VB Migration Partner’s support library hides most of the differences between the VB6 and the .NET versions of the Toolbar control, but not all of them. In most cases the remaining differences should have no impact on migrated programs. Here’s their complete list:

1. The Caption property of all placeholder buttons is always set to “” (empty string.)
2. The width of Button that contain text isn’t necessarily migrated correctly, because VB6 and VB.NET use different margin and arrangements for buttons that contain text and graphics.
3. When you click a VB6 Button, the event sequence is: MouseDown, MouseUp, Click, DoubleClick. In the same circumstances, the .NET control fires these events: MouseDown, Click, ButtonClick, MouseUp.
4. When you double click an area of the toolbar where there are no buttons, the event sequence is: MouseDown, MouseUp, Click, DblClick, MouseUp. (Notice that there is one MouseDown but two MouseUp.) In the same circumstances, the .NET control fires these events: MouseDown, Click, MouseUp, MouseDown, DblClick, MouseUp.
5. VB6 ignores the attempt to add a ButtonMenu element to a Button object whose style is different from tbrDropDown (more precisely, the Add method returns a ButtonMenu object but this element isn’t visible). In the same circumstances, the Add method throws an exception under VB.NET