A WinButton control can only be assigned as the dropdown button of one control.
If the WinButton control is part of the SideButtons collection of a WinTextBox (or derived) control, and is assigned as the WinTextBox control's DropDownButton, the default value of the AutoSizeMode property will be AutoSizeMode.ScrollBarWidth.
Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2