注销时无法删除Cookie

//接口-注入控制器

  public interface IContext
{
    HttpRequestBase Request { get; }
    HttpResponseBase Response { get; }
}

//执行

  public class Context : IContext
{
    public HttpRequestBase Request { get { return new HttpRequestWrapper(HttpContext.Current.Request); } }
    public HttpResponseBase Response { get { return new HttpResponseWrapper(HttpContext.Current.Response); } }
}

//在登录时设置Cookie。SetCookie（_context，登录）;

public void SetCookie(IContext context, Login login)
{
        var loginDetails = new JavaScriptSerializer().Serialize(login);
        var cokie = new HttpCookie("login", login);
        context.Response.Cookies.Add(cokie);
}

//尝试注销。

    public ActionResult Logout()
    {
        foreach (var key in _context.Request.Cookies.AllKeys)
        {
            try
            {
                _context.Response.Cookies.Remove(key); //this didn't work

                //tried this even this is not working
                var login = new Login {Identity = "", LogIn = false};
                _login.SetCookie(_context, login);
            }
            catch (Exception e)
            {
            }
        }
        _context.Response.Cookies.Clear(); //this didn't work either

        return RedirectToAction("Index", "Login");
    }

在登录索引上，当我检查当前登录cookie值时，它始终具有已登录用户的值，只是没有将其设置为null或为空。我怀疑IContext的实现中存在问题。应该有塞特犬吗？没有把握..

也尝试过：

        var cokie = context.Request.Cookies["login"];
        cokie.Expires = DateTime.Now.AddDays(-2);
        cokie.Value = null;
        context.Response.Cookies.Add(cokie);