rtti读取和设置属性

http://www.cnblogs.com/hnxxcxg/archive/2013/03/02/2940565.html

rtti读取和设置属性

 

编辑器通过 Rtti 还能够调用一个类的方法, 也能读取或设置其属性值. -------------------------------------------------------------------------------- unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm1 = class(TForm) Button1: TButton; Button2: TButton; procedure Button1Click(Sender: TObject); procedure Button2Click(Sender: TObject); end; {自定义的类} TMyClass = class(TComponent) public procedure msg(const str: string); function Add(const a,b: Integer): Integer; end; var Form1: TForm1; implementation {$R *.dfm} uses Rtti; { MyClass 类的实现 -----------------------------------------------------------} procedure TMyClass.msg(const str: string); begin MessageDlg(str, mtInformation, [mbYes], 0); end; function TMyClass.Add(const a, b: Integer): Integer; begin Result := a + b; end; //通过 Rtti 的手段使用 TMyClass 类的方法 -------------------------------------- procedure TForm1.Button1Click(Sender: TObject); var obj: TMyClass; t: TRttiType; m1,m2: TRttiMethod; r: TValue; //TRttiMethod.Invoke 的返回类型 begin t := TRttiContext.Create.GetType(TMyClass); {获取 TMyClass 类的两个方法} m1 := t.GetMethod('msg'); {procedure} m2 := t.GetMethod('Add'); {function} obj := TMyClass.Create(Self); {调用需要依赖一个已存在的对象} {调用 msg 过程} m1.Invoke(obj, ['Delphi 2010']); {将弹出信息框} {调用 Add 函数} r := m2.Invoke(obj, [1, 2]); {其返回值是个 TValue 类型的结构} ShowMessage(IntToStr(r.AsInteger)); {3} obj.Free; end; //通过 Rtti 的手段修改并获取 TMyClass 类的属性 -------------------------------- procedure TForm1.Button2Click(Sender: TObject); var obj: TMyClass; t: TRttiType; p: TRttiProperty; r: TValue; begin obj := TMyClass.Create(Self); t := TRttiContext.Create.GetType(TMyClass); p := t.GetProperty('Name'); p.SetValue(obj, 'NewName'); r := p.GetValue(obj); ShowMessage(r.AsString); {NewName} obj.Free; end; end. -------------------------------------------------------------------------------- 回复下面的问题：如何设置枚举值： -------------------------------------------------------------------------------- procedure TForm1.Button3Click(Sender: TObject); var t: TRttiType; p: TRttiProperty; r: TValue; begin t := TRttiContext.Create.GetType(TButton); p := t.GetProperty('Align'); p.SetValue(Button1, TValue.FromOrdinal(TypeInfo(TAlign), Ord(alLeft))); r := p.GetValue(Button1); ShowMessage(IntToStr(r.AsOrdinal)); {3} end; 加载中...

 

分类: delphi新语法