXml($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); //證書檢查  if ($useCert == true) {    // 設置證書    curl_setopt($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);  // 返回結果0的時候能只能表明程序是正常返回不一定說明退款成功而已  if ($xml) {    curl_close($ch);    // 把xml轉化成數組    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);    // 錯誤的時候返回錯誤碼。    $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);  }  // 隨機字符串  return $str;}Home_index();