I want to move some data records across a marshalled Ole automation boundry
as efficiently as possible:

record data:

var Resource, location:string15;
     ID:String2;
    Booking_ID:longint;
    duration,start:integer;
    tag:string1;

I want to put a bunch of these records into

var transfer_Array:variant;

transfer_Array:=vararrayCreate([0,length],varbyte);

I'm not sure of how to move the bytes that make up the fields in the records
into the transfer_array, and then on the receiving end to move them from the
array back into a set of similar record variables.

Could someone advise or point me towards some good examples of this in the
doc.
--
Thanks in advance for any help.
Sam...@bookitall.com

On Wed, 27 May 1998 06:22:26 -0400, "Samuel Washburn"

I had a similar problem not so long ago. I couldn't find much
documentation on it either, but eventually (very eventually!) came up
with two *very* useful functions:

{*****************************************************}
function BytesToVariant(pBase: Pointer; iSize: LongInt): OleVariant;
type
  pPointer = ^Pointer;
var
  pDataOut: pPointer;
begin
  Result := VarArrayCreate([0, iSize], VarByte);
  pDataOut := VarArrayLock(Result);
  Move(pBase^, pDataOut^, iSize);
  VarArrayUnlock(Result);
end;

{*****************************************************}
procedure VariantToBytes(aVarArray: OleVariant; pBase: Pointer);
var
 DataIn: Pointer;
begin
  DataIn := VarArrayLock(aVarArray);

  Move(DataIn^, pBase^, VarArrayHighBound(aVarArray, 1));
  VarArrayUnlock(aVarArray);
end;

I've used these functions to pass data between a Client and a Server
on separate machines, e.g. to pass a record from the Server to the
Client, do something like

aOleVar := BytesToVariant(@MyRecord, SizeOf(TMyRecord)

where aOleVar is of type OleVariant. You can these pass the OleVariant
and use the VariantToBytes routine on the Client to reconstruct the
record.

Hope this helps,

John

If you like to pass several  records at a time , maybe you should use a
TClientDataSet and its Data property.
Create a empty AClientdataset (using FieldsDefs), populate it with
records and send send along your interface the AClientDataSet.Data
property.
In the receiver, after retrieving the variant, assign to a
TClientDataSet the received data (AClientDataSet.Data:=ReceivedData)

Remus

For clarification of the above example, could you detail how you declare and
populate "Myrecord" in this example. Again many thanks. Hope I can return
the favor at some point. Sam.

There's a good article on doing something similar to this in a past Delphi
Informant (2 or 3 months ago?), and there's sample code on their website -
see www.informant.com/delphi (or something similar).  The article took a
component from one app and used an Variant array of bytes to pass it to
another app.  Somewhat simpler would be to do this for a record structure.

HTH
Steve Belkin