先作个记录，后面再研究为什么

  TFileServiceFunction = record
  strict private
    type
      TFunctionNameRec = record
        const
          LoadFile = 'LoadFile';
          SaveFile = 'SaveFile';
          GetAllFileNames = 'GetAllFileNames';
      end;

      TFunctionParamRec = record
        const
          LoadFile_ImageName = 'imageName';
          SaveFile_ImageName = 'imageName';
      end;
  public
    const
      Name: TFunctionNameRec = ();  ??必须要有
      Param: TFunctionParamRec = ();  ？？
  end;