控制Excel字体时出错'Method Font' not supported by aut0mation object!(50分)

程序如下:
var
App_Excel, WorkBook, Sheet: OleVariant
begin
App_Excel := CreateOleObject('Excel.Application');
WorkBook := APP_Excel.Workbooks.Add;
WorkBook.WorkSheets[1].Font.Size := 8;
end;
出错信息为:
Error:'Method Font' not supported by aut0mation object.

WorkSheet没有Font属性。
WorkBook.WorkSheets[1].Range['A1:C1'].Font.Size := 8;

接受答案了.