设置，获取和删除Cookies

#region 保存用户名的Cookie
/// <summary>
/// 设置Cookie
/// </summary>
/// <param name="cookieName"></param>
/// <param name="key"></param>
/// <param name="value"></param>
/// <param name="expires"></param>
/// <returns></returns>
public HttpCookie SetCookie(string cookieName, string key, string value, DateTime? expires)
{
HttpResponse response = System.Web.HttpContext.Current.Response;
if (response != null)
{
HttpCookie cookie = response.Cookies[cookieName];
if (cookie != null)
{
if (!string.IsNullOrEmpty(key) && cookie.HasKeys)
cookie.Values.Set(key, value);
else
if (!string.IsNullOrEmpty(value))
cookie.Value = value;
if (expires != null)
cookie.Expires = expires.Value;
response.SetCookie(cookie);
}
return cookie;
}
else
{
return null;
}
}

/// <summary>
/// 获得Cookie
/// </summary>
/// <param name="cookieName"></param>
/// <returns></returns>
public HttpCookie GetCookie(string cookieName)
{
bool isReusable = HttpContext.CurrentHandler.IsReusable;
HttpRequest request = System.Web.HttpContext.Current.Request;
if (request != null)
return request.Cookies[cookieName];
return null;
}
/// <summary>
/// 删除Cookies
/// </summary>
/// <param name="cookieName"></param>
/// <param name="key"></param>
public static void RemoveCookie(string cookieName, string key)
{
HttpResponse response = System.Web.HttpContext.Current.Response;
if (response != null)
{
HttpCookie cookie = response.Cookies[cookieName];
if (cookie != null)
{
if (!string.IsNullOrEmpty(key))
cookie.Values.Remove(key);
else
response.Cookies.Remove(cookieName);
}
}

}
#endregion