如何在aspx页面中隐藏ASP.NET自定义控件的属性？

I'm writing ASP.NET custom control, and I want it to have a few properties which should be visible only from code behind during run-time - I mean, these properties should not be visible both in a designer and in a aspx code of page containing this control. I've tried to use following attributes:I'm writing ASP.NET custom control, and I want