微信小程序支付功能 php后台对接完整代码分享

 /* 
 调起微信支付 
 @param 支付价格，不填写默认为1分钱 
*/ 
function pay(total_fee) { 
 
 var total_fee = total_fee; 
 wx.login({ 
 success: res => { 
 
 //code 用于获取openID的条件之一 
 var code = res.code; 
 wx.request({ 
 url: '后台地址/index.php', 
 method: "POST", 
 data: { 
  total_fee:total_fee, 
  code: code, 
 }, 
 header: { 
  'content-type': 'application/x-www-form-urlencoded' // 默认值 
 }, 
 success: function (res) { //后端返回的数据 
  var data = res.data; 
  console.log(data); 
  console.log(data["timeStamp"]); 
  wx.requestPayment({ 
  timeStamp: data['timeStamp'], 
  nonceStr: data['nonceStr'], 
  package: data['package'], 
  signType: data['signType'], 
  paySign: data['paySign'], 
  success: function (res) { 
  wx.showModal({ 
  title: '支付成功', 
  content: '', 
  }) 
  }, 
  fail: function (res) { 
  console.log(res); 
  } 
  }) 
 } 
 }); 
 
 
 } 
 }) 
 
} 

FromXml($xml); 
 if($result['return_code'] == 'SUCCESS' && $result['result_code'] == 'SUCCESS'){ 
  //回调逻辑处理。。。 
  
  
  //返回给微信的参数 
  $data['RETURN_CODE'] = 'SUCCESS'; 
  $data['RETURN_MSG'] = 'OK'; 
 
 
 }else{ 
  $data['RETURN_CODE'] = 'FAIL'; 
  $data['RETURN_MSG'] = 'NO'; 
 } 
 //返回给微信 
 $xml = self::arrtoxml($data); 
 echo $xml; 
 } 
 
 /** 
 * [arrtoxml 格式化返回给微信的数据格式] 
 * @Author zhengmingzhou 
 * @DateTime 2018-05-22 
 * @param [type] $arr [description] 
 * @return [type]  [description] 
 */ 
 private function arrtoxml( $arr ){ 
 if(!$arr){ 
  return ''; 
 }else{ 
  $xml = ""; 
  foreach ($arr as $key=>$val) 
  { 
  if (is_numeric($val)){ 
   $xml.="<".$key.">".$val.""; 
  }else{ 
   $xml.="<".$key.">"; 
  } 
  } 
  $xml.=""; 
  return $xml; 
 } 
 } 
 
//微信支付 
public function pay(){ 
 //获取openid 
 if(I("post.code")) 
 { //用code获取openid 
  $code=I("post.code"); 
  $WX_APPID = '';//appid 
  $WX_SECRET = '';//AppSecret 
  $url = "https://api.weixin.qq.com/sns/jscode2session?appid=" . $WX_APPID . "&secret=" . $WX_SECRET . "&js_code=" . $code . "&grant_type=authorization_code"; 
  $infos = json_decode(file_get_contents($url)); 
  $openid = $infos->openid; 
 } 
 if(I("post.total_fee")) 
 { 
  $total_fee=I("post.total_fee"); 
 } 
 else 
 { 
  $total_fee=0.01; 
 } 
 
 $fee = 0.01;//举例充值0.01 
 $appid = '';//appid 
 $body =  '标题'; 
 $mch_id = ''; //商户号 
 $nonce_str = $this->nonce_str();//随机字符串 
 $notify_url = ''; //回调的url【自己填写】 
 $openid = $openid; 
 $out_trade_no = $this->order_number();//商户订单号 
 $spbill_create_ip = '';//服务器的ip【自己填写】; 
 $total_fee = $fee*100;//这里需要*100 
 $trade_type = 'JSAPI';//交易类型 默认 
 
 
 //这里是按照顺序的 因为下面的签名是按照顺序 排序错误 肯定出错 
 $post['appid'] = $appid; 
 $post['body'] = $body; 
 $post['mch_id'] = $mch_id; 
 $post['nonce_str'] = $nonce_str;//随机字符串 
 $post['notify_url'] = $notify_url; 
 $post['openid'] = $openid; 
 $post['out_trade_no'] = $out_trade_no; 
 $post['spbill_create_ip'] = $spbill_create_ip;//终端的ip 
 $post['total_fee'] = $total_fee;//总金额 
 $post['trade_type'] = $trade_type; 
 $sign = $this->sign($post);//签名 
 $post_xml = ' 
  '.$appid.' 
  '.$body.' 
  '.$mch_id.' 
  '.$nonce_str.' 
  '.$notify_url.' 
  '.$openid.' 
  '.$out_trade_no.' 
  '.$spbill_create_ip.' 
  '.$total_fee.' 
  '.$trade_type.' 
  '.$sign.' 
  '; 
 
 
 //print_r($post_xml);die; 
 //统一接口prepay_id 
 $url = 'https://api.mch.weixin.qq.com/pay/unifiedorder'; 
 $xml = $this->http_request($url,$post_xml); 
 
 $array = $this->xml($xml);//全要大写 
 
 
 //print_r($array); 
 if($array['RETURN_CODE'] == 'SUCCESS' && $array['RESULT_CODE'] == 'SUCCESS'){ 
 $time = time(); 
 $tmp='';//临时数组用于签名 
 $tmp['appId'] = $appid; 
 $tmp['nonceStr'] = $nonce_str; 
 $tmp['package'] = 'prepay_id='.$array['PREPAY_ID']; 
 $tmp['signType'] = 'MD5'; 
 $tmp['timeStamp'] = "$time"; 
 
 
 $data['state'] = 200; 
 $data['timeStamp'] = "$time";//时间戳 
 $data['nonceStr'] = $nonce_str;//随机字符串 
 $data['signType'] = 'MD5';//签名算法，暂支持 MD5 
 $data['package'] = 'prepay_id='.$array['PREPAY_ID'];//统一下单接口返回的 prepay_id 参数值，提交格式如：prepay_id=* 
 $data['paySign'] = $this->sign($tmp);//签名,具体签名方案参见微信公众号支付帮助文档; 
 $data['out_trade_no'] = $out_trade_no; 
 
 
 }else{ 
 $data['state'] = 0; 
 $data['text'] = "错误"; 
 $data['RETURN_CODE'] = $array['RETURN_CODE']; 
 $data['RETURN_MSG'] = $array['RETURN_MSG']; 
 } 
 
 
 echo json_encode($data); 
} 

 
//随机32位字符串 
private function nonce_str(){ 
 $result = ''; 
 $str = 'QWERTYUIOPASDFGHJKLZXVBNMqwertyuioplkjhgfdsamnbvcxz'; 
 for ($i=0;$i<32;$i++){ 
 $result .= $str[rand(0,48)]; 
 } 
 return $result; 
} 
 
 
//生成订单号 
private function order_number($openid){ 
 //date('Ymd',time()).time().rand(10,99);//18位 
 return md5($openid.time().rand(10,99));//32位 
} 
 
 
//签名 $data要先排好顺序 
private function sign($data){ 
 $stringA = ''; 
 foreach ($data as $key=>$value){ 
 if(!$value) continue; 
 if($stringA) $stringA .= '&'.$key."=".$value; 
 else $stringA = $key."=".$value; 
 } 
 $wx_key = '';//申请支付后有给予一个商户账号和密码，登陆后自己设置的key 
 $stringSignTemp = $stringA.'&key='.$wx_key; 
 return strtoupper(md5($stringSignTemp)); 
} 
 
 
//curl请求 
public function http_request($url,$data = null,$headers=array()) 
{ 
 $curl = curl_init(); 
 if( count($headers) >= 1 ){ 
 curl_setopt($curl, CURLOPT_HTTPHEADER, $headers); 
 } 
 curl_setopt($curl, CURLOPT_URL, $url); 
 
 
 curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE); 
 curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, FALSE); 
 
 
 if (!empty($data)){ 
 curl_setopt($curl, CURLOPT_POST, 1); 
 curl_setopt($curl, CURLOPT_POSTFIELDS, $data); 
 } 
 curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1); 
 $output = curl_exec($curl); 
 curl_close($curl); 
 return $output; 
} 
 
 
//获取xml 
private function xml($xml){ 
 $p = xml_parser_create(); 
 xml_parse_into_struct($p, $xml, $vals, $index); 
 xml_parser_free($p); 
 $data = ""; 
 foreach ($index as $key=>$value) { 
 if($key == 'xml' || $key == 'XML') continue; 
 $tag = $vals[$value[0]]['tag']; 
 $value = $vals[$value[0]]['value']; 
 $data[$tag] = $value; 
 } 
 return $data; 
} 
 
}