Visual Basic, Passing and retriving of strings from VB 6 to Fortran 90

Passing and retriving of strings from VB 6 to Fortran 90

Author	Message
xyz #1 / 6	Passing and retriving of strings from VB 6 to Fortran 90 Hello, Newbie here and I need your help. I am trying to pass some strings from VB 6.0 to a fortran 90 program and then retrive the results (string) from Fortran 90 into VB 6.0 Anyone has any idea how this can be done. Thanks very much for pointing me in the right direction Chin
Fri, 02 Dec 2005 12:14:11 GMT

Duane Bozart #2 / 6	Passing and retriving of strings from VB 6 to Fortran 90 Quote: > Hello, > Newbie here and I need your help. > I am trying to pass some strings from VB 6.0 to a Fortran 90 program and > then retrive the results (string) from Fortran 90 into VB 6.0 > Anyone has any idea how this can be done. > Thanks very much for pointing me in the right direction What compiler? CVF has good mixed-language programming section and samples... try http://h18009.www1.hp.com/fortran/docs/vf-html/vf_frame.htm
Fri, 02 Dec 2005 21:44:26 GMT

Duane Bozart #3 / 6	Passing and retriving of strings from VB 6 to Fortran 90 Quote: > > Hello, > > Newbie here and I need your help. > > I am trying to pass some strings from VB 6.0 to a Fortran 90 program and > > then retrive the results (string) from Fortran 90 into VB 6.0 > > Anyone has any idea how this can be done. > > Thanks very much for pointing me in the right direction > What compiler? CVF has good mixed-language programming section and > samples... > try > http://h18009.www1.hp.com/fortran/docs/vf-html/vf_frame.htm Sorry, I intended to paste the following snippet from there, too, although I'd recommend strongly reading the section as VB has special requirements for strings and arrays in particular... Visual Basic strings must be passed by value to Fortran. Visual Basic strings are actually stored as structures containing length and location information. Passing by value dereferences the structure and passes just the string location, as Fortran expects. For example: ! In Basic Declare Sub forstr Lib "forstr.dll" (ByVal Bstring as String) DIM bstring As String * 40 Fixed-length string CALL forstr(bstring) ! End Basic code ! In Fortran SUBROUTINE forstr(s) !DEC$ ATTRIBUTES STDCALL :: forstr !DEC$ ATTRIBUTES REFERENCE :: s CHARACTER(40) s s = 'Hello, Visual Basic!' END Obviously the Fortran side will be compiler-specific to incorporate the equivalence of the STDCALL and REFERENCE directives of CVF...
Fri, 02 Dec 2005 21:55:14 GMT

Dan Te #4 / 6	Passing and retriving of strings from VB 6 to Fortran 90 Quote: >> > Hello, >> > Newbie here and I need your help. >> > I am trying to pass some strings from VB 6.0 to a Fortran 90 program >and >> > then retrive the results (string) from Fortran 90 into VB 6.0 >> > Anyone has any idea how this can be done. >> > Thanks very much for pointing me in the right direction >> What compiler? CVF has good mixed-language programming section and >> samples... >> try >> http://h18009.www1.hp.com/fortran/docs/vf-html/vf_frame.htm >Sorry, I intended to paste the following snippet from there, too, >although I'd recommend strongly reading the section as VB has special >requirements for strings and arrays in particular... >Visual Basic strings must be passed by value to Fortran. Visual Basic >strings are actually stored as structures containing length and location >information. Passing by value dereferences the structure and passes just >the string location, as Fortran expects. >For example: > ! In Basic > Declare Sub forstr Lib "forstr.dll" (ByVal Bstring as String) > DIM bstring As String * 40 Fixed-length string > CALL forstr(bstring) > ! End Basic code > ! In Fortran > SUBROUTINE forstr(s) > !DEC$ ATTRIBUTES STDCALL :: forstr > !DEC$ ATTRIBUTES REFERENCE :: s > CHARACTER(40) s > s = 'Hello, Visual Basic!' > END >Obviously the Fortran side will be compiler-specific to incorporate the >equivalence of the STDCALL and REFERENCE directives of CVF... Just a side thought here.... If you intend to use your code well into the future... or rather... to recompile your fortran code in the future... you "might" give some consideration to writing your string data to an intermediate disk file and have the "other" program read it from there. This method has the distinct advantage of more portability over the long haul. As Duane pointed out... his solution is specific to the DVF Fortran compiler and is not guaranteed with any other compiler ( including later versions of the DVF ( now Intel ) compiler ). The actual passing mechanism which a fortran compiler implements is specific to the compiler. If you make an assumption such as "pass by reference" or "pass by value" and things work ok, just be clear that you can't necessarily depend on that behavior. Dan :-)
Sat, 03 Dec 2005 08:53:37 GMT

Craig Power #5 / 6	Passing and retriving of strings from VB 6 to Fortran 90 Quote: > Just a side thought here.... > If you intend to use your code well into the future... or rather... to > recompile your fortran code in the future... you "might" give some > consideration to writing your string data to an intermediate disk file and have > the "other" program read it from there. This method has the distinct advantage > of more portability over the long haul. As Duane pointed out... his solution > is specific to the DVF Fortran compiler and is not guaranteed with any other > compiler ( including later versions of the DVF ( now Intel ) compiler ). > The actual passing mechanism which a fortran compiler implements is specific to > the compiler. If you make an assumption such as "pass by reference" or "pass > by value" and things work ok, just be clear that you can't necessarily depend > on that behavior. Also consider, though, that similar facilities are necessary for interop with Windows. It's not guaranteed to be portable going forward, but IMO it's unlikely to go away. (It's not, however, as likely to be portable to another platform.)
Sat, 03 Dec 2005 22:24:45 GMT

Duane Bozart #6 / 6	Passing and retriving of strings from VB 6 to Fortran 90 Quote: > > Just a side thought here.... > > If you intend to use your code well into the future... or rather... to > > recompile your fortran code in the future... you "might" give some > > consideration to writing your string data to an intermediate disk file and have > > the "other" program read it from there. This method has the distinct advantage > > of more portability over the long haul. As Duane pointed out... his solution > > is specific to the DVF Fortran compiler and is not guaranteed with any other > > compiler ( including later versions of the DVF ( now Intel ) compiler ). > > The actual passing mechanism which a fortran compiler implements is specific to > > the compiler. If you make an assumption such as "pass by reference" or "pass > > by value" and things work ok, just be clear that you can't necessarily depend > > on that behavior. > Also consider, though, that similar facilities are necessary for > interop with Windows. It's not guaranteed to be portable going > forward, but IMO it's unlikely to go away. (It's not, however, as > likely to be portable to another platform.) Of course, as I was going to point out to Dan, if you're talking about mixed language programming w/VB, you're pretty much saying you don't give a hoot about portability anyway!! :) And, as far as the "going forward" bit, MS has already killed that w/.NET as VB5/6 have already been relegated to the trashbin and the .NET incarnation is not at all the same language as VB.
Sat, 03 Dec 2005 22:58:00 GMT

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