Delphi 使用自定义消息

1、先用Const 定义一个常量，例如 const WM_MyMessage=WM_USER+$200;
2、在要实现的unit中定义一个私有方法
procedure doMyMessage(var msg:TMessage);message WM_MyMessage;
3、实现这个私有方法
procedure TForm1.doMyMessage(var msg:TMessage);
begin
//
if msg.Msg= WM_MyMessage then
showmessage('好啊')
else
showmessage('不好');

end;

4、最重要 把这个消息广播出去 Form1.Perform(WM_MyMessage,0,0);

下面是实现的代码

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;
const WM_MyMessage=WM_USER+$200;

type
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
procedure doMyMessage(var msg:TMessage);message WM_MyMessage;
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.doMyMessage(var msg:TMessage);
begin
//
if msg.Msg= WM_MyMessage then
showmessage('好啊')
else
showmessage('不好');

end;

procedure TForm1.Button1Click(Sender: TObject);

begin
Form1.Perform(WM_MyMessage,0,0);

end;

end.