學習 Message(8): 使用不同的消息結構

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

unit　Unit1;

interface

uses
　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;

interface

uses
　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;

interface

uses
　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.