以下是我製作Tutorial時之程式片斷, 提供參考
1. rbBase.pas (宣告Base Class及Class function)
type
  TfmrbBase = class(TForm)
    ...
  public
    class function GetDescpt:string; virtual; abstract;
  end;    2. unit T01.pas(第一個Child)
type
  Tfm01 = class(TfmrbBase)
    ..
  public
    class function GetDescpt:string; override;
    { Public declarations }
  end;    implementation
{$R *.dfm}
class function Tfm01.GetDescpt: string;
begin
  Result:='直接使用ppDataPipeline連接DataSource 之簡單Report';
end;    3. unit T02.pas(第二個Child)
type
  Tfm01 = class(TfmrbBase)
    ..
  public
    class function GetDescpt:string; override;
    { Public declarations }
  end;    implementation
{$R *.dfm}
class function Tfm02.GetDescpt: string;
begin
  Result:='使用ppReport之內部Pipeline連接資料庫';
end;    4. main.pas--FormCreate時先建立List, User選擇時, Show所選CLass之Descpt 
...
uses rbBase,t01,t02;    {$R *.dfm}    procedure TfmMain.FormCreate(Sender: TObject);
begin
  ListBox1.items.AddObject('01 Simple Report',TObject(Tfm01));
  ListBox1.items.AddObject('02 使用內部PipeLine',TObject(Tfm02));
end;    procedure TfmMain.ListBox1Click(Sender: TObject);
var
  id:integer;
  fmclass:TrbClass;
begin
  id:=ListBox1.itemindex;
  if id >=0 then begin
    fmclass := TrbClass(Listbox1.Items.Objects[id]);
    Memo1.lines.clear;
    memo1.lines.add(fmclass.GetDescpt);  //呼叫Class Function取得字串
  end;
end;