unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm1 = class(TForm) end; TBass = class function Fun1(x,y: Integer): Integer; virtual; {Fun1 有 virtual 指示字} function Fun2(x,y,z: Integer): Integer; {Fun2 有三个参数、一个返回值} end; var Form1: TForm1; implementation {$R *.dfm} { TBass } function TBass.Fun1(x, y: Integer): Integer; {方法实现时, 不能带 virtual 等指示字} begin Result := x + y; end; function TBass.Fun2(x,y,z: Integer): Integer; {方法实现时可以只有函数名; 如果带参数和返回值, 必须和定义时一样} begin Result := x + y + z; end; end.