PB -> VB Callback error

[Gregery D Engle]

This runs fine but it seems to run my vb code synchronously and
once it makes a callback it will briefly comeback to life and
then lock back up.

'--PB CODE ---'

#COMPILE DLL "c:\windows\system\PSC.dll"
#DIM ALL
%True  = -1
%False = 0

'DECLARE SUB Display(BYVAL sData AS STRING)
DECLARE FUNCTION test() AS LONG
'DECLARE FUNCTION GetPSC(BYVAL Address AS LONG PTR, COMMPORT AS LONG) AS LONG
DECLARE FUNCTION PBMAIN() AS LONG

FUNCTION GetPSC(BYVAL Address AS LONG PTR) EXPORT AS LONG
  'CALL DWORD Address
  DIM hComm   AS LONG
  DIM Echo    AS LONG
  DIM Qty     AS LONG
  DIM Stuf    AS STRING
  DIM MyInput AS STRING
  DIM CommPort AS LONG
  commPort = 1
'
    DIM NewString AS STRING PTR
'    NewString = glCode
    
 DIM Counter AS LONG
'#DEBUG PRINT "COM" & STR$(COMMPORT)
  COMM OPEN "COM" & LTRIM$(STR$(COMMPORT)) AS #hComm
  IF ERRCLEAR THEN EXIT FUNCTION          'Exit if port cannot be opened

  COMM SET #hComm, BAUD     = 9600        '1200 baud
  COMM SET #hComm, BYTE     = 8           '8 bits
  COMM SET #hComm, PARITY   = %False      'No parity
  COMM SET #hComm, STOP     = 0           '1 stop bit
  COMM SET #hComm, TXBUFFER = 1024        '1k transmit buffer
  COMM SET #hComm, RXBUFFER = 1024        '1k receive buffer
 ' counter = 1
 DO
    Qty = COMM(#hComm, RXQUE)

    IF ISTRUE Qty THEN
       COMM RECV #hComm, Qty, Stuf
'       @NewString = Stuf
       OPEN "C:\hook.id" FOR OUTPUT AS #2
       PRINT #2, Stuf
       CLOSE #2
       CALL DWORD Address
    END IF
 LOOP

Terminate:
  COMM CLOSE #hComm                       'close the comm port and exit
  EXIT FUNCTION

END FUNCTION

FUNCTION PBMAIN() AS LONG
DIM a&
    a& = GetPSC(CODEPTR(test))
END FUNCTION

FUNCTION test() AS LONG
    MSGBOX "hi" 'glcode$
END FUNCTION

'---VB CODE ---'

'---- MAIN.BAS ----'
Option Explicit
Public Declare Function GETPSC Lib "PSC.DLL" (ByVal funcptr As Long) As Long

Sub main()
FrmMain.Show
End Sub

Sub TestSub()
MsgBox "blah blah blah yoyo"
End Sub

'---- FRMMAIN.FRM -----'
Private Sub Command1_Click()
GETPSC AddressOf TestSub
End Sub

Thanks,



------------------
-Greg

[Tom Hanlin]

Sounds like it's working the way I'd expect it to work. The question is, how do you expect it to work?

------------------
Tom Hanlin
PowerBASIC Staff

[Gregery D Engle]

Tom,

It seems to stop execution of my VB program when I execute this and
then it returns execution when I call dword.

This program is being used for a barcode scanner.

Thanks,

------------------
-Greg

[Tom Hanlin]

If you want to run the VB code at the same time as the PB code, you
will need to use a different approach-- multithreading, perhaps,
although VB has limited support for that (see the FAQ "forum").

Depending on what you have in mind, you might find it effective
simply to maintain a message pump in your DO..LOOP, which is currently
blocking the flow of messages to your program.

The loop is also going to eat a lot of CPU time doing nothing in
particular. You might want to look into the WaitForSingleObject API
call and related functions.

------------------
Tom Hanlin
PowerBASIC Staff