C#.net支付宝接口

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Text;

public partial class pay : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
Encoding gb2312 = Encoding.GetEncoding("gb2312");
Response.ContentEncoding = gb2312;
Request.ContentEncoding = gb2312;
}

protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
{
if (Request.Cookies[FormsAuthentication.FormsCookieName] != null)
{
Vlike_DB_read a = new Vlike_DB_read();
string zfb_ddh = a.get_zfb_id(Membership.GetUser().UserName, Convert.ToInt32(DropDownList1.SelectedValue));
Response.Redirect(img("0001", "包月", "影视包月  10元/月", zfb_ddh, "10.00", Membership.GetUser().UserName.ToUpper(), DropDownList1.SelectedValue));
}
else
{
Response.Write("");
}
}

private string img(string strcmd, string strSub, string strSubinfo, string strid, string strMoney, string strUser, string strNum)
{
string strsellerEmail = "341081@qq.com";          //卖家支付宝帐号
        string strAc = "";        　　　　//卖家支付宝安全校验码
string INTERFACE_URL = "https://www.alipay.com/payto:";
        string strCmd = strcmd;           //命令字
        string strSubject = strSub;       //商品名
        string strBody = strSubinfo;      //商品描述
        string strOrder_no = strid;       //商户订单号
        string strPrice = strMoney;       //商品单价 0.01～50000.00
        string rurl = "http://";          //商品展示网址
        string strType = "2";             //type支付类型    1：商品购买2：服务购买3：网络拍卖4：捐赠
        string strNumber = strNum;        //购买数量
        string strTransport = "3";        //发货方式        1：平邮2：快递3：虚拟物品
        string strOrdinary_fee = "";      //平邮运费
        string strExpress_fee = "";       //快递运费
        string strReadOnly = "true";      //交易信息是否只读
        string strBuyer_msg = "";         //买家给卖家的留言

string strBuyer = "";             //买家EMAIL
        string strBuyer_name = strUser;   //买家姓名
        string strBuyer_address = "";     //买家地址
        string strBuyer_zipcode = "";     //买家邮编
        string strBuyer_tel = "";         //买家电话号码
        string strBuyer_mobile = "";      //买家手机号码
        string strPartner = "";           //合作伙伴ID    保留字段

return CreatUrl(strsellerEmail, strAc, INTERFACE_URL, strCmd, strSubject, strBody,
strOrder_no, strPrice, rurl, strType, strNumber, strTransport,
strOrdinary_fee, strExpress_fee, strReadOnly, strBuyer_msg, strBuyer,
strBuyer_name, strBuyer_address, strBuyer_zipcode, strBuyer_tel,
strBuyer_mobile, strPartner);
}
private string CreatUrl(
string strsellerEmail,
string strAc,
string INTERFACE_URL,
string strCmd,
string strSubject,
string strBody,
string strOrder_no,
string strPrice,
string rurl,
string strType,
string strNumber,
string strTransport,
string strOrdinary_fee,
string strExpress_fee,
string strReadOnly,
string strBuyer_msg,
string strBuyer,
string strBuyer_name,
string strBuyer_address,
string strBuyer_zipcode,
string strBuyer_tel,
string strBuyer_mobile,
string strPartner)
{   //以下参数值不能留空

string str2CreateAc = "";
str2CreateAc += "cmd" + strCmd + "subject" + strSubject;
str2CreateAc += "body" + strBody;
str2CreateAc += "order_no" + strOrder_no;
str2CreateAc += "price" + strPrice;
str2CreateAc += "url" + rurl;
str2CreateAc += "type" + strType;
str2CreateAc += "number" + strNumber;
str2CreateAc += "transport" + strTransport;
str2CreateAc += "ordinary_fee" + strOrdinary_fee;
str2CreateAc += "express_fee" + strExpress_fee;
str2CreateAc += "readonly" + strReadOnly;
str2CreateAc += "buyer_msg" + strBuyer_msg;
str2CreateAc += "seller" + strsellerEmail;
str2CreateAc += "buyer" + strBuyer;
str2CreateAc += "buyer_name" + strBuyer_name;
str2CreateAc += "buyer_address" + strBuyer_address;
str2CreateAc += "buyer_zipcode" + strBuyer_zipcode;
str2CreateAc += "buyer_tel" + strBuyer_tel;
str2CreateAc += "buyer_mobile" + strBuyer_mobile;
str2CreateAc += "partner" + strPartner;
str2CreateAc += strAc;

string acCode = GetMD5(str2CreateAc);

string parameter = "";

parameter += INTERFACE_URL + strsellerEmail + "?cmd=" + strCmd;
parameter += "&subject=" + Server.UrlEncode(strSubject);
parameter += "&body=" + Server.UrlEncode(strBody);
parameter += "&order_no=" + strOrder_no;
parameter += "&url=" + rurl;
parameter += "&price=" + strPrice;
parameter += "&type=" + strType;
parameter += "&number=" + strNumber;
parameter += "&transport=" + strTransport;
parameter += "&ordinary_fee=" + strOrdinary_fee;
parameter += "&express_fee=" + strExpress_fee;
parameter += "&readonly=" + strReadOnly;
parameter += "&buyer_msg=" + strBuyer_msg;
parameter += "&buyer=" + strBuyer;
parameter += "&buyer_name=" + Server.UrlEncode(strBuyer_name);
parameter += "&buyer_address=" + strBuyer_address;
parameter += "&buyer_zipcode=" + strBuyer_zipcode;
parameter += "&buyer_tel=" + strBuyer_tel;
parameter += "&buyer_mobile=" + strBuyer_mobile;
parameter += "&partner=" + strPartner;
parameter += "&ac=" + acCode;

return parameter;
}

private static string GetMD5(string s)
{
System.Security.Cryptography.MD5 md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
byte[] t = md5.ComputeHash(System.Text.Encoding.GetEncoding("gb2312").GetBytes(s));
System.Text.StringBuilder sb = new System.Text.StringBuilder(32);
for (int i = 0; i < t.Length; i++)
{
sb.Append(t[i].ToString("x").PadLeft(2, '0'));
}
return sb.ToString();
}
}