请参阅WP 7.1添加cookie

我试图使用RestSharp向请求添加cookie，但在fiddler2中，我在请求中看不到cookie，服务调用失败。在RestRequest中添加cookie有什么诀窍吗？

 RestRequest rq = new RestRequest(LTV.NowNext(), Method.GET);
        rc.AddDefaultParameter(LTV.cookie.Key, LTV.cookie.Value, ParameterType.Cookie);
        rc.ExecuteAsync<LTV.nowNext>(rq, (response2) =>
        {
            if (response2.Data == null)
                return;
            foreach (LTV.channel channel in response2.Data.channels)
                this.Items.Add(new ItemViewModel() { LineOne = channel.name, LineTwo = channel.showing[0].content[0].parent.title, LineThree = channel.showing[1].content[0].parent.title });
        });

谢谢，Al