04.Delphi通过接口IInterface实现多重继承
作者:互联网
IInterface表示申明了一些函数,自己本身没有实现部分,需要由继承它的类来实现函数
uSayHello代码如下
unit uSayHello; interface uses SysUtils, Windows, Messages, Classes, Graphics, Controls, Forms, Dialogs; type // IInterface表示申明了一些函数,自己本身没有实现部分,需要由继承它的类来实现函数 ISpeakChinese = interface(IInterface) function SayHello: string; end; // IInterface表示申明了一些函数,自己本身没有实现部分,需要由继承它的类来实现函数 ISpeakEnglish = interface(IInterface) function SayHello: string; end; // 人类 TMan = class(TInterfacedObject) private // 姓名 FName: string; public property Name: string read FName write FName; end; // 中国人,继承了人类和说汉语 TChinese = class(TMan, ISpeakChinese) private // ISpeakChinese中定义的函数,序号在继承类中实现 function SayHello: string; end; TAmerican = class(TMan, ISpeakEnglish) private // ISpeakChinese中定义的函数,序号在继承类中实现 function SayHello: string; end; // 美籍华人 ,继承了人类,汉语和英语 TAmericanChinese = class(TMan, ISpeakChinese, ISpeakEnglish) public constructor create; // ISpeakChinese中定义的函数,序号在继承类中实现 function SayHello: string; end; implementation { ********************************** TAmerican *********************************** } function TAmerican.SayHello: string; begin result := 'Hello!'; end; { *********************************** TChinese *********************************** } function TChinese.SayHello: string; begin result := '你好!'; end; { ******************************* TAmericanChinese ******************************* } constructor TAmericanChinese.create; begin name := 'Tom Wang'; end; function TAmericanChinese.SayHello: string; var Dad: ISpeakChinese; Mum: ISpeakEnglish; begin Dad := TChinese.create; Mum := TAmerican.create; // 调用说中文和说英文方法 result := Dad.SayHello + Mum.SayHello; end; end.
界面代码如下
unit frmMain; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, ExtCtrls; type TForm1 = class(TForm) Button1: TButton; LabeledEdit1: TLabeledEdit; procedure Button1Click(Sender: TObject); private { Private declarations } public { Public declarations } end; var Form1: TForm1; implementation uses uSayHello; {$R *.dfm} procedure TForm1.Button1Click(Sender: TObject); var Tom: TAmericanChinese; begin // 创建美籍华人类 Tom := TAmericanChinese.Create; try LabeledEdit1.text := Tom.Name; // 输出 ShowMessage(Tom.sayhello); finally Tom.Free; end; end; end.
标签:function,end,string,04,Delphi,SayHello,IInterface,TAmericanChinese,ISpeakChinese 来源: https://www.cnblogs.com/tianpan2019/p/11473979.html