使用GetEnumName和GetEnumValue获取枚举类型的名称和数值

在窗体上添加两个按钮，简单代码如下。GetEnumValue（）超范围时返回-1.

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls,TypInfo;
type
  TTestEnum=(teOne,teTwo,teThree);
  TForm1 = class(TForm)
    btn1: TButton;
    btn2: TButton;
    procedure btn1Click(Sender: TObject);
    procedure btn2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.btn1Click(Sender: TObject);
var
  pt: PTypeInfo;
begin
  pt:=TypeInfo(TTestEnum);
  Caption:=GetEnumName(pt,Ord(teTwo));
end;

procedure TForm1.btn2Click(Sender: TObject);
var
  pt: PTypeInfo;
begin
  pt:=TypeInfo(TTestEnum);
  Caption:=IntToStr(GetEnumValue(pt,'teTwo'));
end;

end.