[Overview][Constants][Types][Classes][Procedures and functions][Variables][Index] Reference for unit 'InterfaceBase' (#lcl)

TWidgetSet.GetWindowLong

Returns the attributes of a window.

Declaration

Source position: winapih.inc line 158

public function TWidgetSet.GetWindowLong(

  Handle: HWND;

  int: Integer

):PtrInt; virtual;

Arguments

Handle

  

The window handle.

int

  

Offset of the attribute.

Function result

The attribute.

Description

The following attributes are defined:

GWL_EXSTYLE
extended window style flags. See CreateWindowEx.
GWL_STYLE
window style flags.
GWL_WNDPROC
the window procedure (address or handle). See CallWindowProc.
GWL_HINSTANCE
handle of the application instance.
GWL_HWNDPARENT
handle of the parent window.
GWL_ID
the identifier of the window.
GWL_USERDATA
user data associated with the window.

The following attributes are also available when the window is a dialog box:

DWL_DLGPROC
the dialog box procedure (address or handle).
DWL_MSGRESULT
the return value of a message processed in the dialog box procedure.
DWL_USER
extra application information.

GWL_USERDATA and DWL_USER are the base offsets of user added attributes. The second user attribute can be access with an additional offset of 4, and so on.

The latest version of this document can be found at lazarus-ccr.sourceforge.net.