GetWindowTextLength

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This 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
);

Parameters

hWnd

Handle to the window or control.

Return Values

The length, in characters, of the text 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. Zero indicates that the window has no text. To get extended error information, call GetLastError.

Remarks

If the target window is owned by the current process, GetWindowTextLengthcauses a WM_GETTEXTLENGTHmessage to be sent to the specified window or control.

Under certain conditions, the GetWindowTextLengthfunction 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 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 GetWindowTextLengthwith a window whose window procedure is Unicode, or the Unicode version of GetWindowTextLengthwith a window whose window procedure is ANSI.

To obtain the exact length of the text, use the WM_GETTEXT, LB_GETTEXT, or CB_GETLBTEXTmessages, or the GetWindowTextfunction.

Requirements

Runs on	Versions	Defined in	Include	Link to
Windows CE OS	1.0 and later	Winuser.h

Note This API is part of the complete Windows CE OS package as provided by Microsoft. The functionality of a particular platform is determined by the original equipment manufacturer (OEM) and some devices may not support this API.