GetWindowTextLength
The GetWindowTextLength
function retrieves the length, in characters, of the specified window s title
bar text (if the window has a title bar). If the specified window is a control,
the function retrieves the length of the text within the control.
int GetWindowTextLength(
|
HWND hWnd |
// handle of window
or control with text |
|
); |
|
Parameters
hWnd
Identifies
the window or control.
Return Values
If the
function succeeds, the return value is the length, in characters, of the text.
Under certain conditions, this value may actually be greater than the length of
the text. For more information, see the following Remarks section.
If the window
has no text, the return value is zero. To get extended error information, call GetLastError.
Remarks
This function
causes a WM_GETTEXTLENGTH
message to be sent to the specified window or control.
Under certain
conditions, the GetWindowTextLength function may return a value that 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 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. It
can also occur when an application uses the ANSI flavor of GetWindowTextLength
with a window whose window procedure is Unicode, or the Unicode flavor with a
window whose window procedure is ANSI.
To obtain the
exact length of the text, use the WM_GETTEXT, LB_GETTEXT, or CB_GETLBTEXT
messages, or the GetWindowText function.
See Also