The TCM_GETCURFOCUS message returns the index of the item that has the focus in a tab control. You can send this message explicitly or by using the TabCtrl_GetCurFocus macro.
TCM_GETCURFOCUS
wParam = 0; // not used; must be zero
lParam = 0; // not used; must be zero
Return Values
Returns the index of the tab item that has the focus
Remarks
The item that has the focus may be different than the selected item.
See Also