枚举类型如何转换成字符串类型

uses   TypInfo; type   TTest = (clRedX, clGreenX,clBlueX,clBlackX,clWhiteX,clYellowX);    procedure TForm1.Button1Click(Sender: TObject); var   ti: PTypeInfo;   td: PTypeData;   i: Integer; begin   ti := TypeInfo(TTest);   td := GetTypeData(ti);   for i := td^.MinValue to td^.MaxValue do     ListBox1.Items.Add(GetEnumName(ti, i)); end;