学习 Message(12): 整合鼠标 Down 消息

unit Unit1;



interface



uses

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

  Dialogs;



type

  TForm1 = class(TForm)

  protected

    procedure WMLButtonDown(var Message: TWMLButtonDown); message WM_LBUTTONDOWN;

    procedure WMMButtonDown(var Message: TWMMButtonDown); message WM_MBUTTONDOWN;

    procedure WMRButtonDown(var Message: TWMRButtonDown); message WM_RBUTTONDOWN;

    procedure MyMouseDown(Button: TMouseButton; X, Y: Integer);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



procedure TForm1.MyMouseDown(Button: TMouseButton; X,Y: Integer);

var

  btn: string;

begin

  case Button of

    mbLeft:   btn := '左键';

    mbRight:  btn := '右键';

    mbMiddle: btn := '中键';

  end;

  ShowMessageFmt('%s: %d,%d', [btn,X,Y]);

end;



procedure TForm1.WMLButtonDown(var Message: TWMLButtonDown);

begin

  MyMouseDown(mbLeft, Message.XPos, Message.YPos);

end;



procedure TForm1.WMMButtonDown(var Message: TWMMButtonDown);

begin

  MyMouseDown(mbMiddle, Message.XPos, Message.YPos);

end;



procedure TForm1.WMRButtonDown(var Message: TWMRButtonDown);

begin

  MyMouseDown(mbRight, Message.XPos, Message.YPos);

end;



end.