1.申请开通小程序支付，我们正式开通的微信支付是在微信公众平台上，我们需要绑定之前的微信商户平台即可，这一点不过多强调
2.小程序支付开发步骤
（1）、统一下单
大家看到微信的统一下单接口密密麻麻的一大堆参数，千万不要害怕，有问题解决就是了。
<?php //微信支付向外暴露的支付接口 public function pay() { $result = $this->weChatPay(); return $result; } //请求微信统一下单接口 private function weChatPay() { $param = array( \'appid\' => $this->APPID,//小程序id \'mch_id\'=> $this->MCHID,//商户id \'spbill_create_ip\'=>$_SERVER[\'REMOTE_ADDR\'],//终端ip \'notify_url\'=>$this->APPURL, //回调通知地址 \'nonce_str\'=> $this->createNoncestr(),//随机字符串 \'out_trade_no\'=>$this->outTradeNo,//商户订单编号 \'total_fee\'=>floatval($this->totalFee), //总金额 \'openid\'=>$this->openid,//用户openid \'trade_type\'=>$this->TRADETYPE,//交易类型 \'body\' =>$this->BODY, //商品信息 ); //通过签名算法计算得出的签名值，详见签名生成算法 $param[\'sign\'] = $this->getSign($param); //将数组内容转为xml格式，向微信发出请求 $xmlData = $this->arrayToXml($param); $xml_result = $this->postXmlCurl($xmlData,\'https://api.mch.weixin.qq.com/pay/unifiedorder\',60); $result = $this->xmlToArray($xml_result); return $result; // var_dump($result); /* * array(9) { ["return_code"]=> string(7) "SUCCESS" ["return_msg"]=> string(2) "OK" ["appid"]=> string(18) "wx2d4fefcfe1a39c9b" ["mch_id"]=> string(10) "1420537902" ["nonce_str"]=> string(16) "JASf0yXVuPknKm2J" ["sign"]=> string(32) "BE3CF30459D01660BB9AB2DE0AD023CE" ["result_code"]=> string(7) "SUCCESS" ["prepay_id"]=> string(36) "wx29154208585459f31c6875691178935371" ["trade_type"]=> string(5) "JSAPI" } } /* * 对要发送到微信统一下单接口的数据进行签名 */ protected function getSign($Obj){ foreach ($Obj as $k => $v){ $param[$k] = $v; } //签名步骤一：按字典序排序参数 ksort($param); $String = $this->formatBizQueryParaMap($param, false); //签名步骤二：在string后加入KEY $String = $String."&key=".$this->KEY; //签名步骤三：MD5加密 $String = md5($String); //签名步骤四：所有字符转为大写 $result_ = strtoupper($String); return $result_; } /* *排序并格式化参数方法，签名时需要使用 */ protected function formatBizQueryParaMap($paraMap, $urlencode) { $buff = ""; ksort($paraMap); foreach ($paraMap as $k => $v) { if($urlencode) { $v = urlencode($v); } //$buff .= strtolower($k) . "=" . $v . "&"; $buff .= $k . "=" . $v . "&"; } $reqPar = ""; if (strlen($buff) > 0) { $reqPar = substr($buff, 0, strlen($buff)-1); } return $reqPar; } /* * 生成随机字符串方法 */ protected function createNoncestr($length = 32 ){ $chars = "abcdefghijklmnopqrstuvwxyz0123456789"; $str =""; for ( $i = 0; $i < $length; $i++ ) { $str.= substr($chars, mt_rand(0, strlen($chars)-1), 1); } return $str; } //数组转字符串方法 protected function arrayToXml($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 $xml; } //将xml字符串转换为数组 protected static function xmlToArray($xml){ $array_data = json_decode(json_encode(simplexml_load_string($xml, \'SimpleXMLElement\', LIBXML_NOCDATA)), true); return $array_data; } //发送xml请求方法 private static function postXmlCurl($xml, $url, $second = 30) { $ch = curl_init(); //设置超时 curl_setopt($ch, CURLOPT_TIMEOUT, $second); curl_setopt($ch, CURLOPT_URL, $url); curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE); curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE); //严格校验 //设置header curl_setopt($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, $xml); curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 20); curl_setopt($ch, CURLOPT_TIMEOUT, 40); set_time_limit(0); //运行curl $data = curl_exec($ch); //返回结果 if ($data) { curl_close($ch); return $data; } else { $error = curl_errno($ch); curl_close($ch); throw new WxPayException("curl出错，错误码:$error"); } }