DX Studio - I need some help

[Paul Squires]

A fellow FireFly user is having trouble unloading an OCX from memory when the application ends. The exe process continues to run and stays in memory.

The DX Studio player control can be found here:  http://www.dxstudio.com/download.aspx

A sample project is attached.

Note: If the code in WM_DESTROY is executed elsewhere other than in WM_DESTROY then the control unloads and the exe does not remain in memory.

Any ideas why it won't work properly via the WM_DESTROY handler?

Thanks!

[José Roca]

Code Select Expand


Function FORM1_WM_DESTROY ( _
                          hWndForm      As Dword _  ' handle of Form
                          ) As Long



   Local pDispatch As IDXStudioPlayer

   ' Get a reference to the DXStudio control and set the properties

   pDispatch = OC_GetDispatch(HWND_FORM1_OCXCONTROL1)

   If IsObject(pDispatch) Then
      pDispatch.ManualShutDown
      pDispatch = Nothing
   End If

End Function


Do error checking, i.e. check if IsObject(pDispatch) returns true and if pDispatch.ManualShutDown returns true.

[Frank Applin]

There seems to be a timing issues as to when messages get processed. If I check the return value and pop up a messagebox, the ManualShutdown happens and the executable is not left in memory. If I comment out the messagebox then the executable is still left in memory.

'--------------------------------------------------------------------------------
Function FORMMOVECHESSPIECES_WM_CLOSE ( _
                        hWndForm As Dword _  ' handle of Form
                        ) As Long
   Local ret As Long
   Local pDispatch As IDXStudioPlayer
   pDispatch = OC_GetDispatch(HWND_FORMMOVECHESSPIECES_OCXCONTROL1)
   
   If IsObject(pDispatch) Then
      Call pDispatch.ManualShutdown() To ret
      MsgBox "return value " + Str$(ret)
      pDispatch = Nothing
   End If               
End Function

[Cho Sing Kum]

Will a DoEvent at the right place help?

[José Roca]

There seems to be a timing issues as to when messages get processed.

Maybe it is slow closing and when the program finishes can't unload it because it is still busy. Try to do the shut down in WM_CLOSE instead of WM_DESTROY.

[Frank Applin]

It leaves it in memory in either WM_CLOSE or WM_DESTROY. I'm trying to re-create it in straight PB and it seems to get unloaded fine from straight PB.

[Frank Applin]

This is based on one of Jose' examples (Thanks, Jose') and works great. I don't even do a shutdown at all.

  #DIM ALL
  #DEBUG ERROR ON
  #INCLUDE "win32api.inc"


  %ID_OCX = 1001
  %ID_NORTH = 1002
  %ID_EAST = 1003
  %ID_SOUTH = 1004
  %ID_WEST = 1005
  %ID_RESET = 1006


  GLOBAL hDlg AS DWORD
  GLOBAL hOcx AS DWORD
  GLOBAL oOcx AS DISPATCH

' *********************************************************************************************
' ATLAPI_(BOOL) AtlAxWinInit( );
' This function initializes ATL's control hosting code by registering the "AtlAxWin7" and
' "AtlAxWinLic7" window classes plus a couple of custom window messages.
' Return Value: TRUE, if the initialization of the control hosting code was successful; otherwise FALSE.
' Remarks: This function must be called before using the ATL control hosting API. Following a
' call to this function, the "AtlAxWin" window class can be used in calls to CreateWindow or
' CreateWindowEx, as described in the Platform SDK.
' *********************************************************************************************
  DECLARE FUNCTION AtlAxWinInit LIB "ATL.DLL" ALIAS "AtlAxWinInit" () AS LONG
' *********************************************************************************************

' *********************************************************************************************
' inline BOOL AtlAxWinTerm( );
' This function uninitializes ATL's control hosting code by unregistering the "AtlAxWin7" and
' "AtlAxWinLic7" window classes.
' This function simply calls UnregisterClass as described in the Platform SDK.
' Call this function to clean up after all existing host windows have been destroyed if you
' called AtlAxWinInit and you no longer need to create host windows. If you don't call this
' function, the window class will be unregistered automatically when the process terminates.
' Return Value: If the function succeeds, the return value is nonzero.
' *********************************************************************************************
  DECLARE FUNCTION AtlAxWinTerm () AS LONG
' *********************************************************************************************
  FUNCTION AtlAxWinTerm () AS LONG
    UnregisterClass ("AtlAxWin", GetModuleHandle(BYVAL %NULL))
  END FUNCTION
' *********************************************************************************************

' *********************************************************************************************
' ATLAPI AtlAxGetControl (HWND h, IUNKNOWN** pp);
' Obtains a direct interface pointer to the control contained inside a specified window given its handle.
' **********************************************************************************************
  DECLARE FUNCTION AtlAxGetControl LIB "ATL.DLL" ALIAS "AtlAxGetControl" _
     ( _
     BYVAL hWnd AS DWORD, _   ' [in] A handle to the window that is hosting the control.
     BYREF pp AS DWORD _      ' [out] The IUnknown of the control being hosted.
  ) AS DWORD
' *********************************************************************************************

' *********************************************************************************************
' Puts the address of an object in a variant and marks it as containing a dispatch variable
' *********************************************************************************************
  SUB AtlMakeDispatch ( _
     BYVAL lpObj AS DWORD, _                        ' Address of the object instance
     BYREF vObj AS VARIANT _                        ' Variant to contain this address
     ) EXPORT

     LOCAL lpvObj AS VARIANTAPI PTR                 ' Pointer to a VARIANTAPI structure
     LET vObj = EMPTY                               ' Make sure is empty to avoid memory leaks
     lpvObj = VARPTR(vObj)                          ' Get the VARIANT address
     @lpvObj.vt = %VT_DISPATCH                      ' Mark it as containing a dispatch variable
     @lpvObj.vd.pdispVal = lpObj                    ' Set the dispatch pointer address

  END SUB
' *********************************************************************************************

' *********************************************************************************************
' Converts a Windows error code in a message string
' *********************************************************************************************
  FUNCTION WinErrorMsg (BYVAL dwError AS DWORD) AS STRING

     LOCAL pBuffer   AS ASCIIZ PTR
     LOCAL ncbBuffer AS DWORD
     LOCAL sText AS STRING

     ncbBuffer = FormatMessage(%FORMAT_MESSAGE_ALLOCATE_BUFFER _
                 OR %FORMAT_MESSAGE_FROM_SYSTEM OR %FORMAT_MESSAGE_IGNORE_INSERTS, _
                 BYVAL %NULL, dwError, BYVAL MAKELANGID(%LANG_NEUTRAL, %SUBLANG_DEFAULT), _
                 BYVAL VARPTR(pBuffer), 0, BYVAL %NULL)

     IF ncbBuffer THEN
         sText = PEEK$(pBuffer, ncbBuffer)
         sText = REMOVE$ (sText, ANY CHR$(13) + CHR$(10))
         LocalFree pBuffer
     ELSE
         sText = "Unknmown error - Code "+ HEX$(dwError,
     END IF

     FUNCTION = sText

  END FUNCTION
' *********************************************************************************************

' *********************************************************************************************
'                                  M A I N     P R O G R A M
' *********************************************************************************************

' *********************************************************************************************
' Main dialog callback
' *********************************************************************************************
  CALLBACK FUNCTION MainDlgProc()

     LOCAL rc AS RECT
     LOCAL r AS LONG
     LOCAL x AS LONG
     LOCAL y AS LONG
     LOCAL xx AS LONG
     LOCAL yy AS LONG


     SELECT CASE CBMSG

        CASE %WM_SIZE
           'GetClientRect CBHNDL, rc
           'x = rc.nLeft : y = rc.nTop
           'xx = rc.nRight - 100 'rc.nLeft
           'yy = rc.nBottom - 100 'rc.nTop
           'MoveWindow hOcx, x, y, xx, yy, %TRUE

        CASE %WM_DESTROY
           PostQuitMessage 0

        CASE %WM_COMMAND
           SELECT CASE CBCTL
              CASE %IDCANCEL
                 IF CBCTLMSG = %BN_CLICKED OR CBCTLMSG = 1 THEN
                    DIALOG END CBHNDL, 0
                 END IF
           END SELECT

     END SELECT

  END FUNCTION
' *********************************************************************************************

CALLBACK FUNCTION ButtonResetCallback() AS LONG
    IF CB.MSG = %WM_COMMAND AND CB.CTLMSG = %BN_CLICKED THEN
        '...Process the click event here
        LOCAL temp AS VARIANT
        temp = "scenes.scene_1.script.ResetPieces()"
        OBJECT CALL oOcx.Send(temp)
        FUNCTION = 1
    END IF
END FUNCTION

CALLBACK FUNCTION ButtonNorthCallback() AS LONG
    IF CB.MSG = %WM_COMMAND AND CB.CTLMSG = %BN_CLICKED THEN
        '...Process the click event here
        LOCAL temp AS VARIANT
        temp = "scenes.scene_1.script.MoveNorth('BlackQueen')"
        OBJECT CALL oOcx.Send(temp)
        FUNCTION = 1
    END IF
END FUNCTION

CALLBACK FUNCTION ButtonEastCallback() AS LONG
    IF CB.MSG = %WM_COMMAND AND CB.CTLMSG = %BN_CLICKED THEN
        '...Process the click event here
        LOCAL temp AS VARIANT
        temp = "scenes.scene_1.script.MoveEast('BlackQueen')"
        OBJECT CALL oOcx.Send(temp)
        FUNCTION = 1
    END IF
END FUNCTION

CALLBACK FUNCTION ButtonSouthCallback() AS LONG
    IF CB.MSG = %WM_COMMAND AND CB.CTLMSG = %BN_CLICKED THEN
        '...Process the click event here
        LOCAL temp AS VARIANT
        temp = "scenes.scene_1.script.MoveSouth('BlackQueen')"
        OBJECT CALL oOcx.Send(temp)
        FUNCTION = 1
    END IF
END FUNCTION

CALLBACK FUNCTION ButtonWestCallback() AS LONG
    IF CB.MSG = %WM_COMMAND AND CB.CTLMSG = %BN_CLICKED THEN
        '...Process the click event here
        LOCAL temp AS VARIANT
        temp = "scenes.scene_1.script.MoveWest('BlackQueen')"
        OBJECT CALL oOcx.Send(temp)
        FUNCTION = 1
    END IF
END FUNCTION

' *********************************************************************************************
' Main
' *********************************************************************************************
  FUNCTION PBMAIN

     LOCAL hInst AS DWORD
     LOCAL hr AS DWORD
     LOCAL OcxName AS ASCIIZ * 255
     LOCAL pUnk AS DWORD
     LOCAL vVar AS VARIANT
     LOCAL vIdx AS VARIANT
     LOCAL uMsg AS tagMsg
     LOCAL dwCookie AS DWORD

     OcxName = "DXStudioPlayerDLL.DXStudioPlayer.1"

    ' OcxName must be formatted in one of the following ways:
    ' ·  A ProgID such as "MSCAL.Calendar.7"
    ' ·  A CLSID such as "{8E27C92B-1264-101C-8A2F-040224009C02}"
    ' ·  A URL such as "http://www.microsoft.com"
    ' ·  A reference to an Active document such as "file://\\Documents\MyDoc.doc"
    ' ·  A fragment of HTML such as "MSHTML:<HTML><BODY>This is a line of text</BODY></HTML>"
    ' Note   "MSHTML:" must precede the HTML fragment so that it is designated as being an MSHTML stream.

     hInst = GetModuleHandle(BYVAL %NULL)

     AtlAxWinInit   ' // Initializes ATL

     DIALOG NEW 0, "Test DX Studio",,, 800, 600, %WS_OVERLAPPEDWINDOW, 0 TO hDlg
     CONTROL ADD "AtlAxWin", hDlg, %ID_OCX, OcxName, 0, 0, 550, 550, %WS_VISIBLE OR %WS_CHILD
     CONTROL ADD BUTTON, hDlg, %ID_NORTH, "North", 634, 143, 75, 25, , , CALL ButtonNorthCallback() ' Use default styles
     CONTROL ADD BUTTON, hDlg, %ID_EAST, "East", 680, 196, 75, 25, , , CALL ButtonEastCallback() ' Use default styles
     CONTROL ADD BUTTON, hDlg, %ID_NORTH, "South", 634, 243, 75, 25, , , CALL ButtonSouthCallback() ' Use default styles
     CONTROL ADD BUTTON, hDlg, %ID_NORTH, "West", 582, 196, 75, 25, , , CALL ButtonWestCallback() ' Use default styles
     CONTROL ADD BUTTON, hDlg, %ID_RESET, "Reset Pieces", 634, 327, 85, 25, , , CALL ButtonResetCallback() ' Use default styles

     CONTROL HANDLE hDlg, %ID_OCX TO hOcx

     AtlAxGetControl(hOcx, pUnk)
     AtlMakeDispatch(pUnk, vVar)
     SET oOcx = vVar

     vVar = "F:\PowerBasicClassicWindows9\Chessboard.dxstudio"
     OBJECT LET oOcx.src = vVar

    LOCAL temp AS    VARIANT
     OBJECT CALL oOcx.ManualInit
     temp = 0
     OBJECT LET oOcx.ManualCreateAndUpdate = temp


     DIALOG SHOW MODAL hDlg, CALL MainDlgProc TO hr



  Terminate:

     AtlAxWinTerm   ' // Uninitializes ATL
     SET oOcx = NOTHING

  END FUNCTION
' *********************************************************************************************