[AleD]

лови пример

Код:

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Edit1: TEdit;
    procedure Button1Click(Sender: TObject);
    procedure Button1MouseEnter(Sender: TObject);
    procedure Button1MouseLeave(Sender: TObject);
    procedure Button1MouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure Button1MouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  //
end;

procedure TForm1.Button1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
  b: Integer;
begin
  case Button of
    mbLeft: b := WM_LBUTTONDOWN;
    mbRight: b := WM_RBUTTONDOWN;
    mbMiddle: b := WM_MBUTTONDOWN;
  end;
  SendMessage(Button2.Handle,b,0,0);
end;

procedure TForm1.Button1MouseEnter(Sender: TObject);
begin
  SendMessage(Button2.Handle,CM_MOUSEENTER,0,0);
end;

procedure TForm1.Button1MouseLeave(Sender: TObject);
begin
  SendMessage(Button2.Handle,CM_MOUSELEAVE,0,0);
end;

procedure TForm1.Button1MouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
  b: Integer;
begin
  case Button of
    mbLeft: b := WM_LBUTTONUP;
    mbRight: b := WM_RBUTTONUP;
    mbMiddle: b := WM_MBUTTONUP;
  end;
  SendMessage(Button2.Handle,b,0,0);
end;

end.

визуально оно не одинаково, но по обработке событий идентично (события с мышью)