TCM_SETITEMEXTRA
The
TCM_SETITEMEXTRA message sets the number of bytes per tab reserved for
application-defined data in a tab control. You can send this message explicitly
or by using the TabCtrl_SetItemExtra macro.
TCM_SETITEMEXTRA
wParam = (WPARAM) (int) cb; // number of extra bytes
lParam = 0; // not used; must be zero
Parameters
cb
Number of
extra bytes.
Return Values
Returns TRUE
if successful or FALSE otherwise.
Remarks
By default,
the number of extra bytes is four. An application that changes the number of
extra bytes cannot use the TC_ITEM structure to retrieve and set the
application-defined data for a tab. Instead, you must define a new structure
that consists of the TC_ITEMHEADER structure followed by
application-defined members.
An
application should only change the number of extra bytes when a tab control
does not contain any tabs.
See Also