"Invalid Function" with CallFn() from FoxTools

ID: Q101291

2.50 3.00 WINDOWS

The information in this article applies to:

Microsoft Visual FoxPro for Windows, version 3.0
Microsoft FoxPro for Windows, version 2.5

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 reference words: VFoxWin 3.00 FoxWin 2.50 FOXTOOLS Callfn error KBCategory: KBSubcategory: FxprgFoxtools

Keywords          : kberrmsg FxprgFoxtools 
Version           : 2.50 3.00
Platform          : WINDOWS