.net mvc 微信支付

 一、微信第三方登录
 通过微信打开链接:http://www.hzm.com/Entry/Login
 微信OAuth2.0授权登录目前支持authorization_code模式，适用于拥有server端的应用授权。该模式整体流程为：
 　　. 第三方发起微信授权登录请求，微信用户允许授权第三方应用后，微信会拉起应用或重定向到第三方网站，并且带上授权临时票据code参数；

 　　. 通过code参数加上AppID和AppSecret等，通过API换取access_token；

 　　. 通过access_token进行接口调用，获取用户基本数据资源或帮助用户实现基本操作。
 .控制器中代码
 public ActionResult Login()
 {
     //若已经登录，直接跳到首页
     if (HttpContext.User.Identity.IsAuthenticated)
     {
         return RedirectToAction("Index", "Entry");
     }
     //微信登录
     //1.获取code
     if (string.IsNullOrEmpty(Request.QueryString["code"]))
     {
         //从定向到微信，微信再重定向到当前函数(进入第1步获取code)
         return RedirectToWeixin();
     }
     //2.获取openID
     //通过code获取openID
     string openID = "";
     try
     {
          openID = GetOpenID(Request.QueryString["code"]);
     }
     catch(Exception e)
     {
         Log.Debug("GetOpenID Exception", e.StackTrace);
         return Redirect("/Entry/Login");
     }
     //3.查找或存储用户信息
     User user = new User();
     user = db.Users.SingleOrDefault(p => p.OpenID == openID);
     if (user == null)
     {
         //添加用户
         user = new User();
         user.OpenID = openID;
         db.Users.Add(user);
         db.SaveChanges();
     }
     //登录成功
     FormsAuthentication.SetAuthCookie(user.ID.ToString(), false);//记录登录凭证
     return RedirectToAction("Index", "Entry");
 }
 1.1.获取code
  private ActionResult RedirectToWeixin()
 {
     JsApiPay jsApiPay = new JsApiPay(this);
     var redirect_url = jsApiPay.GetRedirectToWeixinUrlForCode();//将回调stata参数值设为awardUserID
     return Redirect(redirect_url);//调回:/Entry/Login
 }
 1.2.通过code获取openID和access_token
 private string GetOpenID(string code)
 {
     JsApiPay jsApiPay = new JsApiPay(this);
     //如果code有值
     if (!string.IsNullOrEmpty(code))
     {
         Log.Debug(" GetOpenID code", code);
         //去获取OpenID
         jsApiPay.GetOpenidAndAccessTokenFromCode(code);
     }
     Log.Debug("GetOpenidAndAccessTokenFromCode openid", jsApiPay.openid.ToString());
     return jsApiPay.openid.ToString();
 }
 二、微信支付
 2.1.生成业务订单和微信交易号Out_trade_no
 public ActionResult CreateOrder(int entryID, PayMode payMode)
 {
     //一个报名只应对应一个订单
     //判断订单是否已经存在,则直接进入详情页
     if (db.Orders.Any(p => p.EntryID == entryID))
     {
         return Redirect("/Entry/Detail?out_trade_no=" + db.Orders.SingleOrDefault(p => p.EntryID == entryID).Out_trade_no);
     }
     Entry entry = db.Entrys.Include("Event").SingleOrDefault(p => p.ID == entryID);
     Order order = new Order();
     order.EntryID = entry.ID;
     order.Amount = GetDiscount(entry.Event);
     order.PayMode = payMode;
     order.State = OrderSatet.Unpaid;
     order.SubmitTime = DateTime.Now;
     order.Body = entry.Event.Theme;
     order.Out_trade_no = WxPayApi.GenerateOutTradeNo();
     db.Orders.Add(order);
     db.SaveChanges();
     if (payMode == PayMode.Remittance)
     {
         return RedirectToAction("Detail", new { out_trade_no = order.Out_trade_no });
     }
     return RedirectToAction("Pay", new { orderID = order.ID });
 }
 2.2.微信支付
 public ActionResult Pay(int orderID)
 {
     //获取订单
     Order order = db.Orders.SingleOrDefault(p => p.ID == orderID);

     //修改支付方式
     order.PayMode = PayMode.Weixin;
     db.SaveChanges();

     //微信openID
     Entry entry = db.Entrys.Include("Event").SingleOrDefault(p => p.ID == order.EntryID);
     User user = db.Users.SingleOrDefault(p => p.ID == entry.UserID);
     Log.Debug("openID", user.OpenID);
     Log.Debug("entry.UserID", entry.UserID.ToString());
     Log.Debug("HttpContext.User.Identity.Name", HttpContext.User.Identity.Name);
     //当前订单的商户系统的订单号
     ViewData["out_trade_no"] = order.Out_trade_no;
     //支付费用
     decimal totalFee = GetDiscount(entry.Event);
     Log.Debug("totalFee", "100.00");
     JsApiPay jsApiPay = new JsApiPay(this);
     try
     {
         //若传递了相关参数，则调统一下单接口，获得后续相关接口的入口参数
         jsApiPay.openid = user.OpenID;

         jsApiPay.total_fee =  Convert.ToInt32(totalFee * );//支持两位小数，如0.01
         Log.Debug(this.GetType().ToString(), "参数赋值成功1");
         //JSAPI支付预处理
         Log.Debug(this.GetType().ToString(), "参数赋值成功2");
         WxPayData unifiedOrderResult = jsApiPay.GetUnifiedOrderResult(entry.Name + "的" + entry.Event.Theme, "报名", order.Out_trade_no);

         Log.Debug(this.GetType().ToString(), "预支付订单生成成功");
         //获取H5调起JS API参数
         var wxJsApiParam = jsApiPay.GetJsApiParameters();
         ViewData["wxJsApiParam"] = wxJsApiParam;

         Log.Debug(this.GetType().ToString(), "wxJsApiParam参数获取成功");
         //预支付订单号
         var prepay_id = jsApiPay.unifiedOrderResult.GetValue("prepay_id").ToString();
         ViewData["prepay_id"] = prepay_id;
         Log.Debug(this.GetType().ToString(), "prepay_id参数获取成功");
         /*###################################*/
         Log.Debug(this.GetType().ToString(), "wxJsApiParam : " + wxJsApiParam);
     }
     catch (Exception ex)
     {
         Response.Write("<span style='color:#FF0000;font-size:20px'>" + "下单失败，请返回重试" + "</span>");
         Log.Debug("Award-ConfirmPayPage", ex.Message + ex.StackTrace);
         Log.Debug("Award-ConfirmPayPage", "预支付订单生成或保存异常");
     }

     return View();

 }
 2.3.页面中调起微信支付接口(Pay.html)
 @{
     Layout = null;
 }
 <!DOCTYPE html>
 <html>
 <head>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
     <title>支付页面</title>
     <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no">
     <script type="text/javascript">
         var wxJsApiParam=@Html.Raw(ViewData["wxJsApiParam"].ToString());
     //调用微信JS api 支付

     function jsApiCall() {
         WeixinJSBridge.invoke(
                 'getBrandWCPayRequest',
                 wxJsApiParam,
                 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"){
                         location.href ="/Entry/Detail?out_trade_no=@ViewData["out_trade_no"]";
                     }else
                     {
                         location.href ="/Entry/Detail?out_trade_no=@ViewData["out_trade_no"]";
                     }

                         //alert(res.err_msg);
                      }
                 );
         }

         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();
             }
         }
         callpay();
     </script>
 </head>
 <body>
 </body>
 </html>
 2.4.支付成功后微信发送支付成功异步通知(post方式，通知地址在Config.cs中配置的NOTIFY_URL，在这里添加订单处理业务逻辑)
 public ActionResult Notify()
 {
     ResultNotify notify = new ResultNotify(this);
     WxPayData data = notify.GetNotifyData();
     Log.Debug("return_code", data.GetValue("return_code").ToString());
     Log.Debug("return_msg", data.GetValue("return_code").ToString());
     if (data.GetValue("return_code").ToString() == "SUCCESS")
     {
         Log.Debug("out_trade_no", data.GetValue("out_trade_no").ToString());
         var out_trade_no = data.GetValue("out_trade_no").ToString();

         Order order = db.Orders.SingleOrDefault(p => p.Out_trade_no == out_trade_no);
         Log.Debug("orderID", order.ID.ToString());

         order.State = OrderSatet.Paid;
         var time_end = data.GetValue("time_end").ToString();
         order.PayTime = DateTime.ParseExact(time_end, "yyyyMMddHHmmss", CultureInfo.CurrentCulture);
         order.TransactionID = data.GetValue("transaction_id").ToString();
         order.OpenID = data.GetValue("openid").ToString();
         db.SaveChanges();

     }
     notify.ProcessNotify();

     return View();
 }
 2.5.支付成功后跳转到(Pay.html页面设置的地址)
 如:location.href ="/Entry/Detail?out_trade_no=@ViewData["out_trade_no"]";
微信支付官方文档地址：
1.App微信支付：https://pay.weixin.qq.com/wiki/doc/api/app/app.php?chapter=8_3