支付寶的接口調用很不方便，剛做好一個封裝，實現了虛擬交易和實物交易。
解決方案中有三個項目以及NDoc生成的文檔，簡單的序列圖：CommonAlipay，封裝的支付寶接口。
 TestAli,asp.net的測試項目
TestCommonAliPay，Nunit的測試項目。
調用方法：
1、引入CommonAliPay.dll
2、實現支付寶服務接口的方法調用方式：
 AliPay ap = new AliPay();
        string key = "";//填寫自己的key
        string partner = "";//填寫自己的Partner
        StandardGoods bp = new StandardGoods("trade_create_by_buyer", partner, key, "md5", "卡2", Guid.NewGuid().ToString(), 2.551m, 1, "hao_ding2000@yahoo.com.cn", "hao_ding2000@yahoo.com.cn"
            , "EMS", 25.00m, "BUYER_PAY","1");
           bp.Notify_Url = "        ap.CreateStandardTrade("https://www.alipay.com/coOperate/gateway.do", bp, this);上面是通用的調用方式。
下面是只支持虛擬貨物的方式：
 string key = "";//填寫自己的key
        string partner = "";//填寫自己的Partner
        AliPay ap = new AliPay();
        DigitalGoods bp = new DigitalGoods("create_digital_goods_trade_p", partner, key, "MD5", "卡2", Guid.NewGuid().ToString(), 2.551m, 1, "hao_ding2000@yahoo.com.cn", "hao_ding2000@yahoo.com.cn");
        bp.Notify_Url = "        ap.CreateDigitalTrade("PRotected void Page_Load(object sender, EventArgs e)
    {
      
        string key = "";//填寫自己的key
        string partner = "";//填寫自己的Partner
         AliPay ap = new AliPay();
         string notifyid = Request.Form["notify_id"];
         Verify v = new Verify("notify_verify", partner, notifyid);
        ap.WaitSellerSendGoods+=new AliPay.ProcessNotifyEventHandler(ap_WaitSellerSendGoods);
        ap.WaitBuyerPay += new AliPay.ProcessNotifyEventHandler(ap_WaitBuyerPay);
        ap.ProcessNotify(this, "    }

    void ap_WaitBuyerPay(object sender, NotifyEventArgs e)
    {
        // //加入自己的處理邏輯
        Log4net.log.Error("wait buyer pay fire");
    }

  
    private void ap_WaitSellerSendGoods(object sender, NotifyEventArgs e)
    {
        //加入自己的處理邏輯
        Log4net.log.Error("WaitSellerSendGoods fire");
    }支付寶的交易狀態都被定義成了類似名稱的事件。
部分源代碼解析：
1、解析Forms集合到NotifyEventArgs類，因為后面此類的數據要用來做MD5Sign，所以所有值類型，不能存在初始值，如：int的0等。因此用Nullable范型。
   private NotifyEventArgs ParseNotify(NameValueCollection nv, object obj)
        {
            PropertyInfo[] propertyInfos = obj.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance);

            foreach (PropertyInfo pi in propertyInfos)
            {
                string v = nv.Get(pi.Name.ToLower());
                if (v != null)
                {
                    if (pi.PropertyType == typeof(string))
                    {

                        pi.SetValue(obj, v, null);

                    }
                    else if (pi.PropertyType == typeof(int?))
                    {
                        pi.SetValue(obj, int.Parse(v), null);
                    }
                    else if (pi.PropertyType == typeof(decimal?))
                    {

                        pi.SetValue(obj, decimal.Parse(v), null);
                    }
                    else if (pi.PropertyType == typeof(DateTime?))
                    {

                        pi.SetValue(obj, DateTime.Parse(v), null);
                    }
                    else if (pi.PropertyType == typeof(bool))
                    {

                        pi.SetValue(obj, bool.Parse(v), null);
                    }
                    else
                    {
                        //轉型失敗會拋出異常
                        pi.SetValue(obj, v, null);
                    }
                }

            }
            return (NotifyEventArgs)obj;

        }
2、從類型中獲取排序后的參數
 /**//// <summary>
        /// 獲取排序后的參數
        /// </summary>
        /// <param name="obj"></param>
        /// <returns></returns>
        private SortedList<string,string> GetParam(object obj)
        {
           
            PropertyInfo[] propertyInfos = obj.GetType().GetProperties(BindingFlags.Public|BindingFlags.Instance);         
            SortedList<string, string> sortedList = new SortedList<string, string>(StringComparer.CurrentCultureIgnoreCase);
            foreach (PropertyInfo pi in propertyInfos)
            {

                if (pi.GetValue(obj, null) != null)
                {
                    if (pi.Name == "Sign" || pi.Name == "Sign_Type")
                    {
                        continue;
                    }
                    sortedList.Add(pi.Name.ToLower(), pi.GetValue(obj, null).ToString());
                 
                }
            }
            return sortedList;
                   
        }3、從SortedList中產生參數
 private string GetUrlParam(SortedList<string, string> sortedList,bool isEncode)
        {
            StringBuilder param = new StringBuilder();
            StringBuilder encodeParam = new StringBuilder();
            if (isEncode == false)
            {

                foreach (KeyValuePair<string, string> kvp in sortedList)
                {
                    string t = string.Format("{0}={1}", kvp.Key, kvp.Value);
                    param.Append(t + "&");
                }
                return param.ToString().TrimEnd('&');
            }
            else
            {
                foreach (KeyValuePair<string, string> kvp in sortedList)
                {
                     string et = string.Format("{0}={1}", HttpUtility.UrlEncode(kvp.Key), HttpUtility.UrlEncode(kvp.Value));
                     encodeParam.Append(et + "&");
                }
                return encodeParam.ToString().TrimEnd('&');
            }
 
        }
下載地址：http://www.49028c.com/Files/bluewater/CommonAliPay.rar