解析微信支付的实现方法（.NET版）

 //判断是否网页授权，获取授权code,没有代表没有授权，构造网页授权获取code,并重新请求
 if (string.IsNullOrEmpty(Request.QueryString["code"]))
 {
 string redirectUrl = _weChatPaySerivce.GetAuthorizeUrl(account.AppId, account.RedquestUrl,
 "STATE" + "#wechat_redirect", "snsapi_base");
 return Redirect(redirectUrl);
 }

public string GetAuthorizeUrl(string appId, string redirectUrl, string state, string scope)
 {
 string url = string.Format("https://open.weixin.qq.com/connect/oauth2/authorize?appid={0}&redirect_uri={1}&response_type=code&scope={2}&state={3}",
 appId, HttpUtility.UrlEncode(redirectUrl), scope, state);
 /* 这一步发送之后，客户会得到授权页面，无论同意或拒绝，都会返回redirectUrl页面。
 * 如果用户同意授权，页面将跳转至 redirect_uri/?code=CODE&state=STATE。这里的code用于换取access_token（和通用接口的access_token不通用）
 * 若用户禁止授权，则重定向后不会带上code参数，仅会带上state参数redirect_uri?state=STATE
 */
 AppLog.Write("获取到授权url:", AppLog.LogMessageType.Debug); 
 return url;
 }

 public Tuple<string, string> GetOpenidAndAccessTokenFromCode(string appId, string code, string appSecret)
 {
 Tuple<string, string> tuple = null;
 try
 {
 string url = string.Format("https://api.weixin.qq.com/sns/oauth2/access_token?appid={0}&secret={1}&code={2}&grant_type=authorization_code", appId, appSecret, code);
 string result = WeChatPayHelper.Get(url);
 AppLog.Write("微信支付-获取openid和access_token 请求Url:" + url + "result:" + result, AppLog.LogMessageType.Debug);
 if (!string.IsNullOrEmpty(result))
 {
 var jd=Newtonsoft.Json.JsonConvert.DeserializeObject<Dictionary<string, string>>(result);
 tuple = new Tuple<string, string>(jd["openid"],jd["access_token"]);
 AppLog.Write("微信支付-获取openid和access_token成功", AppLog.LogMessageType.Debug);
 }
 }
 catch (Exception ex)
 {
 AppLog.Write("微信支付：获取openid和access_tokenu异常", AppLog.LogMessageType.Debug,ex);
 }
 return tuple;
 }

//创建支付应答对象
 RequestHandler packageReqHandler = new RequestHandler(null);
 //初始化
 packageReqHandler.Init();
 //时间戳
 string timeStamp = TenPayUtil.GetTimestamp();
 //随机字符串
 string nonceStr = TenPayUtil.GetNoncestr();
 //设置package订单参数 生成prepayId预支付Id
 packageReqHandler.SetParameter("appid", account.AppId); //公众账号ID
 packageReqHandler.SetParameter("mch_id", account.PartnertId); //商户号
 packageReqHandler.SetParameter("nonce_str", nonceStr); //随机字符串
 packageReqHandler.SetParameter("body", account.Body);
 packageReqHandler.SetParameter("out_trade_no", account.OrderSerialId); //商家订单号
 packageReqHandler.SetParameter("total_fee", account.TotalAmount); //商品金额,以分为单位(money * 100).ToString()
 packageReqHandler.SetParameter("spbill_create_ip", account.RequestIp); //用户的公网ip，不是商户服务器IP
 packageReqHandler.SetParameter("notify_url", account.NotifyUrl); //接收财付通通知的URL
 packageReqHandler.SetParameter("trade_type", "JSAPI"); //交易类型
 packageReqHandler.SetParameter("openid", account.OpenId); //用户的openId
 string sign = packageReqHandler.CreateMd5Sign("key", account.PaySignKey);
 packageReqHandler.SetParameter("sign", sign); //签名
 string prepayId = string.Empty;
 try
 {
 string data = packageReqHandler.ParseXML();
 var result = TenPayV3.Unifiedorder(data);
 MailHelp.SendMail("调用统一下单接口，下单结果：--"+result+"请求参数："+data);
 var res = XDocument.Parse(result);
 prepayId = res.Element("xml").Element("prepay_id").Value;
 AppLog.Write("调用统一下单接口获取预支付prepayId成功", AppLog.LogMessageType.Debug);
 }
 catch (Exception ex)
 {
 AppLog.Write("获取到openid和access_tokenu异常", AppLog.LogMessageType.Debug, ex);
 MailHelp.SendMail("调用统一下单接口获取预支付prepayid异常：", ex);
 return null;
 }

//生成JsAPI支付参数
 RequestHandler paySignReqHandler = new RequestHandler(null);
 paySignReqHandler.SetParameter("appId", account.AppId);
 paySignReqHandler.SetParameter("timeStamp", timeStamp);
 paySignReqHandler.SetParameter("nonceStr", nonceStr);
 paySignReqHandler.SetParameter("package", string.Format("prepay_id={0}", prepayId));
 paySignReqHandler.SetParameter("signType", "MD5");
 string paySign = paySignReqHandler.CreateMd5Sign("key", account.PaySignKey);
 WeChatJsPayRequestModel resultModel = new WeChatJsPayRequestModel
 {
 AppId = account.AppId,
 NonceStr = nonceStr,
 TimeStamp = timeStamp,
 Package = string.Format("prepay_id={0}", prepayId),
 PaySign = paySign,
 SignType = "MD5"
 };

private string CreateWeixinJs(WeChatJsPayRequestModel model)
 {
 string js = @"<script type='text/javascript'>
 callpay();
 function jsApiCall(){
 WeixinJSBridge.invoke(
 'getBrandWCPayRequest', {
 requestParam
 },
 function (res) {
 if(res.err_msg == 'get_brand_wcpay_request:ok' ){
 window.location.href = 'successUrl';
 }else{
 window.location.href = 'failUrl';
 }
 }
 ); 
 }
 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>";
 string requestParam = string.Format(@"'appId': '{0}','timeStamp': '{1}','nonceStr': '{2}','package': '{3}','signType': '{4}','paySign': '{5}'",
 model.AppId, model.TimeStamp, model.NonceStr, model.Package, model.SignType, model.PaySign);
 js = js.Replace("requestParam", requestParam)
 .Replace("successUrl", model.JumpUrl + "&result=1")
 .Replace("failUrl", model.JumpUrl + "&result=0");
 AppLog.Write("生成可执行脚本成功", AppLog.LogMessageType.Debug);
 return js;
 }

ResponseHandler resHandler = new ResponseHandler(System.Web.HttpContext.Current);
 bool isSuccess = _weChatPaySerivce.ProcessNotify(resHandler);
 if (isSuccess)
 {
 string result = @"<xml>
 <return_code><![CDATA[SUCCESS]]></return_code>
 <return_msg><![CDATA[支付成功]]></return_msg>
 </xml>";
 HttpContext.Response.Write(result);
 HttpContext.Response.End();
 }
 return new EmptyResult();