PB/DLL 2.0 -- 16 Bit Common Dialog

[Spencer Shearer]

I am converting some of my VB 3.0 application to DLL. I would
like to remove cmdialog.vbx from my application an make calls
directly to windows for common dialog routines, specifically
File Open, File Save As. I have searched the PB forums but cannot
find any examples to work with. Any suggestions or examples will
help.

Thanks...
Spencer

[Spencer Shearer]

I now have the File Open Dialog working in my application. I
found the cmdlg.bas file in the samp16 directory. I am calling
File Open routine with the following call:

cmuFileOpen (Me.hWnd)

Now what I would like to do is to pass into the PB/DLL dll that I
have created a user defined type. I am unsure how to do this
if it is possible.

Thanks for any help.
Spencer


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[Lance Edmonds]

Yes, you can use a VB UDT with PB - just pass the UDT by reference (BYREF) to the DLL.

However, you may have to take in account the alignment issues that 16-bit VB uses. There is a FAQ (on 32-bit VB and UDT alignment) in the FAQ forum on this BBS but I'm not sure how much of it (if any) applies to VB3. You may want to search your 16-bit VB documentation for more information.

In general, if you make all your UDT members 4 bytes long (or a multiple of 4 bytes), then your problems will be minimized.

JFYI: PB/DLL does not support dynamic (variable length) strings in UDT's - use ASCIIZ or fixed-length strings instead.


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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[Scott Hauser]

Spencer
As Lance mentioned it must be passed by reference. Simply create identical UDTs at both ends and pass them back and forth.

Lance
So far I haven't found any alignment issues in VB 4.0 (16 bit) either.


This is a sample of passing a two diminsional array of UDT from VB to PBDLL
PB CODE

$COMPILE DLL
$DIM ALL

TYPE Mytst
   FTxt AS STRING * 65
   FInt AS INTEGER
   FDbl AS DOUBLE
END TYPE

'====================== TWO DIM ARRAY OF TYPE FROM VB
' UDT1 is a 3X3 Array of Mytst(3, 3)
' VB 4.0 (16 Bit) passes this to a PBDLL 2.0

FUNCTION TEST_2DIM_UDT   (BYVAL UDT1    AS DWORD, _
                          BYVAL nSize   AS INTEGER, _
                          BYVAL szScnd  AS INTEGER _
                         ) EXPORT AS INTEGER
  
  DIM MYPTR AS Mytst PTR
  DIM A AS INTEGER, B AS INTEGER

  MYPTR = UDT1
   
  FOR A = 1 TO szScnd
      FOR B = 1 TO nSize
         @MYPTR[B of nSize, A of szScnd].FInt = B * A * 1000
         @MYPTR[B of nSize, A of szScnd].FDbl = B  / (A * B * 1000)
         @MYPTR[B of nSize, A of szScnd].FTxt = " Test String" + " B=" + STR$(B) + " and A=" + STR$(A)
      NEXT B
   NEXT A
   
   FUNCTION = -1
END FUNCTION

And VB CODE

Type UDTTst
  FTxt As String * 65
  FInt As Integer
  FDbl As Double
End Type

Public MyArr() As UDTTst

Declare Function TEST_2DIM_UDT Lib "1UDT.DLL" (MyArr As UDTTst, ByVal nSize%, ByVal szScnd%) As Integer
Sub Main()
 ChDir "C:\PBDLL20"
 ReDim Preserve MyArr(3, 3)
   

 XX = TEST_2DIM_UDT(MyArr(0, 0), 3, 3)
 Stop
   For A = 1 To 3
      For B = 1 To 3
        Debug.Print MyArr(B, A).FInt;
        Debug.Print MyArr(B, A).FDbl;
        Debug.Print MyArr(B, A).FTxt
      Next B
   Next A
   
   For A = 1 To 3
      For B = 1 To 3
        Debug.Print MyArr(B, A).FInt & MyArr(B, A).FDbl & MyArr(B, A).FTxt
      Next B
   Next A
 Stop
 'Check it out
End Sub

Hope this helps
Scott

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[Lance Edmonds]

I've confirmed that 16-bit VB uses byte-alignment so there are no likely alignment issues here.

It is only 32-bit VB that deviates from this by implementing "natural alignment" techiques.

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>