The tab control now supports extended styles. These styles are manipulated using the TCM_GETEXTENDEDSTYLE and TCM_SETEXTENDEDSTYLE messages and should not be confused with extended window styles that are passed to CreateWindowEx.
Constant
Description
TCS_EX_FLATSEPARATORS
Version 4.71. The tab control will draw separators between the tab items. This extended style only affects tab controls that have the TCS_BUTTONS and TCS_FLATBUTTONS styles. By default, creating the tab control with the TCS_FLATBUTTONS style sets this extended style. If you do not require separators, you should remove this extended style after creating the control.
TCS_EX_REGISTERDROP
Version 4.71. The tab control generates TCN_GETOBJECT notification codes to request a drop target object when an object is dragged over the tab items in the control. The application must call CoInitialize or OleInitialize before setting this style.