RegFn( )

Registers a Windows API function and the arguments that function takes.

Note

• On 16-bit Windows platforms, RegFn( ) calls 16-bit DLLs.
  
  
• On 32-bit Windows platforms, RegFn( ) calls 32-bit DLLs (if you pass the default number of arguments).

  Syntax

  RegFn(cFunctionName, cArgTypes, cReturnType, cDLLName)

  cFunctionName

  Specifies the name or the ordinal value of the function to be registered.

  cArgTypes

  Specifies a string of characters which describe what arguments the function will accept. The following values are allowed:

Each argument type may be preceded by @ to indicate that the argument is passed by reference. The default is to pass arguments by value.

cReturnType

Specifies the return type of the function. The values allowed are the same as given above for the argument except that return by reference isn't allowed.

cDLLName

Specifies the name of the DLL library that contains the function. This is optional if the function is in one of the libraries on the Win16 (User.exe, Krnl386.exe, and Gdi.exe) or Win32 (Kernel32.dll, Gdi32.dll User32.dll, Advapi32.dll, and Mpr.dll) platforms.

See the Windows SDK function LoadLibrary for details on how the DLL name is searched.

Return Type

Numeric

Remarks

If successful, RegFn( ) returns a number which can be used to reference the function in future calls to CallFn( ).

Returns –1 if the library couldn't be opened, and will additionally display a message box.

The same function can be registered more than once. This allows functions that take different arguments to be used by declaring them again with different argument types.