Q118814: DOCERR: Win32 APIs Callable from a QuickWin Application

Article: Q118814
Product(s): Microsoft Fortran Compiler
Version(s): 1.0,4.0
Operating System(s): 
Keyword(s): kbFortranPS kbLangFortran
Last Modified: 02-NOV-1999

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The information in this article applies to:

- Microsoft Fortran Powerstation 32 for Windows NT, versions 1.0, 4.0 
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SUMMARY
=======

On page 166 of the PowerStation 32 "Programmer's Guide," the first paragraph
implies that you cannot call Win32 APIs from a QuickWin application; however,
you actually can call Win32 APIs that do not require a window handle.

MORE INFORMATION
================

To call a Win32 API, you must create a proper INTERFACE TO statement and link
with the proper import library.

You can determine the proper INTERFACE TO statement by reading the "Win32
Programmer's Reference". The STDCALL attribute is required for the function
declaration.

The sample code below calls the MessageBox() API, contained in the import
library, USER32.LIB, which is already linked into the program for a QuickWin
application by default. The first parameter of MessageBox() is a window handle
or 0 (NULL). You must use 0, because the window handle is not available in a
QuickWin application.

NOTE: When you pass a string to an API, make sure that you use the C convention,
so that the string is NULL terminated. See page 53 of the "Programmer's Guide"
for a discussion of C strings.

Sample Code
-----------

  C Compile options needed: /MW

        INTERFACE TO FUNCTION
       +MESSAGEBOX  (hwnd, text, title, icon)
        INTEGER*4 MESSAGEBOX [STDCALL, ALIAS:'_MessageBoxA@16']
        INTEGER*4 hwnd [VALUE]
        CHARACTER*(*) text [REFERENCE]
        CHARACTER*(*) title [REFERENCE]
        INTEGER*4 icon [VALUE]
        END

        CHARACTER text*34, title*21

        text = 'This API was called from FORTRAN.'C
        title = 'QuickWin Application'C

        PRINT*, "Enter any character to continue: "
        READ(*, '(A)')

        i = MESSAGEBOX(0, text, title, 1)

        PRINT*, "MessageBox called"

        END

Additional query words: 1.00 4.00 docerr

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Keywords          : kbFortranPS kbLangFortran 
Technology        : kbAudDeveloper kbFortranSearch kbZNotKeyword2 kbFORTRANPower32100NT kbFORTRANPower32400NT
Version           : :1.0,4.0

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