Enumerate Windows

posted 16 Mar 2010, 08:39 by Delphi Basics
In computing, a window is a visual area containing some kind of user interface. It usually has a rectangular shape.[1]  It displays the output of and may allow input to one or more processes.

Read more: http://en.wikipedia.org/wiki/Window_%28computing%29

type
  PMyEnumParam = ^TMyEnumParam;
  TMyEnumParam = record
    lb: TListbox;
  end;

function GetWindows(const hWnd: Longword; Param: PMyEnumParam): LongBool;
  stdcall;
var
  Len: Longint;
  S: string;
begin
  Result := True;
  if not (IsWindow(hWnd) and IsWindowVisible(hWnd)) then
    Exit;
  Len := SendMessage(hWnd, WM_GETTEXTLENGTH, 0, 0);
  if Len > 0 then
  begin
    SetLength(S, Len);
    SendMessage(hWnd, WM_GETTEXT, Len + 1, Longint(Pchar(S)));
    Param.lb.Items.Add(s);
  end;
  // mit Result = False kann die Callbackfunktion vorzeitig verlassen werden
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  Param: TMyEnumParam;
begin
  Param.lb := Listbox1;
  EnumWindows(@GetWindows, LPARAM(@Param));
end;
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