Problems calling external functions using PB12 and Windows 7
Posted on 2010-08-25
We have a PowerBuilder 12 application that is crashing when calling an external function under Windows 7. The same application has earlier worked without problem under XP.
The call to the external function seems to work OK since a message box produced by the function displays, but the application then crashes when the user clicks OK to continue (the external function calculates the are of a block in the North sea).
The question is where does the failure occur - in the function itself (in which case it's not my problem) or when returning the calculated area to PB?
The function declaration is:
SUBROUTINE CalcArea(Long n, Long y, Long x, REF Double ar, REF Long ist) library 'GEODETIC.DLL' ALIAS FOR "_dllarea@20;Ansi"
where n is the number of co-ordinates, y & x are the y & x co-ordinates of the block for which the area is to be calculated, ar is the area returned to PB & ist is the return code, also returned to PB.
I suspect that the problem lies with the last two reference parameters, but is there anyone who has experienced (& hopefully solved) a similar problem?
Note that I've tried running the executable on Windows 7 with the /pbdebug switch but this for some reason failed to produce a trace log.