CB_DIR
wParam = (WPARAM) (UINT) uAttrs; /* file attributes */
lParam = (LPARAM) (LPCSTR) lpszFileSpec; /* address of filename */An application sends a CB_DIR message to add a list of filenames to the list box of a combo box.
uAttrs
Value of wParam. Specifies the attributes of the files to be added to the list box. It can be any combination of the following values:
| Value | Meaning |
| 0x0000 | File can be read from or written to. |
| 0x0001 | File can be read from but not written to. |
| 0x0002 | File is hidden and does not appear in a directory listing. |
| 0x0004 | File is a system file. |
| 0x0010 | The name pointed to by the lpszFileSpec parameter specifies a directory. |
| 0x0020 | File has been archived. |
| 0x4000 | All drives that match the name specified by the lpszFileSpec parameter are included. |
| 0x8000 | Exclusive flag. If the exclusive flag is set, only files of the specified type are listed. Otherwise, files of the specified type are listed in addition to files that do not match the specified type. |
lpszFileSpec
Value of lParam. Points to the null-terminated string that specifies the filename to add to the list. If the filename contains any wildcards (for example, *.*), all files that match and have the attributes specified by the uAttrs parameter will be added to the list.
The return value is the zero-based index of the last filename added to the list. The return value is CB_ERR if an error occurs. The return value is CB_ERRSPACE if insufficient space is available to store the new strings.
This example adds the names of all available drives to a combo box:
DWORD dwIndexLastItem;
dwIndexLastItem = SendDlgItemMessage(hdlg, ID_MYCOMBOBOX, CB_DIR,
0x4000 | 0x8000, (LPARAM) ((LPCSTR) "*"));