Re: Win AP question

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From: Einar Høst (_ebuffer__at_hotmail.com)
Date: 04/16/04 

Date: Fri, 16 Apr 2004 10:17:45 +0200

I have a follow-up question:

What to do when the type of struct depends on some other input parameter?
Specifically, I need to call a Win32 API function called GetTapeParameters.

I written this:

[DllImport("kernel32"), SetLastError=true]
static extern int GetTapeParameters(
  IntPtr hTape,
  int dwOperation,
  ??? lpTapeInformation
)

The problem is that lpTapeInformation should point to different kinds of
structs depending on the value for dwOperation (dwOperation
GET_TAPE_MEDIA_INFORMATION implies a TAPE_GET_MEDIA_PARAMETERS struct,
whereas dwOperation GET_TAPE_DRIVE_INFORMATION implies a
TAPE_GET_DRIVE_PARAMETERS struct). Therefore, I can't simply put ref
<struct-type> lpTapeInformation...

Any help would be much appreciated!

- Einar

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