unit Unit1; 
interface 
uses 
Windows, Messages, SysUtils,  
Classes, Graphics, Controls, Forms, 
Dialogs,ShellAPI; 

const 
WM_BARICON=WM_USER+200; 

type 
TForm1 = class(TForm) 
private 
    procedure WMSysCommand(var Message: TMessage); message WM_SYSCOMMAND; 
    procedure WMBarIcon(var Message:TMessage);message WM_BARICON; 
   { Private 
declarations } 
public 
   
{ Public declarations } 
end; 

var 
Form1: 
TForm1; 

implementation 

{$R *.DFM} 
procedure TForm1.WMSysCommand 
(var Message:TMessage); 
var 
   lpData:PNotifyIconData; 
begin 
if Message.WParam = SC_ICON then 
begin 
    //如果用户最小化窗口则将窗口隐藏并在任务栏上添加图标     
    lpData := new(PNotifyIconDataA); 
    lpData.cbSize := 88; 
    //SizeOf(PNotifyIconDataA); 
    lpData.Wnd := Form1.Handle; 
    lpData.hIcon := Form1.Icon.Handle; 
    lpData.uCallbackMessage := WM_BARICON; 
    lpData.uID :=0; 
    lpData.szTip := 'Samples'; 
    lpData.uFlags := NIF_ICON  or NIF_MESSAGE or NIF_TIP; 
    Shell_NotifyIcon(NIM_ADD,lpData); 
    dispose(lpData); 
    Form1.Visible := False; 
end 
else 
begin 
    //如果是其它的SystemCommand 消息则调用系统缺省处理函数处理之。     
    DefWindowProc(Form1.Handle,Message. 
    Msg,Message.WParam,Message.LParam); 
end; 
// 
end; 

procedure 
TForm1.WMBarIcon(var Message:TMessage); 
var 
   lpData:PNotifyIconData; 
begin 
if (Message.LParam = WM_LBUTTONDOWN) then 
   
begin 
    //如果用户点击任务栏图标则将图标删除并回复窗口。 
    lpData := new(PNotifyIconDataA); 
    lpData.cbSize := 88;//SizeOf(PNotifyIconDataA); 
    lpData.Wnd := Form1.Handle; 
    lpData.hIcon := Form1.Icon.Handle; 
    lpData.uCallbackMessage := WM_BARICON; 
    lpData.uID :=0; 
    lpData.szTip := 'Samples'; 
    lpData.uFlags := NIF_ICON or NIF_MESSAGE or NIF_TIP; 
    Shell_NotifyIcon(NIM_DELETE,lpData); 
    dispose(lpData); 
    Form1.Visible := True; 
   end; 
end; 

end.