I'm trying to implement calls to an existing C-based DLL within a C# program.  It sounds straightforward enough, but any calls to the extern functions produce a NullReferenceException.

My code looks like this:

[DllImport( @"e:\jbhexe\sscam.dll", EntryPoint="BAM_calcs" )]
public static extern int bamCalcs( long settlementDate,
  ref bamDescr descr, long calcToWhich, ref bamResults results,
  long precisionFlag, long checkInput, ref long status,
  ref byte[] statusText );

and the exception is thrown on the call:

bamCalcs( settlementDate, ref descr, calcToWhich, ref results,
precisionFlag, checkInput, ref status, ref statusText );

I'm guessing that I have to create an instance using Type.GetType(), but since the dll is C-based, I can't figure out what parameters to pass.

If someone has insight into this, your response would be appreciated.

Please contact me at danmehlman@hotmail.com.

Thank you.