This message is sent by an application before adding a large number of items to the list box portion of a combo box. This message allocates memory for storing list box items.
At a Glance
| Header file: | Winuser.h |
| Windows CE versions: | 1.0 and later |
Syntax
CB_INITSTORAGE wParam = (WPARAM)(int) cItems;
lParam = (LPARAM)(DWORD) cb;
Parameters
cItems
Specifies the number of items to add.
cb
Specifies the amount of memory to allocate for item strings, in bytes.
Return Values
The total number of items for which memory has been pre-allocated—that is, the total number of items added by all successful CB_INITSTORAGE messages—indicates success. CB_ERRSPACE indicates failure.
Windows NT: For Windows NT version 4.0, this message does not allocate the specified amount of memory; however, it always returns the value specified in the cItems parameter. For Windows NT version 5.0, the message allocates memory and returns the success and error values described above.
Remarks
The lParam parameter is unused in Windows CE.
The CB_INITSTORAGE message helps speed up the initialization of combo boxes that have a large number of items (over 100). It reserves the specified amount of memory so that subsequent CB_ADDSTRING, CB_INSERTSTRING, and CB_DIR messages take the shortest possible time. You can use estimates for the cItems and cb parameters. If you overestimate, the extra memory is allocated, if you underestimate, the normal allocation is used for items that exceed the requested amount.
See Also