Is Finalize needed in Delphi?

[jeffp]

I'm using Delphi and creating the object

FObj := TPXC_Inst.Create(nil);
FObj.Init(LIC_KEY);

It appears that when done all I need to do is call

FObj.Free;

Your help said to make sure to call

FObj.Finalize;

However, if I do in fact close by doing this

FObj.Finalize;
FObj.Free;

Then I get exceptions if I create another FObj and do things like open files.

So it appears that FObj.Finalize is not needed but just FObj.Free; with Delphi.

Can you confirm this?

Thanks.

--Jeff

[Sasha - PDF-XChange]

Hello jeffp,

Have you tried using Finalize method only without the Free method?

Cheers,
Alex

[jeffp]

I haven't. But that seems to cut against the way objects should be freed in Delphi. That is, if you create and object you should always free it.

I'll give it a try and let you know.

[Sasha - PDF-XChange]

I you're using control multiple times, you must create PXV_Inst ONE time globally and destroy it ONCE after the program end.
As described in this topic:
https://forum.pdf-xchange.com/ ... 125#p98125

Cheers,
Alex

[jeffp]

Ok. I follow, but I don't. Let's start with the simple Delphi example below. The second time I call the GetPageCount example below I get a crash. If I comment out the "Finalize" line, it does not crash on subsequent calls.

Code: Select all

function GetPageCount(AFileName: String): Cardinal;
var
  ADoc: IPXC_Document;
begin
  with TPXC_Inst.Create(nil) do
  try
    Init(LIC_KEY);
    ADoc := OpenDocumentFromFile(PChar(AFileName), nil, nil, 0, 0);
    ADoc.Pages.Get_Count(Result);
    Finalize; //If I comment this line out there are no crashes on subsequent calls.
  finally
    Free;
  end;
end;

I'm trying to write some non-visual procedures that will manipulate some PDF files so I'm not putting any objects on TForms, etc. As such, I'm trying to figure out how these new interfaces work. You talk about creating just one IPXC_Inst interface for the life of the application session. How would that look given I'm using the TPXC_Inst activeX object above. Are you saying just create one Global instance of the TPXC_Inst object? I guess I don't follow exactly what Init and Finalize are doing and how to use them with multiple instances of the TPXC_Inst object.

Any help here would be greatly appreciated as I want to make sure I understand these concepts from the start.

You used to have a resident Delphi expert there, but I forgot his name. Who is that?

Lastly, can you confirm that I'm using the IBitSet properly below.

Code: Select all

procedure TPDF_Core.DeletePages(APagesAsCommaText: String);
var
  i, APage: Integer;
  APageCount: Cardinal;
  BS: IBitSet;
  AOut: IPXC_UndoRedoData;
begin
  if Assigned(FDoc) then
  begin
    FDoc.Pages.Get_Count(APageCount);
    if (APageCount > 1) then
    begin
      BS := FInstAUX.CreateBitSet(APageCount);
      BS.SetSize(APageCount);

      with TStringList.Create do
      try
        CommaText := APagesAsCommaText;
        for i := 0 to Count - 1 do
        begin
          APage := StrToIntDef(Strings[i], 0);
          if (APage >= 1) and (APage <= APageCount) then BS.Item[APage - 1] := True;
        end;
      finally
        Free;
      end;

      FDoc.Pages.DeletePages(BS, nil, AOut);
    end;
  end;
end;

--Jeff

[Sasha - PDF-XChange]

Hello Jeff,

Replied here:
https://forum.pdf-xchange.com/ ... 064#p99064