const
  NIF_INFO = $10;
  NIM_SETVERSION = $00000004;
  NOTIFYICON_VERSION = 3;
  NIM_SETFOCUS = $00000003;
  NIIF_INFO = $00000001;
  NIIF_WARNING = $00000002;
  NIIF_ERROR = $00000003;

  NIN_BALLOONSHOW = WM_USER + 2;
  NIN_BALLOONHIDE = WM_USER + 3;
  NIN_BALLOONTIMEOUT = WM_USER + 4;
  NIN_BALLOONUSERCLICK = WM_USER + 5;
  NIN_SELECT = WM_USER + 0;
  NINF_KEY = $1;
  NIN_KEYSELECT = NIN_SELECT or NINF_KEY;
  {上面列的可能不全，如果没有定义到的，可在 vs.net 中 vc7 中的 PlatformSDK/Include/ShellAPI.h 中找到}

TRAY_CALLBACK = WM_USER + $7258;

Type
  PNewNotifyIconData = ^TNewNotifyIconData;

  TDUMMYUNIONNAME = Record
    case Integer of
      0: (uTimeout: UINT);
      1: (uVersion: UINT);
  end;

  TNewNotifyIconData = Record
    cbSize: DWORD;
    Wnd: HWND;
    uID: UINT;
    uFlags: UINT;
    uCallbackMessage: UINT;
    hIcon: HICON;
    szTip: array [0..127] of Char;    //Version 5.0为128个，以前为64个
    dwState: DWORD;    //Version 5.0
    dwStateMask: DWORD;    //Version 5.0
    szInfo: array [0..255] of Char;   //Version 5.0
    DUMMYUNIONNAME: TDUMMYUNIONNAME;
    szInfoTitle: array [0..63] of Char;   //Version 5.0
    dwInfoFlags: DWORD;   //Version 5.0
  end;

var
  IconData: TNewNotifyIconData;

procedure AddSysTrayIcon;
begin
  IconData.cbSize := sizeof(IconData);
  IconData.Wnd := AllocateHWnd(SysTrayIconMsgHandler);    //Self.Handle;  {SysTrayIconMsgHandler 为后面定义的消息处理过程}
  IconData.uID := 0;
  IconData.uFlags := NIF_ICON or NIF_MESSAGE or NIF_TIP;
  IconData.uCallbackMessage := TRAY_CALLBACK;   //自定义回传消息
  IconData.hIcon := Image1.Picture.Icon.Handle;    //此处为一 Icon 的 Handle
  IconData.szTip := 'Please send me email.';
  if not Shell_NotifyIcon(NIM_ADD, @IconData) then
    showmessage('add fail');
end;

procedure ShowBalloonTips;
var
  TipInfo, TipTitle: string;
begin
  IconData.cbSize := sizeof(IconData);
  IconData.uFlags := NIF_INFO;

  TipInfo := 'Please send me email.';
  strPLCopy(IconData.szInfo, TipInfo, sizeof(IconData.szInfo) - 1);

  IconData.DUMMYUNIONNAME.uTimeout := 3000;

  TipTitle := 'Happyjoe@21cn.com';
  strPLCopy(IconData.szInfoTitle, TipTitle, sizeof(IconData.szInfoTitle) - 1);

  IconData.dwInfoFlags := NIIF_INFO;     //NIIF_ERROR;  //NIIF_WARNING;

  Shell_NotifyIcon(NIM_MODIFY, @IconData);
  //下面的代码实际上没有用，去掉也可以（至少目前这样认为）
  IconData.DUMMYUNIONNAME.uVersion := NOTIFYICON_VERSION;
  if not Shell_NotifyIcon(NIM_SETVERSION, @IconData) then
    showmessage('setversion fail');
end;

procedure DeleteSysTrayIcon;
begin
  DeallocateHWnd(IconData.Wnd);
  if not Shell_NotifyIcon(NIM_DELETE, @IconData) then
    showmessage('delete fail');
end;

  procedure SysTrayIconMsgHandler(var Msg: TMessage); message TRAY_CALLBACK;

procedure SysTrayIconMsgHandler(var Msg: TMessage);
begin
  case Msg.LParam of
    WM_MOUSEMOVE: ;
    WM_LBUTTONDOWN: ;
    WM_LBUTTONUP: ;
    WM_LBUTTONDBLCLK: ;
    WM_RBUTTONDOWN: ;
    WM_RBUTTONUP: ;
    WM_RBUTTONDBLCLK: ;
    //以下为新加入的消息
    NIN_BALLOONSHOW:     {当 Balloon Tips 弹出时执行}
      showmessage('NIN_BALLOONSHOW');
    NIN_BALLOONHIDE:    {当 Balloon Tips 消失时执行（例如 SysTrayIcon 被删除），但指定的 TimeOut 时间到或鼠标点击 Balloon Tips 后的消失不发送此消息}
      showmessage('NIN_BALLOONHIDE');  
    NIN_BALLOONTIMEOUT:        {当 Balloon Tips 的 TimeOut 时间到时执行}
      showmessage('NIN_BALLOONTIMEOUT');
    NIN_BALLOONUSERCLICK:    {当鼠标点击 Balloon Tips 时执行。注意：在XP下执行时 Balloon Tips 上有个关闭按钮，而且 Balloon Tips 一直显示（IconData.DUMMYUNIONNAME.uTimeout := 3000; 这句话设定的时间没有用，我的测试是这样的），如果鼠标点在按钮上将接收到 NIN_BALLOONTIMEOUT 消息。}
      showmessage('NIN_BALLOONUSERCLICK');
  end;
end;