This message is sent by an application to retrieve the length of a string in a list box.
At a Glance
| Header file: | Winuser.h |
| Windows CE versions: | 1.0 and later |
Syntax
LB_GETTEXTLEN wParam = (WPARAM) index; lParam = 0;
Parameters
index
Zero-based index of the string.
Windows 95 and Windows 98: The wParam parameter is limited to 16-bit values. This means list boxes cannot contain more than 32,767 items. Although the number of items is restricted, the total size in bytes of the items in a list box is limited only by available memory.
Return Values
The length of the string, in characters and excluding the terminating null character, indicates success. Under certain conditions, this value may actually be greater than the length of the text. For more information, see the following Remarks section.
LB_ERR indicates that the index parameter does not specify a valid index.
Remarks
Under certain conditions, the return value is larger than the actual length of the text. This occurs with certain mixtures of ANSI and Unicode, and is due to the operating system allowing for the possible existence of double-byte character set (DBCS) characters within the text. The return value, however, will always be at least as large as the actual length of the text; you can thus always use it to guide buffer allocation. This behavior can occur when an application uses both ANSI functions and common dialogs, which use Unicode.
To obtain the exact length of the text, use the WM_GETTEXT, LB_GETTEXT, or CB_GETLBTEXT messages, or the GetWindowText function.
See Also