在Delphi中导出对象的正确方法是什么？

Question

我正在考虑以下事项：

library LinuxRPM;

{ Important note about DLL memory management: ShareMem must be the
  first unit in your library's USES clause AND your project's (select
  Project-View Source) USES clause if your DLL exports any procedures or
  functions that pass strings as parameters or function results. This
  applies to all strings passed to and from your DLL--even those that
  are nested in records and classes. ShareMem is the interface unit to
  the BORLNDMM.DLL shared memory manager, which must be deployed along
  with your DLL. To avoid using BORLNDMM.DLL, pass string information
  using PChar or ShortString parameters. }

uses
  System.SysUtils,
  System.Classes;

{$R *.res}

type
  TRadioTracer = class

  end;

var
  RPM: TRadioTracer;

exports
  RPM;

begin
  RPM = TRadioTracer.Create;
end.

但是，不知道我在哪里以及是否需要调用RPM.Free。