Delphi 以類別名稱來建立有建構參數的物件

type
  // ...

  TMyParent = class(TComponent)
  public
    function echo(name: string): string; virtual; abstract;
  end;

  TMyParentClass = class of TMyParent;

  TMySub1 = class(TMyParent)
  private
    s: string;
  public
     constructor Create(AOwner: TComponent); override;
     function echo(name: string): string; override;
  end;

  // ...

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
  PClass: TPersistentClass;
  Obj: TMyParent;
begin
  RegisterClass(TMySub1);
  PClass := FindClass('TMySub1');
  Obj := TMyParentClass(PClass).Create(Self);
  Caption := Obj.echo('Solnone');
  UnRegisterClass(TMySub1);
end;

constructor TMySub1.Create(AOwner: TComponent);
begin
  s := AOwner.GetNamePath + ' TMySub1 ';
end;

function TMySub1.echo(name: string): string;
begin
  Result := s+ 'Hello ' + name;
end;

// Form1 TMySub1 Hello Solnone