Delphi 2010 新增功能之: Rtti 单元(3): TRttiOrdinalType

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;

type
TForm1 = class(TForm)
Memo1: TMemo;
Button1: TButton;
procedure Button1Click(Sender: TObject);
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

uses Rtti;

procedure TForm1.Button1Click(Sender: TObject);
var
t: TRttiOrdinalType;
begin
Memo1.Clear;

//先从类型名获取类型信息对象
t := TRttiContext.Create.GetType(TypeInfo(Byte)) as TRttiOrdinalType;
Memo1.Lines.Add(Format('%s - %s', [t.Name, t.QualifiedName]));
Memo1.Lines.Add(Format('Size: %d', [t.TypeSize]));
Memo1.Lines.Add('QualifiedName: ' + t.QualifiedName);
Memo1.Lines.Add(Format('Min,Max: %d , %d', [t.MinValue, t.MaxValue]));
Memo1.Lines.Add(EmptyStr); //空字串

//可以用 AsOrdinal 方法代替前面的 as TRttiOrdinalType
t := TRttiContext.Create.GetType(TypeInfo(Word)).AsOrdinal;
Memo1.Lines.Add(Format('%s: %s', [t.Name, t.QualifiedName]));
Memo1.Lines.Add(Format('Size: %d', [t.TypeSize]));
Memo1.Lines.Add(Format('Min,Max: %d , %d', [t.MinValue, t.MaxValue]));
Memo1.Lines.Add(EmptyStr);

//也可以直接强制转换
t := TRttiOrdinalType(TRttiContext.Create.GetType(TypeInfo(Integer)));
Memo1.Lines.Add(Format('%s: %s', [t.Name, t.QualifiedName]));
Memo1.Lines.Add(Format('Size: %d', [t.TypeSize]));
Memo1.Lines.Add(Format('Min,Max: %d , %d', [t.MinValue, t.MaxValue]));
Memo1.Lines.Add(EmptyStr);
end;

end.