通过http Post XML文件的接口 （System.Web.IHttpHandler）

//httppost.cs  文件内容（放入App_code里面）
public class httppost : System.Web.IHttpHandler
{
    private string mobile;//手机号
    private string amount;//交易金额
    private string user;//用户
    private string orderNo;//订单号
    private string payType;// '0' - 话费支付 '1' - 移动电子账户支付
    private string trxType;//交易类型
    string nowTime;

    public http_SpPay()
    {
    }
    public void ProcessRequest(HttpContext context)
    {
        HttpRequest Request = context.Request;
        Stream content = Request.InputStream;
        StreamReader sr = new StreamReader(content);
        string resStr = sr.ReadToEnd();
        sr.Close();
        content.Close();
        string clientIP = GetUserIP(Request);
       
        if (ReadReceiveXml(resStr))//读取接受报文
        {
            SpPay pay = new SpPay();
            if (PaySend(pay,clientIP, mobile, amount, orderNo, trxType, payType))
            {
                ReturnTo("<?xml version='1.0' encoding='gb2312'?><cmts>" +
                    "<UserMobile>" + mobile + "</UserMobile>" +
                    "<Amount>" + amount + "</Amount>" +
                    "<OrderNo>" + orderNo + "</OrderNo>" +
                    "<ResultCode>0</ResultCode>" +
                    "<ResultCodeInfo>扣费成功</ResultCodeInfo>" +
                    "</cmts>", context);
            }
            else
            {
                ReturnTo("<?xml version='1.0' encoding='gb2312'?><cmts>" +
                    "<UserMobile>" + mobile + "</UserMobile>" +
                    "<Amount>" + amount + "</Amount>" +
                    "<OrderNo>" + orderNo + "</OrderNo>" +
                    "<ResultCode>" + pay.ResultCode + "</ResultCode>" +
                    "<ResultCodeInfo>" + pay.ErroString + "</ResultCodeInfo>" +
                    "</cmts>", context);
            }
            pay = null;
        }
        else
        {
            ReturnTo("<?xml version='1.0' encoding='gb2312'?><cmts>" +
                "<ResultCode>2</ResultCode>" +
                "<ResultCodeInfo>报文错误</ResultCodeInfo>" +
                "</cmts>", context);
        }
       
    }

    public bool IsReusable
    {
        get { return false; }
    }

    //取客户端IP
    public string GetUserIP(HttpRequest Request)
    {
        string userIP;
        if (Request.ServerVariables["HTTP_VIA"] == null)
        {
            userIP = Request.UserHostAddress;
        }
        else
        {
            userIP = Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
        }
        return userIP;
    }

    #region 即时返回
    private void ReturnTo(string content, HttpContext context)
    {
        HttpResponse Response = context.Response;
        Response.Write(content);
    }
    #endregion

    #region 读取post内容  读取xml
    private bool ReadReceiveXml(string receiveXml)
    {
        try
        {
            XmlDocument doc = new XmlDocument();
            doc.Load(new StringReader(receiveXml));  // 装入指定的XML文档
            XmlNodeList elemList = doc.GetElementsByTagName("xml");
            XmlNodeList subelemList;

            XmlElement elem = (XmlElement)elemList[0];
            subelemList = elem.GetElementsByTagName("UserMobile");
            mobile = subelemList[0].InnerText;
            subelemList = elem.GetElementsByTagName("Amount");
            amount = subelemList[0].InnerText;
            subelemList = elem.GetElementsByTagName("user");
            user = subelemList[0].InnerText;

            subelemList = elem.GetElementsByTagName("OrderNo");
            orderNo = subelemList[0].InnerText;
            subelemList = elem.GetElementsByTagName("PayType");
            payType = subelemList[0].InnerText;
            subelemList = elem.GetElementsByTagName("TrxType");
            trxType = subelemList[0].InnerText;
        }
        catch
        {
            return false;
        }
        return true;
    }
    #endregion

    #region 支付方法
    private bool PaySend(SpPay pay,string clientIP, string userMobile, string amount, string orderNo, string trxType, string payType)
    {
        nowTime = Convert.ToString(DateTime.Now.Year) + String.Format("{0:00}", Int32.Parse(Convert.ToString(DateTime.Now.Month))) + String.Format("{0:00}", Int32.Parse(Convert.ToString(DateTime.Now.Day)))
        + String.Format("{0:00}", Int32.Parse(Convert.ToString(DateTime.Now.Hour))) + String.Format("{0:00}", Int32.Parse(Convert.ToString(DateTime.Now.Minute))) + String.Format("{0:00}", Int32.Parse(Convert.ToString(DateTime.Now.Second)));;//'SP交易时间：年月日时分 秒：20030420233020
        return (bool));
    }
    #endregion
}

//webconfig配置
</system.web>
<httpHandlers>
 <add verb="*" path="httppost.cmts" type="httppost"/>
</httpHandlers>
</system.web>

//IIS配置
网站属性--〉主目录 --〉配置 -->添加 --〉浏览这个文件（aspnet_isapi.dll）--〉扩展名（cmts） --〉确定