急急急急 求一高手指教淘宝api

[Jane_Five]

最近做淘宝的机票api应用开发，类型属于商家后台，可是没什么头绪，看的有点萌
初步试了试，一直说什么签名错误，不明白，淘宝好像是自己封装了，包括加密等等，不是很明白其中的意义，求教大神们不吝赐教，给一个完整的解说，谢谢各位大神了，很急的



using Top.Api;
using Top.Api.Domain;
using Top.Api.Response;
using Top.Api.Request;

public partial class Getreturnfeeproduct : System.Web.UI.Page
{
//沙箱环境调用地址:http://gw.api.tbsandbox.com/router/rest
//正式环境需要设置为:http://gw.api.taobao.com/router/rest
string url = "http://gw.api.taobao.com/router/rest";

//淘宝指定值
string appkey = "3333333";
string appsecret = "sandbox1cd6e9ssssd1596e83be761b";
protected void Page_Load(object sender, EventArgs e)
{
//判断sessionkey
if (Context.Request.QueryString["top_session"] != null)
{
Context.Session["sessionkey"] = Context.Request.QueryString["top_session"];
}
else if (Context.Session["sessionkey"] == null)
{
Context.Response.Redirect("http://container.api.taobao.com/container?appkey=3333333&encode=utf-8");
}
}
protected void Button1_Click(object sender, EventArgs e)
{
ITopClient myclient = new DefaultTopClient(url, appkey, appsecret);//实例化ITopClient类
//taobao.jipiao.returnfeeproduct.get 查询让利产品
JipiaoReturnfeeproductGetRequest req = new JipiaoReturnfeeproductGetRequest();
req.OutProductId = "123456";

JipiaoReturnfeeproductGetResponse response = myclient.Execute(req, Session["sessionkey"].ToString());
txt_out_product_id.Text = response.Body;
string s = response.ErrCode;
}
}