.net c#微信支付

using System;
using System.Text;
using System.Reflection;
using System.Security.Cryptography;
using System.Net;
public partial class wxpay : System.Web.UI.Page
{
    DAL dal = new DAL();
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            string type = Request.Form["type"];
            string userId = Request.Form["userId"];
                //一.系统本身自有的业务处理
                //1.必要信息的初始化
                  //用户主键
                string orderId = DateTime.Now.ToFileTimeUtc().ToString(); //生成订单号
                decimal totalFee = 980;//设置默认商品费用为【1分】
                string nonceStr = DateTime.Now.ToFileTimeUtc().ToString();   //获取 随机字符串
                dal.caozuo("insert into orders values('" + orderId + "','" + userId + "','" + totalFee + "','" + DateTime.Now + "'," + 0 + ")");
                // dal.caozuo("insert into orders values('1','1','1','1',0)");

                //二.微信系统下单
                //1.创建支付应答对象并初始化
                PaySign sign = GetPaySign(orderId, totalFee, nonceStr, Request.UserHostAddress);
                string signs = ModelToUriParam(sign) + "&key=";
                string md5Signs = MD5(signs).ToUpper();//MD5签名
                string body = GenerateBodyXml(sign, md5Signs);
                byte[] postData = Encoding.UTF8.GetBytes(body);//编码，尤其是汉字，事先要看下抓取网页的编码方式  
                string url = "";//地址
                WebClient webClient = new WebClient();
                webClient.Headers.Add("Content-Type", "application/json");//采取POST方式必须加的header，如果改为GET方式的话就去掉这句话即可
                byte[] responseData = webClient.UploadData(url, "POST", postData);//得到返回字符流
                string srcString = Encoding.UTF8.GetString(responseData);//解码

                Response.Write(srcString);
        }
    }

    private static string GenerateBodyXml(object obj, string md5Signs)
    {
        PropertyInfo[] propertis = obj.GetType().GetProperties();
        StringBuilder sb = new StringBuilder();
        sb.Append("");
        foreach (var p in propertis)
        {
            var v = p.GetValue(obj, null);
            if (v == null)
                continue;
            sb.AppendFormat("<{0}>{1}", p.Name, v.ToString());
        }
        sb.AppendFormat("{0}", md5Signs);
        sb.Append("");

        return sb.ToString();
    }

    protected static string MD5(string inputText)
    {
        System.Security.Cryptography.MD5 md5 = new MD5CryptoServiceProvider();
        byte[] fromData = System.Text.Encoding.UTF8.GetBytes(inputText);
        byte[] targetData = md5.ComputeHash(fromData);
        string byte2String = null;

        for (int i = 0; i < targetData.Length; i++)
        {
            byte2String += targetData[i].ToString("x2");
        }

        return byte2String;
    }

    protected static string ModelToUriParam(object obj)
    {
        PropertyInfo[] propertis = obj.GetType().GetProperties();
        StringBuilder sb = new StringBuilder();
        foreach (var p in propertis)
        {
            var v = p.GetValue(obj, null);
            if (v == null)
                continue;

            sb.Append(p.Name);
            sb.Append("=");
            sb.Append(v.ToString());
            //sb.Append(HttpUtility.UrlEncode(v.ToString()));
            sb.Append("&");
        }
        sb.Remove(sb.Length - 1, 1);

        return sb.ToString();
    }

    private static PaySign GetPaySign(string orderid,decimal merFee, string nonceStr,string clientId)
        {
            PaySign paySign = new PaySign
            {
                appid = "",
                body = "111",
                mch_id = "",
                nonce_str = nonceStr,
                notify_url = "",
                out_trade_no = orderid,
                spbill_create_ip = clientId,
                total_fee = (Math.Round(merFee * 100, 0)).ToString(),//转化为单位:分，且只能为整型
                trade_type = "MWEB"
            };
            return paySign;
        }

  

    /// 

    /// 签名类A（请注意，此类的属性字段顺序不可调整）
    /// 微信预支付前面规则，是按参数ASCII码依次排列的，以下属性已人为排列
    /// 
    public class PaySign
    {
        public string appid { get; set; }
        /// 

        /// 附加数据(描述)
        /// 
        public string attach { get; set; }
        /// 

        /// 商品描述
        /// 
        public string body { get; set; }
        /// 

        /// 商户号
        /// 
        public string mch_id { get; set; }
        /// 

        /// 小于32位的随机数
        /// 
        public string nonce_str { get; set; }
        /// 

        /// 通知地址
        /// 
        public string notify_url { get; set; }
        /// 

        /// 微信用户openid
        /// 
        public string openid { get; set; }
        /// 

        /// 商户订单号
        /// 
        public string out_trade_no { get; set; }
        /// 

        /// 客户端ip
        /// 
        public string spbill_create_ip { get; set; }
        /// 

        /// 订单金额
        /// 
        public object total_fee { get; set; }
        /// 

        /// 支付类型
        /// 
        public string trade_type { get; set; }
    }

    /// 

    /// 返回前端的签名类B（请注意，此类的属性字段顺序不可调整）
    /// 
    public class ResSign
    {
        public string appId { get; set; }
        /// 

        /// 小于32位的随机数
        /// 
        public string nonceStr { get; set; }
        /// 

        /// package
        /// 
        public string package { get; set; }
        /// 

        /// signType
        /// 
        public string signType { get; set; }
        /// 

        /// timeStamp
        /// 
        public string timeStamp { get; set; }
        /// 

        /// key
        /// 
        public string key { get; set; }
    }
}