學習 Message(6): 也可以直接覆蓋祖先類的 WndProc 或 Dispatch 方法來響應消息

覆蓋: WndProc

unit　Unit1;

interface

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

type
　TForm1　=　class(TForm)
　protected
　　procedure　WndProc(var　Message:　TMessage);　override;
　end;

var
　Form1:　TForm1;

implementation

{$R　*.dfm}

procedure　TForm1.WndProc(var　Message:　TMessage);
begin
　inherited;
　if　Message.Msg　=　WM_LBUTTONDOWN　then
　　ShowMessage('WndProc');
end;

end.

　　覆蓋: Dispatch

unit　Unit1;

interface

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

type
　TForm1　=　class(TForm)
　public
　　procedure　Dispatch(var　Message);　override;
　end;

var
　Form1:　TForm1;

implementation

{$R　*.dfm}

procedure　TForm1.Dispatch(var　Message);
begin
　inherited;
　if　TMessage(Message).Msg　=　WM_LBUTTONDOWN　then
　　ShowMessage('Dispatch');
end;

end.