delphi 事件和属性的绑定

TWindowState = (wsNormal, wsMinimized, wsMaximized);  

TScrollingWinControl = class(TWinControl)
private
  FHorzScrollBar: TControlScrollBar;
  FVertScrollBar: TControlScrollBar;
  FAutoScroll: Boolean;
  FAutoRangeCount: Integer;
  FUpdatingScrollBars: Boolean;
  procedure CalcAutoRange;
  procedure ScaleScrollBars(M, D: Integer);
  procedure SetAutoScroll(Value: Boolean);
  procedure SetHorzScrollBar(Value: TControlScrollBar);
  procedure SetVertScrollBar(Value: TControlScrollBar);
  procedure UpdateScrollBars;
  procedure WMSize(var Message: TWMSize); message WM_SIZE;
  procedure WMHScroll(var Message: TWMHScroll); message WM_HSCROLL;
  procedure WMVScroll(var Message: TWMVScroll); message WM_VSCROLL;
  procedure CMBiDiModeChanged(var Message: TMessage); message CM_BIDIMODECHANGED;
protected
  procedure AdjustClientRect(var Rect: TRect); override;
  procedure AlignControls(AControl: TControl; var ARect: TRect); override;
  function AutoScrollEnabled: Boolean; virtual;
  procedure AutoScrollInView(AControl: TControl); virtual;
  procedure ChangeScale(M, D: Integer); override;
  procedure CreateParams(var Params: TCreateParams); override;
  procedure CreateWnd; override;
  procedure DoFlipChildren; override;

//此处所定义的就是 delphi 中object inspector 中的对象属性所显示的内容  TControlScrollBar类型， 读取FHorzScrollBar 通过SetHorzScrollBar写入
 property HorzScrollBar: TControlScrollBar read FHorzScrollBar write SetHorzScrollBar;
  property VertScrollBar: TControlScrollBar read FVertScrollBar write SetVertScrollBar;
end;

上面是系统定义的，比较枯燥，下面是自己写的代码：

unit Unit1;  

interface  

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

type
  TForm1 = class(TForm)
    btn1: TButton;
    edt1: TEdit;
    procedure FormCreate(Sender: TObject);    //窗体创建事件
    procedure btn1Click(Sender: TObject);     //butten 点击事件
  private
  public
    //自己写的过程 显示位置
    procedure OnTestPostionChange(Sender: TObject; Positon: Integer);
  end;  

   // 类似于函数指针 of object 它必须指向某个对象的方法(即成员函数).
  TTestEvent = procedure (Sender: TObject; Positon: Integer) of Object;  

  TTestClass = class(TObject)
  private
    FPosition: Integer;      // Position 属性用的
    FOnPositionChange: TTestEvent; // OnPositionChange 属性
    procedure SetPosition(const Value: Integer);
  protected
    procedure DoPositonChange;
   // procedure doaaa: dynamic;
  public
    //属性 position 读取FPosition 写到SetPosition   integer 类型
    property Position: Integer read FPosition write SetPosition;
    //属性 onPositionChange  对象过程函数指针类型 读取FOnposition  写入 FOnPositionChange
    property OnPositionChange: TTestEvent read FOnPositionChange write FOnPositionChange;
  end;  

var
  Form1: TForm1;
  test1: TTestClass;  

implementation  

{$R *.dfm}  

procedure TForm1.FormCreate(Sender: TObject);
begin
  test1 := TTestClass.Create;
  test1.OnPositionChange := OnTestPostionChange;
end;  

{ TTestClass }  

procedure TTestClass.DoPositonChange;
begin
  if Assigned(FOnPositionChange) then
    FOnPositionChange(Self,FPosition);
end;  

procedure TTestClass.SetPosition(const Value: Integer);
begin
  if Value <> FPosition then
  begin
    FPosition := Value;
    DoPositonChange;
  end;
end;  

procedure TForm1.btn1Click(Sender: TObject);
begin
  test1.Position := StrToInt(edt1.Text);
end;  

procedure TForm1.OnTestPostionChange(Sender: TObject; Positon: Integer);
begin
  showmessage('Postion = '+IntToStr(Positon));
end;  

end.  

执行过程就是：窗体创建（给OnPositionChange赋值）--点击button（读取edt1中的值）---之后调用setposition（也许这就是绑定好的了吧）----DOPositionchange----执行FOnPositionChange（也就是OnTestPostionChange）。。。