#Main = 0
#MDIChild = 1
If OpenWindow(#Main, 0, 0, 400, 300, "MDIGadget", #PB_Window_SystemMenu | #PB_Window_ScreenCentered | #PB_Window_SizeGadget | #PB_Window_MinimizeGadget | #PB_Window_MaximizeGadget)
  If CreateMenu(#Main, WindowID(#Main))
    MenuTitle("Menu index 0")
    MenuTitle("MDI windows menu")
    MenuItem(0, "self created item")
    MenuItem(1, "self created item")
    
    MDIGadget(0, 0, 0, 0, 0, 1, 2, #PB_MDI_AutoSize)
    For i = 1 To 8
      AddGadgetItem(0, #MDIChild+i, "child window "+Str(i))
    Next 
    ; add gadgets here...
    UseGadgetList(WindowID(#Main)) ; go back to the main window gadgetlist
  EndIf
  Repeat : Until WaitWindowEvent()=#PB_Event_CloseWindow
EndIf

OpenWindow(0, 0, 0, 800, 600, "", #PB_Window_ScreenCentered)
OpenWindow(1, 0, 0, 80, 60, "",#PB_Window_WindowCentered, WindowID(0))

SetParent_(WindowID(1), WindowID(0))
 
Repeat
  Event=WaitWindowEvent()
Until Event=#PB_Event_CloseWindow

OpenWindow(0, 0, 0, 800, 600, "Главное окно",#PB_Window_Invisible | #PB_Window_SystemMenu | #PB_Window_MinimizeGadget | #PB_Window_MaximizeGadget | #PB_Window_ScreenCentered)
OpenWindow(1, 0, 0, 280, 60, "Дочернее окно",#PB_Window_Invisible | #PB_Window_SystemMenu | #PB_Window_MinimizeGadget | #PB_Window_MaximizeGadget | #PB_Window_SizeGadget, WindowID(0))

SetParent_(WindowID(1), WindowID(0))
HideWindow(0,0)
HideWindow(1,0)
    
Repeat
  Event=WaitWindowEvent()
Until Event=#PB_Event_CloseWindow

Procedure WindowCallback(hWnd, Msg, wParam, lParam)
  
  Select Msg
    Case #WM_CLOSE 
      DestroyWindow_(hWnd) 
    Case #WM_DESTROY 
      PostQuitMessage_(0) : Result  = 0 
    Default 
      Result  = DefWindowProc_(hWnd, Msg, wParam, lParam) 
  EndSelect 
  
  ProcedureReturn Result 
EndProcedure  

Procedure Win(Class.s, Win)
  wc.WNDCLASSEX 
  wc\cbsize        = SizeOf(WNDCLASSEX) 
  wc\lpfnWndProc   = @WindowCallback() 
  wc\hCursor       = LoadCursor_(0, #IDC_ARROW) 
  wc\hbrBackground = #COLOR_WINDOW
  wc\lpszClassName = @Class 
  RegisterClassEx_(@wc) 
  ProcedureReturn CreateWindowEx_(0, Class, "", #WS_VISIBLE|#WS_SYSMENU | #WS_MINIMIZEBOX|#WS_MAXIMIZEBOX|#WS_SIZEBOX, 0, 0, 200, 120, Win,0,  0, 0)
EndProcedure

hWnd=Win("Win1", 0)
w=Win("Win1", hWnd)

SetParent_(w, hWnd)

While GetMessage_(msg.MSG, #Null, 0, 0) 
  TranslateMessage_(msg) 
  DispatchMessage_(msg) 
Wend

Case #WM_SIZE 
     RedrawWindow_(w, 0, 0, #RDW_ALLCHILDREN|#RDW_UPDATENOW) ; Уменьшаем мерцания окна с помошью Api при изменении его размеров.

Declare WindowCallback(hWnd, Msg, wParam, lParam)

Procedure WinChild(Class.s, x, y, width, height,Caption$,Win)
  wc.WNDCLASSEX 
  wc\cbsize        = SizeOf(WNDCLASSEX) 
  wc\lpfnWndProc   = @WindowCallback() 
  wc\hCursor       = LoadCursor_(0, #IDC_ARROW) 
  wc\hbrBackground = #COLOR_WINDOW
  wc\lpszClassName = @Class 
  RegisterClassEx_(@wc) 
  ProcedureReturn CreateWindowEx_(0, Class, Caption$, #WS_VISIBLE|#WS_SYSMENU | #WS_MINIMIZEBOX|#WS_MAXIMIZEBOX|#WS_SIZEBOX, x, y, width, height, Win,0,  0, 0)
EndProcedure

Procedure WinMain(Class.s, x, y, width, height,Caption$, Win)
  wc.WNDCLASSEX 
  wc\cbsize        = SizeOf(WNDCLASSEX) 
  wc\lpfnWndProc   = @WindowCallback() 
  wc\hCursor       = LoadCursor_(0, #IDC_ARROW) 
  wc\hbrBackground = #COLOR_WINDOW
  wc\lpszClassName = @Class 
  RegisterClassEx_(@wc) 
  ProcedureReturn CreateWindowEx_(0, Class, Caption$, #WS_VISIBLE|#WS_SYSMENU | #WS_MINIMIZEBOX|#WS_MAXIMIZEBOX|#WS_SIZEBOX, x, y, width, height, Win,0,  0, 0)
EndProcedure


hWnd=WinMain("Win1", 0, 0, 800, 600,"Средствами WinAPI - "+Chr(34)+" Главное окно "+Chr(34), 0)
w=WinChild("Win2", 0, 0, 280, 60, "Дочернее окно", hWnd)

SetParent_(w, hWnd)

While GetMessage_(msg.MSG, #Null, 0, 0) 
  TranslateMessage_(msg) 
  DispatchMessage_(msg)
  
Wend
Procedure WindowCallback(hWnd, Msg, wParam, lParam)
  
  Select Msg
    Case #WM_CLOSE 
      DestroyWindow_(hWnd) 
    Case #WM_DESTROY 
      PostQuitMessage_(0) : Result  = 0 
    Case #WM_SIZE 
     Debug w  
     RedrawWindow_(w, 0, 0, #RDW_ALLCHILDREN|#RDW_UPDATENOW) ; Уменьшаем мерцания окна с помошью Api при изменении его размеров.
     
    Default 
      Result  = DefWindowProc_(hWnd, Msg, wParam, lParam) 
  EndSelect 
  
  ProcedureReturn Result 
EndProcedure