帮我解释以下关于‘gdfocused in state’的问题吧！

Question

procedure TForm1.StringGrid1DrawCell(Sender: TObject; ACol, ARow: Integer;
  Rect: TRect; State: TGridDrawState);
begin
if (gdfocused in state) or (gdselected in state) or (gdfixed in state) then
   button2.Top:=rect.Top+ StringGrid1.top + 1;
end;
其中if 的作用。

Answer 1

Grid型控件的选项，决定Cell接不接收焦点

Answer 2

判断状态state中是否包含值gdfocused,

Answer 3

gdSelected The cell is currently selected.
gdFocused          The cell has input focus.
gdFixed          The cell is in the fixed region of the grid.