关于 OnMouseWheelDown、OnMouseWheelUp 等事件的简单例子 - 回复 "巅枫" 的问题

问题来源: http://www.cnblogs.com/del/archive/2009/10/28/1591380.html#2006425

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测试准备, 在空白窗体上添加 Memo1 和 Button1, 然后激活 Form1 的如下事件(巅枫同学关心的):
OnMouseEnter、OnMouseLeave、OnMouseWheel、OnMouseWheelDown、OnMouseWheelUp, 还用到其 OnCreate 事件.

然后根据如下测试代码, 一试便知:

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unit Unit1;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls;



type

  TForm1 = class(TForm)

    Memo1: TMemo;

    Button1: TButton;

    procedure FormCreate(Sender: TObject);

    procedure FormMouseEnter(Sender: TObject);

    procedure FormMouseLeave(Sender: TObject);

    procedure FormMouseWheel(Sender: TObject; Shift: TShiftState;

      WheelDelta: Integer; MousePos: TPoint; var Handled: Boolean);

    procedure FormMouseWheelDown(Sender: TObject; Shift: TShiftState;

      MousePos: TPoint; var Handled: Boolean);

    procedure FormMouseWheelUp(Sender: TObject; Shift: TShiftState;

      MousePos: TPoint; var Handled: Boolean);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



procedure TForm1.FormCreate(Sender: TObject);

begin

  Memo1.ScrollBars := ssBoth;

  Self.AutoScroll := True;

end;



procedure TForm1.FormMouseEnter(Sender: TObject);

begin

  Memo1.Lines.Add('Form1_OnMouseEnter');

end;



procedure TForm1.FormMouseLeave(Sender: TObject);

begin

  Memo1.Lines.Add('Form1_OnMouseLeave');

end;



procedure TForm1.FormMouseWheel(Sender: TObject; Shift: TShiftState;

  WheelDelta: Integer; MousePos: TPoint; var Handled: Boolean);

begin

  Memo1.Lines.Add('Form1_OnMouseWheel');

end;



procedure TForm1.FormMouseWheelDown(Sender: TObject; Shift: TShiftState;

  MousePos: TPoint; var Handled: Boolean);

begin

  Memo1.Lines.Add('Form1_OnMouseWheelDown');

  Button1.Top := Button1.Top - 4;

end;



procedure TForm1.FormMouseWheelUp(Sender: TObject; Shift: TShiftState;

  MousePos: TPoint; var Handled: Boolean);

begin

  Memo1.Lines.Add('Form1_OnMouseWheelUp');

  Button1.Top := Button1.Top + 4;

end;



end.

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