方法重载

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs;

type
  TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

//有方法重载的类
  TMyClass = class
  public
    procedure MyProc(i: Integer); overload;
    procedure MyProc(s: string); overload;
    function MyProc(s1,s2: string): string; overload;
  end;
//关于方法重载：
//过程和函数之间可以重载
//类内重载必须有 overload 关键字
//子类重载必须有 overload 关键字，夫类可以没有
//如果夫类是虚函数(virtual dynamic),子类重载时需要加 reintroduce 修饰词
//published 区内不能重载

var
  Form1: TForm1;

implementation

{$R *.dfm}

{ TMyClass }

procedure TMyClass.MyProc(i: Integer);
begin
  ShowMessage(IntToStr(i));
end;

procedure TMyClass.MyProc(s: string);
begin
  ShowMessage(s);
end;

function TMyClass.MyProc(s1, s2: string): string;
begin
  Result := s1 + ' and ' + s2;
end;

//测试
procedure TForm1.FormCreate(Sender: TObject);
var
  class1: TMyClass;
begin
  class1 := TMyClass.Create;

  class1.MyProc(2);  //2
  class1.MyProc('2');  //2
  ShowMessage(class1.MyProc('2','3'));  //2 and 3

  class1.Free;
end;

end.

原文链接：https://www.cnblogs.com/del/archive/2007/12/05/983733.html