TabCtrl_SetItemExtra macro (commctrl.h)
Sets the number of bytes per tab reserved for application-defined data in a tab control. You can use this macro or send the TCM_SETITEMEXTRA message explicitly.
C++
BOOL TabCtrl_SetItemExtra(
HWND hwndTC,
int cb
);
hwndTC
Type: HWND
Handle to the tab control.
cb
Type: int
Number of extra bytes.
Type: BOOL
Returns TRUE if successful, or FALSE otherwise.
By default, the number of extra bytes is four. An application that changes the number of extra bytes cannot use the TCITEM structure to retrieve and set the application-defined data for a tab. Instead, you must define a new structure that consists of the TCITEMHEADER 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.
| Requirement | Value |
|---|---|
| Minimum supported client | Windows Vista [desktop apps only] |
| Minimum supported server | Windows Server 2003 [desktop apps only] |
| Target Platform | Windows |
| Header | commctrl.h |