when inheriting Telerik RadGrid the Columns can't show it's children

[nan]

dear all: 
i do this
    public class MyRadGrid : Telerik.Web.UI.RadGrid
    {
but in the designer source the Columns of the MasterTableView can't IntelliSense his children auto.
please help me for these. thank you very much.

[nan]

or please tell me how the vs 2005 in designer source to known the children columns and auto show in tip type!

[nan]

i think i foud the reason of that, when we inherit radgrid, our dll only have the radgrid methods and properties, so vs 2005 can't foud the type of the columns need.