This is done via the ShellAPI function Shell_NotifyIcon(). The following example shows how to create an application that uses this function. The example application shows a different icon in the system tray every second and shows the time in the title. The application responds to a right click of the mouse by showing a menu allowing the user to display a form or quit the application. Attempts to close the form result in the form hiding, but the tray application continues to run. Note that no task bar icon is shown for the form. To compile the application, you will need to create a form with a TPopupMenu and a TTimer component. You will also need to make modifications to the main project source file (TrayIt.dpr).

Example:

{TrayIt.dpr}

program TrayIt;

uses Windows, Forms, TrayIt in 'TrayIt .pas' {Form };

{$R *.RES}

begin Application.Initialize; Application.ShowMainForm := False; Application.CreateForm(TForm , Form ); ShowWindow(Application.Handle, SW_HIDE); Application.Run; end.

{TrayIt .pas}

unit TrayIt ;

interface

uses Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, Menus, ShellAPI, ExtCtrls;

type TForm = class(TForm) PopupMenu : TPopupMenu; Open : TMenuItem; Exit : TMenuItem; Timer : TTimer; procedure FormCreate(Sender: TObject); procedure Open Click(Sender: TObject); procedure Exit Click(Sender: TObject); procedure FormClose(Sender: TObject; var Action: TCloseAction); procedure Timer Timer(Sender: TObject); private { Private declarations } procedure WndProc(var Msg : TMessage); override; public { Public declarations } IconData : TNotifyIconData; IconCount : integer; end;

var Form : TForm ;

implementation

{$R *.DFM}

procedure TForm .WndProc(var Msg : TMessage); var p : TPoint; begin case Msg.Msg of WM_USER + : case Msg.lParam of WM_RBUTTONDOWN: begin GetCursorPos(p); PopupMenu .Popup(p.x, p.y); end end; end; inherited; end;

procedure TForm .FormCreate(Sender: TObject); begin BorderIcons := [biSystemMenu]; IconCount := 0; IconData.cbSize := sizeof(IconData); IconData.Wnd := Handle; IconData.uID := 00; IconData.uFlags := NIF_MESSAGE + NIF_ICON + NIF_TIP; IconData.uCallbackMessage := WM_USER + ; IconData.hIcon := Application.Icon.Handle; StrPCopy(IconData.szTip, Application.Title); Shell_NotifyIcon(NIM_ADD, @IconData); Timer .Interval := 000; Timer .Enabled := true; end;

procedure TForm .Open Click(Sender: TObject); begin Form .Show; ShowWindow(Application.Handle, SW_HIDE); end;

procedure TForm .Exit Click(Sender: TObject); begin Shell_NotifyIcon(NIM_DELETE, @IconData); Application.ProcessMessages; Application.Terminate; end;

procedure TForm .FormClose(Sender: TObject; var Action: TCloseAction); begin Action := caNone; Form .Hide; end;

procedure TForm .Timer Timer(Sender: TObject); begin case(IconCount) of 0 : IconData.hIcon := LoadIcon(0, IDI_APPLICATION); : IconData.hIcon := LoadIcon(0, IDI_ASTERISK); 2 : IconData.hIcon := LoadIcon(0, IDI_EXCLAMATION); 3 : IconData.hIcon := LoadIcon(0, IDI_HAND); 4 : IconData.hIcon := LoadIcon(0, IDI_QUESTION); 5 : IconData.hIcon := Application.Icon.Handle; end; inc(IconCount); if IconCount > 5 then IconCount := 0; Application.Title := TimeToStr(Now); StrPCopy(IconData.szTip, Application.Title); Shell_NotifyIcon(NIM_MODIFY, @IconData); end;

begin ShowWindow(Application.Handle, SW_HIDE); end.

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