The TCN_SELCHANGING notification message notifies a tab control's parent window that the currently selected tab is about to change. This message is sent in the form of a WM_NOTIFY message.
TCN_SELCHANGING
idTabCtl = (int) LOWORD(wParam);
lpnmhdr = (LPNMHDR) lParam;
Parameters
idTabCtl
Specifies the child window identifier of the tab control.
lpnmhdr
Pointer to an NMHDR structure. The hwndFrom member is the handle of the tab control. The idFrom member is the child window identifier of the tab control. The code member is TCN_SELCHANGING.
Return Values
Returns TRUE to prevent the selection from changing or FALSE to allow the selection to change.
Remarks
To determine the currently selected tab, use the TabCtrl_GetCurSel macro.
See Also