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. However, GetWindowTextLength cannot retrieve the length of the text of an edit control in another application.
int GetWindowTextLengthA( HWND hWnd );
A handle to the window or control.
Type: Type: int
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.
If the target window is owned by the current process, GetWindowTextLength 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 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. It can also occur when an application uses the ANSI version of GetWindowTextLength with a window whose window procedure is Unicode, or the Unicode version of GetWindowTextLength with a window whose window procedure is ANSI. For more information on ANSI and ANSI functions, see Conventions for Function Prototypes.
|Minimum supported client||Windows 2000 Professional [desktop apps only]|
|Minimum supported server||Windows 2000 Server [desktop apps only]|
|Header||winuser.h (include Windows.h)|