silverlight设置浏览器Cookies

private void SetCookie(string key, string value)
         {    
             // 7天过期    
             DateTime expireDate = DateTime.Now + TimeSpan.FromDays(7);
             string newCookie = key + "=" + value + ";expires=" + expireDate.ToString("R");
             HtmlPage.Document.SetProperty("cookie", newCookie);
         } 
 

private string GetCookie(string key)
         {
             string[] cookies = HtmlPage.Document.Cookies.Split(';');
             foreach (string cookie in cookies)
             {
                 string[] keyValue = cookie.Split('=');
                 if (keyValue.Length == 2)
                 {
                     if (keyValue[0].ToString() == key)
                     {
                         return keyValue[1];
                     }
                 }
             }
             return null;
         }