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)。。。