This control provides what the MFC ControlBar did, but the .Net ToolBar sorely left out. That is, it can be the container for any other type of control that fits within the boundaries of the bar, not just variations of a button. A neat feature of this control is that it will optionally automatically create a dropdown list for button controls that can't be seen because the user has shrunk the window containing the control bar. In addition, the LeerControlBar supports a vertical orientation in addition to the standard horizonatal orientation. The LeerFilePicker uses the vertical form to display the "favorites" buttons.