If anybody have ever done with Dotnetbar interface please help me this question.

I want :

Code:
For Each ctrl As ButtonItem In Ribbonbar1.Controls
                            MsgBox(ctrl)
                        Next
But msgbox didnt show.

I checked and know Ribbonbar1.Controls.count = 0. I dont know why.
I placed many controls to it. If Ribbonbar1 is not a collection why does it have controls propety ?