http://stuff.mtst.at/index.php?a=get&f=Zeichnung1.jpg

Hi

In the picture above there are 2 classes "DropDownList" and "CheckBoxList" which inherit "ListControl". They are inside the .net framework.

I would like to implement a CustomListControl, with additional attributes (x,y). CustomListControl should have all the attributes and methods that ListControl has. So CustomListControl inhertis ListControl. And the two base classes should inherit CustomListControl.

So I can use a CustomListControl[Array], work with the x and y attributes and don't need to care if it is a CheckBoxList or a DropDownList. The Problem is that I can't edit the .net framework classes.

And I can't create a CustomDropDownList class which has all the attributes and methods that DropDownList has (inheritance) and inherit my CustomDropDownList from CustomListControl.