覆盖Form.WndProc来响应消息

 

源代码：

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
  private
    { Private declarations }
  public
    { Public declarations }
  protected
    procedure WndProc(var Message:TMessage);override;
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

{ TForm1 }

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

end;

end.

--------------------------------------------------------------

界面代码:

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 210
  ClientWidth = 310
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  PixelsPerInch = 96
  TextHeight = 13
end