.net服务端接入支付宝接口

public class AlipayConfig
    {
        //APPID
        public static string appId = "2016101500694440";
        //支付宝网关
        public static string gateway = "https://openapi.alipaydev.com/gateway.do";
        //用户私钥
        public static string privateKey = "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";
        //支付宝公钥
        public static string alipayPublicKey = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAlUaqoPnb+UVjC/lEUcRytpMQtbVKcTnsT4derbrju/wbvwnL+CjJ8jNgIA8jysAwk2NOzZUY5JU3P24CnW16KiPHiqlWUB4YE1ZJEMmAu5qedu37XjYBmKUFoTtoFq2YtVvFCTQFmRYcFwRARbXFWyUMF30b+mOiD6bldsFtf7VzU6bawOs7YsgCMpUBcA+iIxNIZ8dK8s6PYzn54pKsHmID6Og+VOwNkvjnYG1xOAXqK5Fz6JPaJQRR/XvkHcqVWwBwOFCWx9XXOCNKxgYKY3J/RENSy3JV9IbKtxnWyrb54G32gdT4h+VOaDggqTaH8Pxk7oRCegqBpZdcr+SCqQIDAQAB";
        //支付成功的回调地址
        public static string returnURL = "Student/Index";
        // 签名方式  
        public static string sign_type = "RSA2";
        // 编码格式  
        public static string charset = "UTF-8";

        private static string generateOrderNumber()
        {
            return DateTime.Now.ToString("yyyyMMddHHmmssfff");
        }

        /*
         * 创建支付model
         * price：商品价格
         * title：商品标题
         * description：商品描述
         * **/
        public static AlipayTradePagePayModel creatModel(string price, string title, string description)
        {
            AlipayTradePagePayModel model = new AlipayTradePagePayModel();
            model.Body = description;
            model.Subject = title;
            //付款金额
            model.TotalAmount = price;
            //商户网站中唯一订单号
            model.OutTradeNo = generateOrderNumber();
            model.ProductCode = "FAST_INSTANT_TRADE_PAY";
            return model;
        }

    }

public string Index()
        {
            DefaultAopClient client = new DefaultAopClient(AlipayConfig.gateway, AlipayConfig.appId, AlipayConfig.privateKey, "json", "1.0", AlipayConfig.sign_type, AlipayConfig.alipayPublicKey, AlipayConfig.charset, false);
            //金额格式必须是小数点后两位数或是正整数且不是金额格式（即$123.00），以及非常重要的一个原则，传递的参数要么不传递这个参数（即传递的众多参数中，这个参数完全不存在
            AlipayTradePagePayModel model = AlipayConfig.creatModel("9.90","测试商品","测试商品支付");
            AlipayTradePagePayRequest request = new AlipayTradePagePayRequest();
            //支付成功的回调地址
            request.SetReturnUrl("xxxxxxxxxx");
            // 设置异步通知接收地址，需要公网能够访问
            request.SetNotifyUrl("xxxxxxxxxx");
            // 将业务model载入到request
            request.SetBizModel(model);

            AlipayTradePagePayResponse response = null;
            try
            {
                response = client.pageExecute(request);
                return response.Body;
            }
            catch (Exception exp)
            {
                throw exp;
            }

        }

public void notify()
        {
            Dictionary<string, string> sArray = GetRequestPost();
            if(sArray.Count > 0){
                

                //调用SDK验签方法
                bool signVerified = AlipaySignature.RSACheckV1(sArray, AlipayConfig.alipayPublicKey, AlipayConfig.charset);
                //此判断结果中书写业务逻辑代码
                if (signVerified)   //验证支付发过来的消息，签名是否正确
                {
                    //商户订单号
                    string out_trade_no = Request.Form["out_trade_no"];

                    //支付宝交易号
                    string trade_no = Request.Form["trade_no"];

                    //交易状态
                    string trade_status = Request.Form["trade_status"];


                    if (Request.Form["trade_status"] == "TRADE_FINISHED")
                    {
                        //判断该笔订单是否在商户网站中已经做过处理
                        //如果没有做过处理，根据订单号（out_trade_no）在商户网站的订单系统中查到该笔订单的详细，并执行商户的业务程序
                        //如果有做过处理，不执行商户的业务程序

                        //注意：
                        //退款日期超过可退款期限后（如三个月可退款），支付宝系统发送该交易状态通知
                    }
                    else if (Request.Form["trade_status"] == "TRADE_SUCCESS")
                    {
                        //判断该笔订单是否在商户网站中已经做过处理
                        //如果没有做过处理，根据订单号（out_trade_no）在商户网站的订单系统中查到该笔订单的详细，并执行商户的业务程序
                        //如果有做过处理，不执行商户的业务程序

                        //注意：
                        //付款完成后，支付宝系统发送该交易状态通知
                        
                        //请在这里加上商户的业务逻辑程序代码

                    }
                    else
                    {
                    }
                    Response.Write("success");     //返回给支付宝消息，成功,这里不要动！！！
                }
                else
                {
                    Response.Write("fail");
                }
            }

        }

        public Dictionary<string, string> GetRequestPost()
        {
            int i = 0;
            Dictionary<string, string> sArray = new Dictionary<string, string>();
            NameValueCollection coll;
            coll = Request.Form;
            String[] requestItem = coll.AllKeys;
            for (i = 0; i < requestItem.Length; i++)
            {
                sArray.Add(requestItem[i], Request.Form[requestItem[i]]);
            }
            return sArray;

        }