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5.10 | 3.00
MS-DOS | WINDOWS
kbinterop kbfile kbappnote kbprg
The information in this article applies to:
- Microsoft FORTRAN optimizing compiler for MS-DOS, version 5.1
- Microsoft Visual Basic for Windows, version 3.0
SUMMARY
This article contains the complete text of Application Note number HF1047.
The title of this Application Note is "HF1047: Using FORTRAN 5.1 with
Visual Basic."
HF1047 describes how to call FORTRAN routines in a .DLL from a Visual Basic
for Windows-based application, and how to create the .DLL file from FORTRAN
code.
MORE INFORMATION
To obtain this Application Note, download HF1047.EXE, a self-extracting
file, from the Microsoft Software Library (MSL) on the following services:
Or you can have this Application Note faxed or mailed to you by calling
Microsoft Product Support Services Monday through Friday, 6:00 A.M. to 6:00
P.M. Pacific time. If you are outside the United States, contact the
Microsoft subsidiary for your area. To locate your subsidiary, go to the
Microsoft Web site http://www.microsoft.com/worldwide/default.htm
THE TEXT OF HF1047
Microsoft(R) Product Support Services Application Note (Text File)
HF1047: USING FORTRAN 5.1 WITH VISUAL BASIC(R)
Revision Date: 9/94
No Disk Included
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| ACCOMPANY THIS DOCUMENT (collectively referred to as an Application |
| Note) IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER |
| EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED |
| WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR |
| PURPOSE. The user assumes the entire risk as to the accuracy and |
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| copied and distributed subject to the following conditions: 1) All |
| text must be copied without modification and all pages must be |
| included; 2) If software is included, all files on the disk(s) |
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| diskcopy is appropriate for this purpose); 3) All components of |
| this Application Note must be distributed together; and 4) This |
| Application Note may not be distributed for profit. |
| |
| Copyright (C) 1994 Microsoft Corporation. All Rights Reserved. |
| Visual Basic, Microsoft, and MS-DOS are registered trademarks and |
| Windows is a trademark of Microsoft Corporation. |
|---------------------------------------------------------------------|
FORTRAN AND VISUAL BASIC FOR WINDOWS(TM)
There are several points to consider when using FORTRAN from Visual
Basic:
- Calling FORTRAN routines from Visual Basic for Windows requires
that the FORTRAN routines be made into a DLL.
- When passing data:
- Both FORTRAN and Visual Basic pass data by reference.
- Visual Basic strings are different from FORTRAN strings. They
include a string structure, and require a special declaration
("ByVal") to force Visual Basic to pass the string pointer.
- In Visual Basic, array indices start at 0. In FORTRAN, they
start at 1.
- There must be a declaration statement in Visual Basic for each
FORTRAN routine that will be called.
- FORTRAN DLLs have two significant problems in file I/O:
- Unformatted or Binary files can't be accessed with FORTRAN
commands.
- ASCII files that are opened in FORTRAN will not be readable
until you exit from Visual Basic.
The solution to both problems is to use Windows API calls to do
file I/O.
NOTE: For additional information on file I/O, please see the
following article in the Microsoft Knowledge Base:
ARTICLE-ID: Q102698
TITLE: Performing File I/O from a FORTRAN Dynamic-Link Library
CREATING A FORTRAN DLL CALLED FROM A VISUAL BASIC PROGRAM
This lab presents the steps required to build a FORTRAN DLL and shows how
to create a Visual Basic application that uses this DLL. This lab also
shows the syntax required to pass various types of data between FORTRAN and
Visual Basic.
Preparation
- Install FORTRAN version 5.1 to target 'MS-DOS and Windows' and
include the Windows DLL library. When this is completed
successfully, the files \FORTRAN\BINB\FL.DEF and
\FORTRAN\LIB\LDLLFEW.LIB will be on your computer
NOTE: If there are problems with any of this, please use the
additional information provided in the following article in the
Microsoft Knowledge Base:
ARTICLE-ID: Q112006
TITLE: FORTRAN 5.1 Setup Procedure for Typical Installations
- Install Visual Basic version 3.0.
- Read chapters 1 and 2 of the "Visual Basic Programmers Guide," and do
the "Hello World" example.
Procedure
- Start Visual Basic, and begin a new project.
- Add the following items to the Form by dragging them from the Tool
Box to the Form:
- Four command buttons
- One text box
- In the Properties Window, modify the properties of the following items:
Object Properties Setting
----------------------------------------------------
Form Caption VB/Fortran Lab
Text Box Text empty
Multi Line True
Scroll Bars 3 Both
Command Button 1 Caption Test Array
Command Button 2 Caption Test String
Command Button 3 Caption Test String Array
Command Button 4 Caption Test Square
At this point, the Form should look something like this:
| VB/Fortran Lab |
| |
| ------------------------------- |
| ------------------------- | | | |
| | Test Array | | | | |
| ------------------------- | | | |
| ------------------------- | | | |
| | Test String | | | | |
| ------------------------- | | | |
| ------------------------- | | | |
| | Test String Array | | | | |
| ------------------------- | | | |
| ------------------------- | | | |
| | Test Square | | | | |
| ------------------------- | | | |
| | | | |
| |---------------------------| | |
| ------------------------------- |
- From the Project Window, select View Code for the Form.
- Add the Visual Basic code as follows:
Add the following code to the Command1 Click event:
Sub Command1_Click ()
Static arr(1 To 3, 1 To 7) As Single
Call ARRAYTEST(arr(1, 1))
For i% = 1 To 3
For j% = 1 To 7
' Enter the following two lines as one, single line of code:
text1.Text = Str$(arr(i%, j%)) + Chr$(13) + Chr$(10)
+ text1.Text
Next j%
Next i%
End Sub
Add the following code to the Command2 Click event:
Sub Command2_Click ()
Dim temp As String * 40
Call STRINGER(temp)
text1.Text = temp + Chr$(13) + Chr$(10) + text1.Text
End Sub
Add the following code to the Command3 Click event:
Sub Command3_Click ()
Static testarray(1 To 5) As StringArray
Call ARRAYSTRING(testarray(1))
For i% = 1 To 5
' Enter the following two lines as one, single line of code:
text1.Text = testarray(i%).strings + Chr$(13) +
Chr$(10) + text1.Text
Next i%
End Sub
Add the following code to the Command4 Click event:
Sub Command4_Click ()
Dim a As Single
a = 4.2
Call Square(a)
text1.Text = Str$(a) + Chr$(13) + Chr$(10) + text1.Text
End Sub
- Create the files for the form by choosing Save Project As from
the file menu. In a directory of your choice, save the form as
VB-FORT.FRM, and save the project as VB-FORT.MAK. Create a new module,
and save it as GLOBAL.BAS.
- From the Project Window, select View Code for GLOBAL.BAS. Add all of
the following code to general declarations section in GLOBAL.BAS:
Type StringArray
strings As String * 24
End Type
Declare Sub ARRAYTEST Lib "fortvb.dll" (Myarray As Single)
Declare Sub STRINGER Lib "fortvb.dll" (ByVal mystring As String)
Declare Sub ARRAYSTRING Lib "fortvb.dll" (Myarray As StringArray)
Declare Sub Square Lib "fortvb.dll" (a As Single)
NOTE: The DLL name in these declarations could include full path to
the FORTRAN DLL (For example, "C:\VB\TEXT\FORTVB.DLL"). Then Visual
Basic won't have to search for it.
- Create the FORTRAN file to be made into a DLL as follows:
Create a file (FORTVB.FOR) with the following contents, and place it
in the same directory where the Form and other Visual Basic files
are located:
C Code for the FORTRAN DLL 'FORTVB.DLL'
subroutine arraystring(arr)
character*24 arr(5)
arr = 'This is a string also'
end
subroutine arraytest(arr)
real*4 arr(3,7)
integer i,j
do i=1,3
do j=1,7
arr(i,j) = 11*i+j-1*i
end do
end do
end
subroutine square(a)
real*4 a
a = a*a
end
subroutine stringer(s)
character*40 s
s = 'This is from fortran'
end
- Create the Definitions file as follows:
Create the file FORTVB.DEF with the following contents:
LIBRARY FORTVB
EXETYPE WINDOWS
PROTMODE
CODE PRELOAD MOVEABLE DISCARDABLE
DATA PRELOAD MOVEABLE SINGLE
HEAPSIZE 1024
EXPORTS WEP
ARRAYTEST
ARRAYSTRING
SQUARE
STRINGER
- Build the DLL by typing the following commands at the MS-DOS prompt
in the directory where the Form and other Visual Basic files
are located:
FL /c /Gw /Aw /G2 FORTVB.FOR
LINK FORTVB,FORTVB.DLL,NUL,/NOD LDLLFEW,FORTVB.DEF
- Copy the DLL to a directory where Visual Basic can find it if the
declarations did not include the full path to the DLL. This could
be either the working directory, C:\WINDOWS\SYSTEM, or a directory
in the path.
NOTE: loading a Visual Basic project does not change the working
directory. The current project directory is not usually searched
when loading a DLL.
- Run the Visual Basic application, and click the command buttons to
execute the FORTRAN subroutines. The results will appear in the
text window.
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