Get internal size of an (infragistics Winforms 10.2) control with scrollbars in C#

How can I get the internal size of an (infragistic开发者_开发百科s) control with scrollbars?

The control.Size contains the control size on the screen but how do I get the internal size (total size behind the scrollbars)?

Thanks,

Apparently, this is not possible: http://community.infragistics.com/forums/p/47007/251654.aspx#251654