类的继承

当子类继承父类时，就享有了父类的方法，当然有些虚方法，或虚类我将在以后学习

在下面这个例子中，简单讲解一下类的继承

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    btn1: TButton;
    procedure btn1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

  TMyClass1 = class
  private
    { private declarations }
  protected
    { protected declarations }
  public
    procedure Pro1;
    { public declarations }

  published
    { published declarations }
  end;

  TMyClass2 = class(TMyClass1)
  private
    { private declarations }
  protected
    { protected declarations }
  public
    procedure Pro2;
    { public declarations }

  published
    { published declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
{ TMyClass1 }

procedure TMyClass1.Pro1;
begin
  ShowMessage('你好，欢迎光临我的博客');
end;

{ TMyClass2 }

procedure TMyClass2.Pro2;
begin
  ShowMessage('希望我们能够一起进步');
end;

procedure TForm1.btn1Click(Sender: TObject);
var
  MyCla: TMyClass2;
begin
  MyCla := TMyClass2.Create;
  MyCla.Pro1;
  MyCla.Pro2;
end;

end.

在上面这个例子中，MyCla是TMyClass2的实例，当然这里可以不用创建，这需要了解delphi中友元类的概念

在这里我们按照常规方法去做

由于MyCla继承于TMyClass1，所有即由TMyClass1的方法，也有自己的方法