Как с помощью API поместить Label на Form?

Вариант 1:

Author: Baa

Source: Vingrad.ru https://forum.vingrad.ru

var 
  hLabel : HWND ;
...
hLabel := CreateWindow ( 'STATIC', 'test', WS_CHILD or WS_VISIBLE,
                         0, 0, 200, 40, hWnd, NULL, hInstance, NULL ); 

Примечание: Vit

Скорее всего последний параметр не "NULL", а "Nil" (NULL в паскале - вариант для обозначения пустого поля в базе данных)

Вариант 2:

Author: alex-co

Source: Vingrad.ru https://forum.vingrad.ru

program Project1;

uses
  Windows,
  Messages;
const
  myClassName= 'myWindow';
var
  handleWnd, Label1 : THandle;
  WndClass: TWndClass;
  Msg: TMsg;
function WindowProc(Window: HWnd; AMessage, WParam,
  LParam: Longint): Longint; stdcall;
begin
  WindowProc:= DefWindowProc(Window, AMessage, WParam, LParam);
  case AMessage of
    {WM_COMMAND: if lParam = Button1 then
      MessageBox( 0, 'Вы нажали кнопку!', 'Информация', MB_OK or MB_ICONINFORMATION); }
    WM_DESTROY: Halt;
  end;
end;

begin
  with WndClass do
  begin
    hInstance := hInstance;
    lpszClassName:= myClassName;
    style := cs_hRedraw or cs_vRedraw;
    hbrBackground:= color_btnface +1;
    lpfnWndProc := @WindowProc;
    hCursor := LoadCursor(0, idc_Arrow);
    hIcon := LoadIcon(0, IDI_EXCLAMATION);
    lpszMenuName := NIL;
    cbWndExtra := 0;
    cbClsExtra := 0;
  end;
  RegisterClass( WndClass );
  handleWnd:= CreateWindow(myClassName, 'Hажми кнопку', ws_OverlappedWindow,
                           400, 300, 200, 100, 0, 0, hInstance, NIL);
  if handleWnd = 0 then
  begin
    MessageBox( 0, 'Error', NIL, MB_OK );
    Exit;
  end;
  Label1:= CreateWindow( 'Label', 'Text', WS_VISIBLE or WS_CHILD or WM_SETTEXT,
                         20, 10, 60, 23, handleWnd, 0, hInstance, nil);
  ShowWindow(handleWnd, SW_SHOW);
  UpdateWindow(handleWnd);
  while GetMessage(Msg, handleWnd, 0, 0) do
  begin
    TranslateMessage(Msg) ;
    DispatchMessage(Msg) ;
  end;
end.