學習 Message(8): 使用不同的訊息結構

下面是同樣的四段程式, 但分別使用了不同的三種訊息結構:
TWMMouseMove、TWMMouse、TMessage

unit Unit1;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs;type  TForm1 = class(TForm)  protected    procedure WMMouseMove(var Message: TWMMouseMove); message WM_MOUSEMOVE;  end;var  Form1: TForm1;implementation{$R *.dfm}procedure TForm1.WMMouseMove(var Message: TWMMouseMove);var  x,y: Integer;begin  x := Message.XPos;  y := Message.YPos;  Text := Format('%d, %d', [x,y]);end;end.

unit Unit1;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs;type  TForm1 = class(TForm)  protected    procedure WMMouseMove(var Message: TWMMouse); message WM_MOUSEMOVE;  end;var  Form1: TForm1;implementation{$R *.dfm}procedure TForm1.WMMouseMove(var Message: TWMMouse);var  x,y: Integer;begin  x := Message.XPos;  y := Message.YPos;  Text := Format('%d, %d', [x,y]);end;end.

unit Unit1;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs;type  TForm1 = class(TForm)  protected    procedure WMMouseMove(var Message: TMessage); message WM_MOUSEMOVE;  end;var  Form1: TForm1;implementation{$R *.dfm}procedure TForm1.WMMouseMove(var Message: TMessage);var  x,y: Integer;begin  x := Message.LParamLo;  y := Message.LParamHi;  Text := Format('%d, %d', [x,y]);end;end.