学习官方示例 - System.TClass

本例效果图:

---

代码文件:

---

unit Unit1;

interface

uses
  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}

{获取 Button1 的父类}
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;

{获取 ListBox1 的父类}
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;

{获取当前 Form 的父类}
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.

窗体文件:

---

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
  end
end