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Q101291: "Invalid Function" with CallFn() from FoxTools

Article: Q101291
Product(s): Microsoft FoxPro
Version(s): WINDOWS:2.5,3.0
Operating System(s): 
Keyword(s): kberrmsg
Last Modified: 05-FEB-2000

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, version 3.0 
- Microsoft FoxPro for Windows, version 2.5 
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SUMMARY
=======

The FOXTOOLS.FLL library is used to call Windows API functions from within
FoxPro. However, FOXTOOLS.FLL cannot call a .DLL that requires more than nine
parameters. If an attempt is made to call a .DLL with more than nine parameters,
FoxPro will return the "Invalid Function, Argument, Type or Count" error
message.

The following example demonstrates this problem. It calls a function named "Beep"
in a .DLL named "Mydll.dll" with ten parameters. When the CallFn() function that
is part of FOXTOOLS.FLL is issued, FoxPro returns the error message described
above:


     SET LIBRARY TO SYS(2004)+"FOXTOOLS.FLL"t!
     test='TEST'
     handle=REGFN("beep", "CCCCCCCCCC", "", "c:\msvc\example\dlls\mydll.dll")
     test=CALLFN(handle,test,test,test,test,test,test,test,test,test,test)
     SET LIBRARY TO


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

The functionality of Microsoft FoxPro for Windows can be enhanced by calling a
Windows .DLL within FoxPro. FoxPro for Windows comes with a FoxPro application
programming interface (API) library that allows FoxPro programs to call Windows
DLL functions that meet the criteria as described in the FOXTOOLS.WRI file in
the FOXPROW\GOODIES\FOXTOOLS directory. A large number of Windows API functions
meet these criteria.

Additional query words: VFoxWin FoxWin 2.50 FOXTOOLS Callfn error

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Keywords          : kberrmsg 
Technology        : kbVFPsearch kbAudDeveloper kbFoxproSearch kbFoxPro250 kbVFP300
Version           : WINDOWS:2.5,3.0

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