Microsoft KB Archive/121457

= Using Microsoft FORTRAN 5.1 with Visual Basic =

Article ID: 121457

Article Last Modified on 8/31/2005

-

APPLIES TO


 * Microsoft FORTRAN Compiler 5.1
 * Microsoft Visual Basic 3.0 Professional Edition

-



This article was previously published under Q121457



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
The following file is available for download from the Microsoft Download Center:

hf1047.exe

For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:

119591 How to Obtain Microsoft Support Files from Online Services

Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file. 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/

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

---
 * INFORMATION PROVIDED IN THIS DOCUMENT AND ANY SOFTWARE THAT MAY    |
 * 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   |
 * the use of this Application Note. This Application Note may be     |
 * 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)     |
 * must be copied without modification (the MS-DOS(R) utility         |
 * 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.                   |
 * 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 ---

1. 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

2. Install Visual Basic version 3.0.

3. Read chapters 1 and 2 of the "Visual Basic Programmers Guide," and do  the "Hello World" example.

Procedure -

1. Start Visual Basic, and begin a new project.

2. Add the following items to the Form by dragging them from the Tool Box to the Form:

- Four command buttons - One text box

3. 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      |    |                           | |   |
 * |     Test String      |    |                           | |   |
 * |  Test String Array   |    |                           | |   |
 * |     Test Square      |    |                           | |   |
 * |  Test String Array   |    |                           | |   |
 * |     Test Square      |    |                           | |   |
 * |  Test String Array   |    |                           | |   |
 * |     Test Square      |    |                           | |   |
 * |     Test Square      |    |                           | |   |
 * |     Test Square      |    |                           | |   |

4. From the Project Window, select View Code for the Form.

5. 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

6. 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.

7. 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.

8. 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

9. 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

10. 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

11. 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.

12. Run the Visual Basic application, and click the command buttons to   execute the FORTRAN subroutines. The results will appear in the text window.

Additional query words: HF1047.EXE kbfile

Keywords: kbdownload kbfile KB121457

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.