在php中实现微信支付，我们需要准备设置以下东西：

1、appid（微信开放平台上的应用id）

2、mch_id（微信申请成功之后邮件中的商户id）

3、notify_url（支付成功后的回调地址）

4、api_key（在微信商户平台上自己设定的api密钥 32位）

5、apiclient_cert.pem 和 apiclient_key.pem 证书

接下来直接上代码（可复制粘贴，修改以上的参数及可使用）：

<?php
namespace app\api\controller;
use think\Db;class Wxpay{/*微信支付配置参数*/private $config = array('appid' => "你的微信开放平台上的应用id",    /*微信开放平台上的应用id*/'mch_id' => "你的微信申请成功之后邮件中的商户id",   /*微信申请成功之后邮件中的商户id*/'api_key' => "你的在微信商户平台上自己设定的api密钥",    /*在微信商户平台上自己设定的api密钥 32位*/'notify_url' => '回调地址',);//微信支付下单public function wxpay($body,$orderid, $out_trade_no, $total_fee, $type){$url = "https://api.mch.weixin.qq.com/pay/unifiedorder";$data["appid"]            = $this->config["appid"];$data["body"]             = '艺商城-'.$body;$data["mch_id"]           = $this->config['mch_id'];$data["nonce_str"]        = $this->createNoncestr();$data["notify_url"]       = $this->config["notify_url"];$data['trade_type']       = 'APP';$data["total_fee"]        = "1";//"$total_fee"$data["out_trade_no"]     = $out_trade_no;$data["spbill_create_ip"] = $this->get_client_ip();$sign                     = $this->getSign($data);$data["sign"]             = $sign;$xml      = $this->arrayToXml($data);$response = $this->postXmlCurl($xml, $url);$response = $this->xmlToArray($response);$response = $this->two_sign($response, $data["nonce_str"]);//返回数据echo json_encode(['status'=>1,'indo'=>'success','orderid'=>$orderid,'data'=>$response]);}//微信支付回调地址--商品支付public function wxNotifyUrl(){$type = 3;$this->payCommom($type);}/*** [payCommom 充值公共方法]* @param  [type] $type []* @return [type]       [description]*/public function payCommom($type){$xml_data = file_get_contents('php://input');$re = $this->wx_verification($xml_data);$flow_sn = $re['transaction_id'];//获取流水号if($re['code'] == 1){$data  = $this->xmlToArray($xml_data);// 启动事务Db::startTrans();try{#你的订单业务逻辑....// 提交事务Db::commit(); } catch (\Exception $e) {// 回滚事务Db::rollback();}}}echo "<xml><return_code><![CDATA[SUCCESS]]></return_code><return_msg><![CDATA[OK]]></return_msg></xml>";}/*** 微信支付退款* $pay_sn      支付单号* $total_fee   订单金额* $refund_fee  退款金额*/public function wxrefundOrder($pay_sn, $total_fee, $refund_fee){$url = "https://api.mch.weixin.qq.com/secapi/pay/refund";$data["appid"]            = $this->config["appid"];$data["mch_id"]           = $this->config['mch_id'];$data["nonce_str"]        = $this->createNoncestr();$data['out_trade_no']     = $pay_sn;$data['out_refund_no']    = $pay_sn;$data["total_fee"]        = intval($total_fee * 100);$data["refund_fee"]       = intval($refund_fee * 100);$sign                     = $this->getSign($data);$data["sign"]             = $sign;$xml      = $this->arrayToXml($data);$response = $this->postXmlCurl($xml, $url);$response = $this->xmlToArray($response);  if ($response['return_code'] == 'SUCCESS' && $response['refund_id']) {return ['code'=>1,'refund_id'    => $response['refund_id']];}else{return ['code'=>0,'err_code_des' => $response['err_code_des']];}}/*** [order_record 订单记录]* @return [type] [description]*/public function order_record($orderid, $unionid, $title, $price, $user_money){$record['orderid'] = $orderid; $record['unionid'] = $unionid; $record['title'] = $title; $record['price'] = $price;$record['money'] = $user_money;$record['addtime'] = time();Db::name('order_record')->insert($record);}//微信支付二次签名public function two_sign( $response = NULL, $nonce_str){if( $response != NULL && $response['return_code'] != 'SUCCESS'){return [];}else{//接收微信返回的数据,传给APP!$arr =array('appid'     => $this->config["appid"],'partnerid' => $this->config['mch_id'],'prepayid'  => $response['prepay_id'],'package'   => 'Sign=WXPay','noncestr'  => $nonce_str,'timestamp' => time(),);//第二次生成签名$sign = $this->getSign($arr);$arr['sign'] = $sign;return $arr;}}//微信支付签名public function getSign($Obj){foreach ($Obj as $k => $v){$Parameters[$k] = $v;}//签名步骤一：按字典序排序参数ksort($Parameters);$String = $this->formatBizQueryParaMap($Parameters, false);// echo '【string1】：'.$String.'</br>';//签名步骤二：在string后加入KEY$String = $String."&key=".$this->config['api_key'];// echo "【string2】".$String."</br>";//签名步骤三：MD5加密$String = md5($String);// echo "【string3】 ".$String."</br>";//签名步骤四：所有字符转为大写$result_ = strtoupper($String);// echo "【result】 ".$result_."</br>";return $result_;}/***  作用：产生随机字符串，不长于32位*/public function createNoncestr( $length = 32 ){$chars = "abcdefghijklmnopqrstuvwxyz0123456789"; $str ="";for ( $i = 0; $i < $length; $i++ )  { $str.= substr($chars, mt_rand(0, strlen($chars)-1), 1); } return $str;}/*获取当前服务器的IP*/public function get_client_ip(){if ($_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 $cip;}//数组转xmlpublic function arrayToXml($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 $xml;}/***  作用：将xml转为array*/public function xmlToArray($xml){  //将XML转为array       $array_data = json_decode(json_encode(simplexml_load_string($xml, 'SimpleXMLElement', LIBXML_NOCDATA)), true);   return $array_data;}/***  作用：以post方式提交xml到对应的接口url*/public function postXmlCurl($xml,$url,$second=30){  //初始化curl       $ch = curl_init();//设置超时curl_setopt($ch, CURLOPT_TIMEOUT, $second);  //这里设置代理，如果有的话//curl_setopt($ch,CURLOPT_PROXY, '8.8.8.8');//curl_setopt($ch,CURLOPT_PROXYPORT, 8080);curl_setopt($ch,CURLOPT_URL, $url);curl_setopt($ch,CURLOPT_SSL_VERIFYPEER,FALSE);curl_setopt($ch,CURLOPT_SSL_VERIFYHOST,2);//设置headercurl_setopt($ch, CURLOPT_HEADER, FALSE);  //要求结果为字符串且输出到屏幕上curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);//post提交方式curl_setopt($ch, CURLOPT_POST, TRUE);curl_setopt($ch, CURLOPT_POSTFIELDS, $xml);//默认格式为PEM，可以注释curl_setopt($ch,CURLOPT_SSLCERTTYPE,'PEM');//退款证书curl_setopt($ch,CURLOPT_SSLCERT,PUBLIC_PATH.'/wx/apiclient_cert.pem');//默认格式为PEM，可以注释curl_setopt($ch,CURLOPT_SSLKEYTYPE,'PEM');//退款证书curl_setopt($ch,CURLOPT_SSLKEY,PUBLIC_PATH.'/wx/apiclient_key.pem');//运行curl$data = curl_exec($ch);//返回结果if($data){curl_close($ch);return $data;}else{$error = curl_errno($ch);echo "curl出错，错误码:$error"."<br>";curl_close($ch);return false;}}/***  作用：格式化参数，签名过程需要使用*/public function formatBizQueryParaMap($paraMap, $urlencode){$buff = "";ksort($paraMap);foreach ($paraMap as $k => $v){if($urlencode){$v = urlencode($v);}$buff .= $k . "=" . $v . "&";}$reqPar;if (strlen($buff) > 0){$reqPar = substr($buff, 0, strlen($buff)-1);}return $reqPar;}//微信支付回调验证public function wx_verification($xml_data){$data = $this->xmlToArray($xml_data);$sign = $data['sign'];unset($data['sign']);if($sign == $this->getSign($data)){if ($data['result_code'] == 'SUCCESS') {$arr=['code'=>1];}else{$arr=['code'=>0,'msg'=>$data['return_msg']];}}else{$arr=['code'=>0,'msg'=>'签名验证失败']; }return $arr;}
}