开发微信支付需要认证服务号并且已经开通微信支付，获得微信支付商ID，设置apikey了的。

官方给了公众号支付的php源码SDK

但是这个SDK文件非常多，源码乱七八糟的，真的一开始接触的人拿着官方的SDK肯定踩坑。

而且还不知道最后能不能用。

我看到了一个作者写的源码，还不错，我简单进行优化了，只有200多行代码就可以实现公众号支付。

在开发之前，得先配置网页授权的域名和支付授权域名。

网页授权域名在公众号后台，接口权限找到网页获取用户基本信息处配置你的代码所在的目录，例如你的公众号支付代码放在www.baidu.com/pay/jspai.php

那么网页授权域名为：www.baidu.com/pay/

支付授权域名配置要登录商户平台

然后往下拉找到公众号支付

添加授权目录即可，授权目录也是你的代码所在目录。

接着就可以开发了

下面是代码，直接可以用。

header('Content-type:text/html; Charset=utf-8');

$mchid = '微信支付商户号';

$appid = '微信支付申请对应的公众号的APPID';

$appKey = '微信支付申请对应的公众号的APPSECRET';

$apiKey = 'API密钥'; //商户平台-帐户设置-安全设置-API安全-API密钥-设置API密钥

//①、获取用户openid

$wxPay = new WxpayService($mchid,$appid,$appKey,$apiKey);

$openId = $wxPay->GetOpenid(); //获取openid

if(!$openId) exit('获取openid失败');

//②、统一下单

$outTradeNo = uniqid(); //你自己的商品订单号

$payAmount = 0.01; //付款金额，单位:元

$orderName = 'test'; //订单标题

$notifyUrl = 'https://www.likeyunba.com/pay/notify.php'; //付款成功后的回调地址(不要有问号)

$payTime = time(); //付款时间

$jsApiParameters = $wxPay->createJsBizPackage($openId,$payAmount,$outTradeNo,$orderName,$notifyUrl,$payTime);

$jsApiParameters = json_encode($jsApiParameters);

?>

微信支付样例-支付

//调用微信JS api 支付

function jsApiCall()

{

WeixinJSBridge.invoke(

'getBrandWCPayRequest',

<?php echo $jsApiParameters; ?>,

function(res){

WeixinJSBridge.log(res.err_msg);

//alert(res.err_code+res.err_desc+res.err_msg);

if(res.err_msg == "get_brand_wcpay_request:ok"){

//支付成功跳转页面

window.location.href="http://www.likeyunba.com/pay/true.html";

}else{

//支付失败/或取消支付跳转页面

window.location.href="http://www.likeyunba.com/pay/false.html";

}

}

);

}

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();

}

}

该笔订单支付金额为<?php echo $payAmount?>元钱

header("Content-Type:text/html; charset=utf-8");

class WxpayService

{

protected $mchid;

protected $appid;

protected $appKey;

protected $apiKey;

public $data = null;

public function __construct($mchid, $appid, $appKey,$key)

{

$this->mchid = $mchid; //https://pay.weixin.qq.com 产品中心-开发配置-商户号

$this->appid = $appid; //微信支付申请对应的公众号的APPID

$this->appKey = $appKey; //微信支付申请对应的公众号的APP Key

$this->apiKey = $key; //https://pay.weixin.qq.com 帐户设置-安全设置-API安全-API密钥-设置API密钥

}

/**

* 通过跳转获取用户的openid，跳转流程如下：

* 1、设置自己需要调回的url及其其他参数，跳转到微信服务器https://open.weixin.qq.com/connect/oauth2/authorize

* 2、微信服务处理完成之后会跳转回用户redirect_uri地址，此时会带上一些参数，如：code

* @return 用户的openid

*/

public function GetOpenid()

{

//通过code获得openid

if (!isset($_GET['code'])){

//触发微信返回code码

$scheme = $_SERVER['HTTPS']=='on' ? 'https://' : 'http://';

$baseUrl = urlencode($scheme.$_SERVER['HTTP_HOST'].$_SERVER['PHP_SELF'].$_SERVER['QUERY_STRING']);

$url = $this->__CreateOauthUrlForCode($baseUrl);

Header("Location: $url");

exit();

} else {

//获取code码，以获取openid

$code = $_GET['code'];

$openid = $this->getOpenidFromMp($code);

return $openid;

}

}

/**

* 通过code从工作平台获取openid机器access_token

* @param string $code 微信跳转回来带上的code

* @return openid

*/

public function GetOpenidFromMp($code)

{

$url = $this->__CreateOauthUrlForOpenid($code);

$res = self::curlGet($url);

//取出openid

$data = json_decode($res,true);

$this->data = $data;

$openid = $data['openid'];

return $openid;

}

/**

* 构造获取open和access_toke的url地址

* @param string $code，微信跳转带回的code

* @return 请求的url

*/

private function __CreateOauthUrlForOpenid($code)

{

$urlObj["appid"] = $this->appid;

$urlObj["secret"] = $this->appKey;

$urlObj["code"] = $code;

$urlObj["grant_type"] = "authorization_code";

$bizString = $this->ToUrlParams($urlObj);

return "https://api.weixin.qq.com/sns/oauth2/access_token?".$bizString;

}

/**

* 构造获取code的url连接

* @param string $redirectUrl 微信服务器回跳的url，需要url编码

* @return 返回构造好的url

*/

private function __CreateOauthUrlForCode($redirectUrl)

{

$urlObj["appid"] = $this->appid;

$urlObj["redirect_uri"] = "$redirectUrl";

$urlObj["response_type"] = "code";

$urlObj["scope"] = "snsapi_base";

$urlObj["state"] = "STATE"."#wechat_redirect";

$bizString = $this->ToUrlParams($urlObj);

return "https://open.weixin.qq.com/connect/oauth2/authorize?".$bizString;

}

/**

* 拼接签名字符串

* @param array $urlObj

* @return 返回已经拼接好的字符串

*/

private function ToUrlParams($urlObj)

{

$buff = "";

foreach ($urlObj as $k => $v)

{

if($k != "sign") $buff .= $k . "=" . $v . "&";

}

$buff = trim($buff, "&");

return $buff;

}

/**

* 统一下单

* @param string $openid 调用【网页授权获取用户信息】接口获取到用户在该公众号下的Openid

* @param float $totalFee 收款总费用 单位元

* @param string $outTradeNo 唯一的订单号

* @param string $orderName 订单名称

* @param string $notifyUrl 支付结果通知url 不要有问号

* @param string $timestamp 支付时间

* @return string

*/

public function createJsBizPackage($openid, $totalFee, $outTradeNo, $orderName, $notifyUrl, $timestamp)

{

$config = array(

'mch_id' => $this->mchid,

'appid' => $this->appid,

'key' => $this->apiKey,

);

$orderName = iconv('GBK','UTF-8',$orderName);

$unified = array(

'appid' => $config['appid'],

'attach' => 'pay', //商家数据包，原样返回，如果填写中文，请注意转换为utf-8

'body' => $orderName,

'mch_id' => $config['mch_id'],

'nonce_str' => self::createNonceStr(),

'notify_url' => $notifyUrl,

'openid' => $openid, //rade_type=JSAPI，此参数必传

'out_trade_no' => $outTradeNo,

'spbill_create_ip' => '127.0.0.1',

'total_fee' => intval($totalFee * 100), //单位 转为分

'trade_type' => 'JSAPI',

);

$unified['sign'] = self::getSign($unified, $config['key']);

$responseXml = self::curlPost('https://api.mch.weixin.qq.com/pay/unifiedorder', self::arrayToXml($unified));

$unifiedOrder = simplexml_load_string($responseXml, 'SimpleXMLElement', LIBXML_NOCDATA);

if ($unifiedOrder === false) {

die('parse xml error');

}

if ($unifiedOrder->return_code != 'SUCCESS') {

die($unifiedOrder->return_msg);

}

if ($unifiedOrder->result_code != 'SUCCESS') {

die($unifiedOrder->err_code);

}

$arr = array(

"appId" => $config['appid'],

"timeStamp" => "$timestamp", //这里是字符串的时间戳，不是int，所以需加引号

"nonceStr" => self::createNonceStr(),

"package" => "prepay_id=" . $unifiedOrder->prepay_id,

"signType" => 'MD5',

);

$arr['paySign'] = self::getSign($arr, $config['key']);

return $arr;

}

public static function curlGet($url = '', $options = array())

{

$ch = curl_init($url);

curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

curl_setopt($ch, CURLOPT_TIMEOUT, 30);

if (!empty($options)) {

curl_setopt_array($ch, $options);

}

//https请求 不验证证书和host

curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);

curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);

$data = curl_exec($ch);

curl_close($ch);

return $data;

}

public static function curlPost($url = '', $postData = '', $options = array())

{

if (is_array($postData)) {

$postData = http_build_query($postData);

}

$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, $url);

curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

curl_setopt($ch, CURLOPT_POST, 1);

curl_setopt($ch, CURLOPT_POSTFIELDS, $postData);

curl_setopt($ch, CURLOPT_TIMEOUT, 30); //设置cURL允许执行的最长秒数

if (!empty($options)) {

curl_setopt_array($ch, $options);

}

//https请求 不验证证书和host

curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);

curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);

$data = curl_exec($ch);

curl_close($ch);

return $data;

}

public static function createNonceStr($length = 16)

{

$chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';

$str = '';

for ($i = 0; $i < $length; $i++) {

$str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);

}

return $str;

}

public static function arrayToXml($arr)

{

$xml = "";

foreach ($arr as $key => $val) {

if (is_numeric($val)) {

$xml .= "" . $val . "" . $key . ">";

} else

$xml .= "" . $key . ">";

}

$xml .= "";

return $xml;

}

public static function getSign($params, $key)

{

ksort($params, SORT_STRING);

$unSignParaString = self::formatQueryParaMap($params, false);

$signStr = strtoupper(md5($unSignParaString . "&key=" . $key));

return $signStr;

}

protected static function formatQueryParaMap($paraMap, $urlEncode = false)

{

$buff = "";

ksort($paraMap);

foreach ($paraMap as $k => $v) {

if (null != $v && "null" != $v) {

if ($urlEncode) {

$v = urlencode($v);

}

$buff .= $k . "=" . $v . "&";

}

}

$reqPar = '';

if (strlen($buff) > 0) {

$reqPar = substr($buff, 0, strlen($buff) - 1);

}

return $reqPar;

}

}

?>

notify.php

/**

* 原生支付(扫码支付)及公众号支付的异步回调通知

* 说明：需要在native.php或者jsapi.php中的填写回调地址。例如：http://www.xxx.com/wx/notify.php

* 付款成功后，微信服务器会将付款结果通知到该页面

*/

header('Content-type:text/html; Charset=utf-8');

$mchid = '微信支付商户号';

$appid = '公众号APPID';

$apiKey = 'API密钥';

$wxPay = new WxpayService($mchid,$appid,$apiKey);

$result = $wxPay->notify();

if($result){

//完成你的逻辑

//例如连接数据库，获取付款金额$result['cash_fee']，获取订单号$result['out_trade_no']，修改数据库中的订单状态等;

}else{

echo 'pay error';

}

class WxpayService

{

protected $mchid;

protected $appid;

protected $apiKey;

public function __construct($mchid, $appid, $key)

{

$this->mchid = $mchid;

$this->appid = $appid;

$this->apiKey = $key;

}

public function notify()

{

$config = array(

'mch_id' => $this->mchid,

'appid' => $this->appid,

'key' => $this->apiKey,

);

$postStr = $GLOBALS["HTTP_RAW_POST_DATA"];

$postObj = simplexml_load_string($postStr, 'SimpleXMLElement', LIBXML_NOCDATA);

if ($postObj === false) {

die('parse xml error');

}

if ($postObj->return_code != 'SUCCESS') {

die($postObj->return_msg);

}

if ($postObj->result_code != 'SUCCESS') {

die($postObj->err_code);

}

$arr = (array)$postObj;

unset($arr['sign']);

if (self::getSign($arr, $config['key']) == $postObj->sign) {

echo '';

return $arr;

}

}

/**

* 获取签名

*/

public static function getSign($params, $key)

{

ksort($params, SORT_STRING);

$unSignParaString = self::formatQueryParaMap($params, false);

$signStr = strtoupper(md5($unSignParaString . "&key=" . $key));

return $signStr;

}

protected static function formatQueryParaMap($paraMap, $urlEncode = false)

{

$buff = "";

ksort($paraMap);

foreach ($paraMap as $k => $v) {

if (null != $v && "null" != $v) {

if ($urlEncode) {

$v = urlencode($v);

}

$buff .= $k . "=" . $v . "&";

}

}

$reqPar = '';

if (strlen($buff) > 0) {

$reqPar = substr($buff, 0, strlen($buff) - 1);

}

return $reqPar;

}

}

简单说明：

1】新建jsapi.php，拷贝上面的代码，修改商户号、appid、appsecret、密钥即可，还有下面的回调地址，前面的域名需要换成你的nofity.php的地址。至于支付成功和支付失败跳转的页面按自己的需求修改即可。

要注意，订单标题不能为中文，否则会提示body参数错误什么的。

2】新建nofity.php

把上面的代码拷贝上去，修改商户号、appid、密钥即可。

上传到支付授权目录，然后访问jsapi.php页面测试。