delphi – 为什么我不能将TObjectList传递给期望TObjectList的函

接口：

type
   TItem = class
end;

type
  IItemsLoader = interface
    procedure LoadAll(AList : TObjectList<TItem>);
end;

type
  TItemsLoader = class(TInterfacedObject,IItemsLoader)
public
  procedure LoadAll(AList : TObjectList<TItem>);
end;

type
  IItems<T : TItem> = interface
  function LoadAll : TObjectList<T>;
end;

type
  TItems<T : TItem> = class(TInterfacedObject,IItems<T>)
  private
    FItemsLoader : TItemsLoader;
  public
    constructor Create;
    destructor Destroy; override;
    function LoadAll : TObjectList<T>;
end;

执行：

procedure TItemsLoader.LoadAll(AList: TObjectList<TItem>);
begin
  /// some stuff with AList
end;

{ TItems<T> }

constructor TItems<T>.Create;
begin
  FItemsLoader := TItemsLoader.Create;
end;

destructor TItems<T>.Destroy;
begin
  FItemsLoader.Free;
  inherited;
end;

function TItems<T>.LoadAll: TObjectList<T>;
begin
  Result := TObjectList<T>.Create();

  /// Error here
  /// FItemsLoader.LoadAll(Result);
end;