微信支付分好几种支付场景，1、微信公众号内支付、2、微信扫码支付、3、H5支付（微信浏览器之外的其他浏览器）4、小程序支付、5、APP支付（第三方应用调起微信支付）、6、 刷卡支付（收银员用扫码设备扫描用户的二维码）。下面我们来讲解一下微信公众号支付的开发流程，包括简单的代码测试。
一、前期准备工作
1、申请一个认证服务号，并且开通支付功能
2、在公众号后台设置好网页授权域名，微信商户后台设置好支付授权目录
这两步是整个公众号支付流程的关键步骤，确保正确设置。如果不清楚怎么设置，这一步可以先自行度娘。
3、备案的域名+服务器（这个是必备的）
二、微信公众号支付开发流程
1、根据微信支付文档封装支付参数，调用微信支付统一下单接口向微信服务器发起请求，返回预支付交易会话标识。微信文档链接
2、封装JS支付参数，调用微信浏览器内置WeixinJSBridge对象，直接调起微信支付。
三、代码开发流程
前面粗略讲解了微信公众号支付的开发流程，理解起来应该是相对简单。下面是示例代码(只是测试代码，不要用于生产环境)：
1、第一步先获取用户openid，openid是公众号支付的一个重要参数，这里我们用微信网页授权接口来获取用户openid。
需要设置好网页域名授权，前期准备工作的第二步
微信页面授权类 thirdAuth.class.php1
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75<?php
class ThirdAuth{
private $code_url = 'https://open.weixin.qq.com/connect/oauth2/authorize?appid=%s&redirect_uri=%s&response_type=code&scope=%s&state=%s#wechat_redirect';
private $access_token_url = 'https://api.weixin.qq.com/sns/oauth2/access_token?appid=%s&secret=%s&code=%s&grant_type=authorization_code';
private $redirect_url;
private $appid;
private $appsecret;
function __construct($appid, $appsecret, $redirect_url){
$this->appid = $appid;
$this->appsecret = $appsecret;
$this->redirect_url = $redirect_url;
}
public function authCode($state = ''){
$makeUrl = $this->makeCodeUrl($this->code_url, $this->appid, urlencode($this->redirect_url), 'snsapi_base', $state);
header('Location:'.$makeUrl);
return;
}
function getCode($code, $state = ''){
$openid = $this->getOpenid($code);
if(empty($openid)){
$this->authCode($state);
}
return $openid;
}
public function getOpenid($code){
$makeUrl = $this->makeAccessTokenUrl($this->access_token_url, $this->appid, $this->appsecret, $code);
$result = $this->http_post($makeUrl);
if(!empty($result['openid'])){
return $result['openid'];
}else{
return;
}
}
public function makeCodeUrl($url, $appid, $redirect_uri, $scope, $state){
return sprintf($url, $appid, $redirect_uri, $scope, $state);
}
public function makeAccessTokenUrl($url, $appid, $secret, $code){
return sprintf($url, $appid, $secret, $code);
}
//发送post请求
function http_post($url, $param) {
$header [] = "content-type: application/json; charset=UTF-8";
$ch = curl_init ();
curl_setopt ( $ch, CURLOPT_URL, $url );
curl_setopt ( $ch, CURLOPT_CUSTOMREQUEST, "POST" );
curl_setopt ( $ch, CURLOPT_SSL_VERIFYPEER, FALSE );
curl_setopt ( $ch, CURLOPT_SSL_VERIFYHOST, FALSE );
curl_setopt ( $ch, CURLOPT_HTTPHEADER, $header );
curl_setopt ( $ch, CURLOPT_USERAGENT, 'Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)' );
curl_setopt ( $ch, CURLOPT_FOLLOWLOCATION, 1 );
curl_setopt ( $ch, CURLOPT_AUTOREFERER, 1 );
curl_setopt ( $ch, CURLOPT_POSTFIELDS, $param );
curl_setopt ( $ch, CURLOPT_RETURNTRANSFER, true );
$res = curl_exec ( $ch );
curl_close ( $ch );
$res = json_decode ( $res, true );
return $res;
}
}
？>
测试脚本 test.php1
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23<?php
//引入微信页面授权类
include 'thirdAuth.class.php';
//公众号appid
$appid = 'APPID';
//公众号appsecret
$appsecret = 'APPSECRET';
//页面回调域名
$redirect_url = 'http://whatcode.cn/test.php';
$thirdAuth = new ThirdAuth($appid, $appsecret, $redirect_url);
$state = 'test';
if(isset($_GET['code']) && !empty($_GET['code'])){
$code = $_GET['code'];
$state = $_GET['state'];
$openid = $thirdAuth->getCode($code, $state);
//打印openid看看输出结果
print_r($openid);
}else{
$thirdAuth->authCode($state);
}
?>
2、调用微信统一下单接口，获取微信预支付交易会话标识。
调用统一下单接口类 wxpay.class.php1
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166<?php
/**
* 微信支付
*/
class WxPay
{
private $apiUrl = 'https://api.mch.weixin.qq.com/pay/unifiedorder';
private $key;
private $mch_id;
private $appid;
private $openid;
private $nonce_str;
private $body;
private $out_trade_no;
private $total_fee;
private $spbill_create_ip;
private $notify_url;
private $trade_type;
function __construct($attributes)
{
$this->key = $attributes['key'];
$this->mch_id = $attributes['mch_id'];
$this->appid = $attributes['appid'];
$this->openid = $attributes['openid'];
$this->body = $attributes['body'];
$this->total_fee = $attributes['total_fee'];
$this->trade_type = $attributes['trade_type'];
$this->notify_url = $attributes['notify_url'];
}
//发送post请求
function http_post($url, $param) {
$header [] = "content-type: application/json; charset=UTF-8";
$ch = curl_init ();
curl_setopt ( $ch, CURLOPT_URL, $url );
curl_setopt ( $ch, CURLOPT_CUSTOMREQUEST, "POST" );
curl_setopt ( $ch, CURLOPT_SSL_VERIFYPEER, FALSE );
curl_setopt ( $ch, CURLOPT_SSL_VERIFYHOST, FALSE );
curl_setopt ( $ch, CURLOPT_HTTPHEADER, $header );
curl_setopt ( $ch, CURLOPT_USERAGENT, 'Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)' );
curl_setopt ( $ch, CURLOPT_FOLLOWLOCATION, 1 );
curl_setopt ( $ch, CURLOPT_AUTOREFERER, 1 );
curl_setopt ( $ch, CURLOPT_POSTFIELDS, $param );
curl_setopt ( $ch, CURLOPT_RETURNTRANSFER, true );
$res = curl_exec ( $ch );
curl_close ( $ch );
//$res = json_decode ( $res, true );
return $res;
}
//数组转换为xml格式
function arrayToXml($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 $xml;
}
//将XML转为数组
function xmlToArray($xml)
{
//禁止引用外部xml实体
libxml_disable_entity_loader(true);
$values = json_decode(json_encode(simplexml_load_string($xml, 'SimpleXMLElement', LIBXML_NOCDATA)), true);
return $values;
}
//支付参数签名
function paySign($array, $key){
ksort($array);
$str = '';
foreach($array as $k => $value){
$str .= $k.'='.$value.'&';
}
$str .= "key=".$key;
$str = strtoupper(md5($str));
return $str;
}
//生成随机字符串
function get_rand_char($length = 6, $type = 1) {
$str1 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz";
$str2 = "0123456789";
$strLength1 = 61;
$strLength2 = 9;
$res = '';
if($type == 1){
for($i = 0; $i < $length; $i ++) {
$res .= $str1 [rand ( 0, $strLength1 )];
}
}else{
for($i = 0; $i < $length; $i ++) {
$res .= $str2 [rand ( 0, $strLength2 )];
}
}
return $res;
}
//获取IP
function get_client_ip() {
$ip = $_SERVER['REMOTE_ADDR'];
if (isset($_SERVER['HTTP_CLIENT_IP']) && preg_match('/^([0-9]{1,3}\.){3}[0-9]{1,3}$/', $_SERVER['HTTP_CLIENT_IP'])) {
$ip = $_SERVER['HTTP_CLIENT_IP'];
} elseif(isset($_SERVER['HTTP_X_FORWARDED_FOR']) AND preg_match_all('#\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}#s', $_SERVER['HTTP_X_FORWARDED_FOR'], $matches)) {
foreach ($matches[0] AS $xip) {
if (!preg_match('#^(10|172\.16|192\.168)\.#', $xip)) {
$ip = $xip;
break;
}
}
}
return $ip == '::1' ? '127.0.0.1' : $ip;
}
function prepare(){
$payConfig = [
'mch_id' => $this->mch_id,
'appid' => $this->appid,
'openid' => $this->openid,
'nonce_str' => $this->get_rand_char(32,2),
'body' => $this->body,
'out_trade_no' => date('YmdHis').$this->get_rand_char(6,1),
'total_fee' => $this->total_fee,
'spbill_create_ip' => $this->get_client_ip(),
'notify_url' => $this->notify_url,
'trade_type' => $this->trade_type,
];
$sign = $this->paySign($payConfig, $this->key);
$payConfig['sign'] = $sign;
$payXML = $this->arrayToXml($payConfig);
$result = $this->http_post($this->apiUrl, $payXML);
return $this->xmlToArray($result);
}
function configForPayment($prepayId){
$jsPayConfig = [
'appId' => $this->appid,
'timeStamp' => strval(time()),
'nonceStr' => $this->get_rand_char(32,2),
'package' => "prepay_id=$prepayId",
'signType' => 'MD5',
];
$jsPayConfig['paySign'] = $this->paySign($jsPayConfig, $this->key);
return json_encode($jsPayConfig);
}
}
测试脚本 test.php1
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53<?php
//引入微信页面授权类
include 'thirdAuth.class.php';
include 'wxpay.class.php';
//公众号appid
$appid = 'APPID';
//公众号appsecret
$appsecret = 'APPSECRET';
//页面回调域名
$redirect_url = 'http://whatcode.cn/test.php';
$thirdAuth = new ThirdAuth($appid, $appsecret, $redirect_url);
$state = 'test';
if(isset($_GET['code']) && !empty($_GET['code'])){
$code = $_GET['code'];
$state = $_GET['state'];
$openid = $thirdAuth->getCode($code, $state);
}else{
$thirdAuth->authCode($state);
exit;
}
//商户号
$mch_id = 'MCH_ID';
//API KEY
$key = 'KEY';
//支付回调地址
$notify_url = 'http://whatcode.cn/notify.php';
//商品描述
$body = '微信测试';
//商品价格
$total_fee = '100';
//微信支付类型
$trade_type = 'JSAPI';
//支付配置参数
$attributes = [
'mch_id' => $mch_id,
'key' => $key,
'appid' => $appid,
'openid' => $openid,
'body' => $body,
'total_fee' => $total_fee,
'notify_url' => $notify_url,
'trade_type' => $trade_type,
];
$wxpay = new WxPay($attributes);
$result = $wxpay->prepare();
//打印输出$result
print_r($result);
?>
3、封装JS支付参数，调用微信浏览器内置WeixinJSBridge对象，直接调起微信支付。
测试脚本 test.php1
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99<?php
//引入微信页面授权类
include 'thirdAuth.class.php';
include 'wxpay.class.php';
//公众号appid
$appid = 'APPID';
//公众号appsecret
$appsecret = 'APPSECRET';
//页面回调域名
$redirect_url = 'http://whatcode.cn/test.php';
$thirdAuth = new ThirdAuth($appid, $appsecret, $redirect_url);
$state = 'test';
if(isset($_GET['code']) && !empty($_GET['code'])){
$code = $_GET['code'];
$state = $_GET['state'];
$openid = $thirdAuth->getCode($code, $state);
}else{
$thirdAuth->authCode($state);
exit;
}
//商户号
$mch_id = 'MCH_ID';
//API KEY
$key = 'KEY';
//支付回调地址
$notify_url = 'http://whatcode.cn/notify.php';
//商品描述
$body = '微信测试';
//商品价格
$total_fee = '100';
//微信支付类型
$trade_type = 'JSAPI';
//支付配置参数
$attributes = [
'mch_id' => $mch_id,
'key' => $key,
'appid' => $appid,
'openid' => $openid,
'body' => $body,
'total_fee' => $total_fee,
'notify_url' => $notify_url,
'trade_type' => $trade_type,
];
$wxpay = new WxPay($attributes);
$result = $wxpay->prepare();
if ($result['return_code'] == 'SUCCESS' && $result['result_code'] == 'SUCCESS'){
$prepayId = $result['prepay_id'];
$jsapi = $wxpay->configForPayment($prepayId);
//调用微信WeixinJSBridge对象
echo <<<EOT
<html>
<head>
<meta http-equiv="content-type" content="text/html;charset=utf-8"/>
<meta name="viewport" content="width=device-width, initial-scale=1"/>
<title>微信支付-支付</title>
<script type="text/javascript">
function jsApiCall()
{
WeixinJSBridge.invoke(
'getBrandWCPayRequest',
{$jsapi},
function(res){
if(res.err_msg == "get_brand_wcpay_request:ok"){
alert('支付成功');
}else{
alert('支付失败')；
}
}
);
}
function callpay()
{
if (typeof WeixinJSBridge == "undefined"){
if( document.addEventListener ){
document.addEventListener('WeixinJSBridgeReady', jsApiCall, false);
}else if (document.attachEvent){
document.attachEvent('WeixinJSBridgeReady', jsApiCall);
document.attachEvent('onWeixinJSBridgeReady', jsApiCall);
}
}else{
jsApiCall();
}
}
</script>
</head>
<body onload="callpay()"></body>
</html>
EOT;
}else{
exit('调用统一下单接口出错');
}
?>
到这里应该可以正常调起微信支付了。
四、总结
1、如果没能正常调起微信支付，最好是对照着微信的错误码来查找原因，尽量避免配置上的失误。
2、支付目录如果没设置正确，是没有错误码提示的，一定要看清楚你的支付路由的上一级目录就是支付目录。
3、根据我的示例代码，一步一步来，应该能成功调起微信支付，当然这只是示例代码，代码逻辑还不够严谨，这里只是用来讲解微信支付的开发流程。后面我会整理一个通用版的微信支付类。
