🚀 go-pugleaf

Ruediger Spindler wrote in message <349D0C91.9C60FFAB@on-line.de>...
>Hello all vdbase programmers,
>I try to access a TWAIN-compatible scanner from vdbase 5.5, using the
>EXTERNal DLL EZTWAIN 1.06 and 1.07, but getting problems by passing
>the filename to one of it's functions. All other functions are working
>well.
>The code I tried:
>
>***************************************************************************
****
>
>EXTERN CINT TWAIN_AcquireToFilename( CHANDLE, CSTRING ) EZTWAIN.DLL
>EXTERN CINT MessageBox( CHANDLE, CSTRING, CSTRING, CWORD) USER.EXE
>
>      tempfile = "SCANTEMP.BMP"
>      MessageBox( 0, "This file will be created", tempfile, 0 )
>      scanres = TWAIN_AcquireToFilename( 0, tempfile )
>      if scanres > 0                              && (will always fail
>with -2 = illegal filename)
>***************************************************************************
****
>
>Visual dBASE uses:
> - pascal calling convention
> - 16bit DLLs only
> - CHANDLE = 16bit WORD
> - CSTRING = zero terminated char far *
>So everything should be OK...
>
>The problem on this:
>The external Windows DLL-Func "MessageBox" works OK, but the EZTWAIN
>DLL-Func "TWAIN_AcquireToFileName" seems to misunderstand the filename
>and uses garbage-strings (or NULL or empty) instead and so fails to
>create the file...

You might try prototyping the function like this:

 EXTERN CINT TWAIN_AcquireToFilename( CHANDLE, CPTR ) EZTWAIN.DLL

Append a null to the string parameter:

      tempfile = "SCANTEMP.BMP"+chr(0)
      MessageBox( 0, "This file will be created", tempfile, 0 )
      scanres = TWAIN_AcquireToFilename( 0, tempfile )
____
Bowen Moursund
bowenNOSPAM@nerds.com
http://www.mindspring.com/~bowenm/datatech.htm