Question

I need to create a form (using CreateWindow functions) without any help from the VCL (or any visual control) only using the Windows API.

This form will have an InputBox, a Button and a BitMap (like TImage does).

I was not able to find any sample on internet. Does anyone know a good place where I can download a sample besides MSDN?

Answer 1

This is a sample App which uses only the WinApi to create Windows with an static, edit and button, I let you the display of the BitMap display as exercise for you.

uses
  Windows,
  Messages,
  SysUtils;

var
  Msg        : TMSG;
  LWndClass  : TWndClass;
  hMainHandle: HWND;
  hButton    : HWND;
  hStatic    : HWND;
  hEdit      : HWND;
  hFontText  : HWND;
  hFontButton: HWND;

procedure ReleaseResources;
begin
  DestroyWindow(hButton);
  DestroyWindow(hStatic);
  DestroyWindow(hEdit);
  DeleteObject(hFontText);
  DeleteObject(hFontButton);
  PostQuitMessage(0);
end;

function WindowProc(hWnd,Msg:Longint; wParam : WPARAM; lParam: LPARAM):Longint; stdcall;
begin
  case Msg of
      WM_COMMAND: if lParam = hButton then
                    MessageBox(hMainHandle,'You pressed the button Hello', 'Hello',MB_OK or MB_ICONINFORMATION);
      WM_DESTROY: ReleaseResources;
  end;
  Result:=DefWindowProc(hWnd,Msg,wParam,lParam);
end;

begin
  //create the window
  LWndClass.hInstance := hInstance;
  with LWndClass do
    begin
      lpszClassName := 'MyWinApiWnd';
      Style         := CS_PARENTDC or CS_BYTEALIGNCLIENT;
      hIcon         := LoadIcon(hInstance,'MAINICON');
      lpfnWndProc   := @WindowProc;
      hbrBackground := COLOR_BTNFACE+1;
      hCursor       := LoadCursor(0,IDC_ARROW);
    end;

  RegisterClass(LWndClass);
  hMainHandle := CreateWindow(LWndClass.lpszClassName,'Window Title', WS_CAPTION or WS_MINIMIZEBOX or WS_SYSMENU or WS_VISIBLE, (GetSystemMetrics(SM_CXSCREEN) div 2)-190,
      (GetSystemMetrics(SM_CYSCREEN) div 2)-170, 386,200,0,0,hInstance,nil);

  //Create the fonts to use
  hFontText := CreateFont(-14,0,0,0,0,0,0,0,DEFAULT_CHARSET,OUT_DEFAULT_PRECIS,CLIP_DEFAULT_PRECIS,DEFAULT_QUALITY,VARIABLE_PITCH or FF_SWISS,'Tahoma');
  hFontButton := CreateFont(-14,0,0,0,0,0,0,0,DEFAULT_CHARSET,OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS,DEFAULT_QUALITY,VARIABLE_PITCH or FF_SWISS,'Tahoma');

  //create the static
  hStatic:=CreateWindow('Static','This is static text, like a TLabel',WS_VISIBLE or WS_CHILD or SS_LEFT, 10,10,360,44,hMainHandle,0,hInstance,nil);
  SendMessage(hStatic,WM_SETFONT,hFontText,0);

  //create the edit
  hEdit:=CreateWindowEx(WS_EX_CLIENTEDGE,'Edit','This a Edit like and TEdit', WS_VISIBLE or WS_CHILD or ES_LEFT or ES_AUTOHSCROLL,10,35,360,23,hMainHandle,0,hInstance,nil);
  SendMessage(hEdit,WM_SETFONT,hFontText,0);

  //create the button
  hButton:=CreateWindow('Button','Hello', WS_VISIBLE or WS_CHILD or BS_PUSHBUTTON or BS_TEXT, 10,130,100,28,hMainHandle,0,hInstance,nil);
  SendMessage(hButton,WM_SETFONT,hFontButton,0);

  //message loop
  while GetMessage(Msg,0,0,0) do
  begin
    TranslateMessage(Msg);
    DispatchMessage(Msg);
  end;

end.