question

There is in fact a WebControl class listed in the System.Web.UI.WebControls namespace:

http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.aspx 

This is just the base class for other controls in this namespace such as TextBox:

http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.textbox.aspx 

In practice, of course, you'd probably derive your custom control from TextBox, Button, Label etc rather than directly from WebControl though the latter would still be the ultimate base class of your custom control as well as its parent.

Hi Vulpes,

I agree that.

But if you see the namespace 

System.Web.UI.WebControls and inside that there is no WebControl class.

If you check the TextBox hierarchy, shows like System.Web.UI.WebControls.TextBox



Can you clarify me on this?

The correct answer is System.Web.UI.WebControls.

There is no namespace with the CustomControl or CustomControls.WebControls.

The custom controls are nothing but, we need to develop our controls on top of the existing ASP.Net web controls.

For example we have lot of controls like TextBox, Button.

If you have a requirement like TextBox should only accept the number then you need to develop your own custom controls.

The every control has its own class, so the custom control class has to be overriden that properties and events.

using System.Web.UI.WebControls

namespace MycustomControls
{
        public class TextBoxNumber : TextBox
        {
                //Write you logic here to implement custom textbox.
        }
}

You can get some example custom control in the following link:

http://sumedha7.blogspot.com/2008/07/derived-custom-controls-in-aspnet-20.html