學習官方樣本 – System.TClass

本例:

代碼檔案:

unit Unit1;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs, StdCtrls;type  TForm1 = class(TForm)    ListBox1: TListBox;    Button1: TButton;    Button2: TButton;    Button3: TButton;    procedure Button1Click(Sender: TObject);    procedure Button2Click(Sender: TObject);    procedure Button3Click(Sender: TObject);  end;var  Form1: TForm1;implementation{$R *.dfm}{擷取 Button1 的父類}procedure TForm1.Button1Click(Sender: TObject);var  ClassRef: TClass;begin  ListBox1.Clear;  ClassRef := Sender.ClassType;  while ClassRef  nil do  begin    ListBox1.Items.Add(ClassRef.ClassName);    ClassRef := ClassRef.ClassParent;  end;end;{擷取 ListBox1 的父類}procedure TForm1.Button2Click(Sender: TObject);var  ClassRef: TClass;begin  ListBox1.Clear;  ClassRef := ListBox1.ClassType;  while ClassRef  nil do  begin    ListBox1.Items.Add(ClassRef.ClassName);    ClassRef := ClassRef.ClassParent;  end;end;{擷取當前 Form 的父類}procedure TForm1.Button3Click(Sender: TObject);var  ClassRef: TClass;begin  ListBox1.Clear;  ClassRef := Self.ClassType;  while ClassRef  nil do  begin    ListBox1.Items.Add(ClassRef.ClassName);    ClassRef := ClassRef.ClassParent;  end;end;end.

表單檔案:

object Form1: TForm1  Left = 0  Top = 0  Caption = 'Form1'  ClientHeight = 147  ClientWidth = 282  Color = clBtnFace  Font.Charset = DEFAULT_CHARSET  Font.Color = clWindowText  Font.Height = -11  Font.Name = 'Tahoma'  Font.Style = []  OldCreateOrder = False  PixelsPerInch = 96  TextHeight = 13  object ListBox1: TListBox    Left = 0    Top = 0    Width = 161    Height = 147    Align = alLeft    ItemHeight = 13    TabOrder = 0    ExplicitHeight = 155  end  object Button1: TButton    Left = 184    Top = 24    Width = 75    Height = 25    Caption = 'Button1'    TabOrder = 1    OnClick = Button1Click  end  object Button2: TButton    Left = 184    Top = 64    Width = 75    Height = 25    Caption = 'Button2'    TabOrder = 2    OnClick = Button2Click  end  object Button3: TButton    Left = 184    Top = 104    Width = 75    Height = 25    Caption = 'Button3'    TabOrder = 3    OnClick = Button3Click  endend