delphi – 如何检查一个类是否实现了一个接口,尊重超集？

type
  IA = interface(IInterface)
  ['{C9C5C992-3F67-48C5-B215-7DCE6A61F0E8}']
  end;

  IB = interface(IA)
  ['{F1799437-AD12-471B-8716-F1D93D1692FC}']
  end;

  IC = interface(IB)
  ['{01780E8C-C47D-468E-8E42-4BFF3F495D51}']
  end;

  TBO = class(TInterfacedObject,IB)
  end;

procedure TForm1.FormCreate(Sender: TObject);
var
  x: TBO;
  a: IInterface;
begin
  x := TBO.Create;
  IInterface(x)._AddRef;

  if Assigned(TBO.GetInterfaceEntry(IA)) then memo1.lines.add('GetInterfaceEntry IA: OK'); // Why not?
  if Assigned(TBO.GetInterfaceEntry(IB)) then memo1.lines.add('GetInterfaceEntry IB: OK');
  if Assigned(TBO.GetInterfaceEntry(IC)) then memo1.lines.add('GetInterfaceEntry IC: OK');

  if x.QueryInterface(IA,a)=S_OK then memo1.lines.add('QueryInterface TA: OK'); // Why not?
  if x.QueryInterface(IB,a)=S_OK then memo1.lines.add('QueryInterface TB: OK');
  if x.QueryInterface(IC,a)=S_OK then memo1.lines.add('QueryInterface TC: OK');

  if Supports(TBO,IA) then memo1.lines.add('Supports TA: OK'); // Why not?
  if Supports(TBO,IB) then memo1.lines.add('Supports TB: OK');
  if Supports(TBO,IC) then memo1.lines.add('Supports TC: OK');

  if Supports(x,IA,a) then memo1.lines.add('Supports(2) TA: OK'); // Why not?
  if Supports(x,IB,a) then memo1.lines.add('Supports(2) TB: OK');
  if Supports(x,IC,a) then memo1.lines.add('Supports(2) TC: OK');
end;

输出：

GetInterfaceEntry IB: OK
QueryInterface TB: OK
Supports TB: OK
Supports(2) TB: OK

但是我需要：

GetInterfaceEntry IA: OK
GetInterfaceEntry IB: OK
QueryInterface TA: OK
QueryInterface TB: OK
Supports TA: OK
Supports TB: OK
Supports(2) TA: OK
Supports(2) TB: OK

据我所知,由于接口继承,IB是IA的超集.据我所知,由于TBO实现IB,它会自动实现IA.但是为什么Supports(),QueryInterface(),GetInterfaceEntry()返回false？

如何直接或间接地,即通过实施IA的超集,如何查询TBO？我需要两者,一个像GetInterfaceEntry这样的静态类函数和一个像QueryInterface这样的动态对象引用变量.