GBeckman@... wrote:
> I would like to add to Mike's questions as I share much of his perplexity
> about vrefnums.
> 
> 6.  How can I resolve an alias  (PGs useAlias) and then find out what the
> vrefNum of the new file (in my case often on a server) is?  UseAlias and the
> tool box call resolve alias appear as if they are going to give you refnum,
> but it ain't so.

This is a common source of confusion: UseAlias returns an "fsSpec"
record containing 3 fields which are called "vRefNum", "parID" and
"name".  The "vRefNum" that is in an fsSpec record _is_ in fact a true
volume reference number (like -1, -2, etc.), but the thing that's
usually called "vRefNum" in FB documentation is _not_ a true volume
reference number; it's a "working directory reference number," which is
another thing altogether.

>I want to use it in Andy's example on the STAZ site:
> 
> CLEAR LOCAL MODE
> DIM pBlock.128
> DIM Noerr&
> LOCAL FN SetFilesFolder(Vref%)
>   pBlock.ioVRefNum% = Vref%
> 
>   LONG IF FN GETCATINFO(@pBlock) = _NoErr
>     & _CurDirStore , pBlock.ioDirID&
>     pBlock.ioWDProcID&  = 0
>     pBlock.ioWDVRefNum% = 0
>     LONG IF FN GETWDINFO(@pBlock) = _NoErr
>       % _SFSaveDisk , -pBlock.ioWDVRefNum%
>     END IF
>     NoErr&=FN FLUSHVOL(@pBlock)
>   END IF
> END FN
> 
>         The above fn allows my users to use the finder  (or an alias on the
> desktop) to log onto a server, open a file and have the next open (or save of
> a new document) from within my app. be set to the folder in which the file
> just opened resides.   Trouble is, use alias gives -1, -2, etc. and those are
> not the actual volRefNum.

Actually, UseAlias is saving you a step, so it's unnecessary even to use
FN SetFilesFolder as written.  FN SetFilesFolder expects a working
directory reference number (Vref%), which it then resolves into a (true)
volume reference number and directory ID number, which it then uses to
set globals CurDirStore and SFSaveDisk.  But UseAlias _already_ gives
you the (true) volume reference number and directory ID you need,
because they're part of the returned fsSpec record.  All you should need
to do is this:

DIM RECORD fsSpec
  DIM fsVRefNum%
  DIM fsParID&
  DIM 63 fsName$
DIM END RECORD .fsSpec
:
DIM myFSSpec.fsSpec
:
OSErr = FN UseAlias(resID, @myFSSpec)
% _SFSaveDisk , -myFSSpec.fsVRefNum%
& _CurDirStore,  myFSSpec.fsParID&

Hope this helps.
- Rick