首先在Form上放置一个TTrayIcon的控件，Lazarus的话还需要应用windows单元(Linux需要引用lclintf单元)，记得给TrayIcon的Icon指定一个图标。其它废话不多说具体核心代码如下：

procedure TForm1.TrayIcon1DblClick(Sender: TObject);
begin
  if Application.MainForm <> nil then
  begin
    Application.Restore;
    // Show the form itself
    if Application.MainForm.WindowState = wsMinimized then
      Application.MainForm.WindowState := wsNormal;
    Application.MainForm.Visible := True;
    // Bring the main form (or its modal dialog) to the foreground
   //这句很重要，不然显示后是最小化在任务栏的，还需要点击一下才能正常显示到屏幕上
    SetForegroundWindow(Application.Handle);
    TrayIcon1.Visible := False;
  end;
end;

procedure TForm1.FormWindowStateChange(Sender: TObject);
begin
  if WindowState = TWindowState.wsMinimized then
  begin
    if Application.MainForm <> nil then
    begin
      Application.MainForm.Visible := False;
      HideTaskbarIcon;
    end;
    TrayIcon1.Visible := True;
  end;
end;

procedure TForm1.HideTaskbarIcon;
begin
  if IsWindowVisible(Application.Handle) then
    ShowWindow(Application.Handle, SW_HIDE);
end;


procedure TForm1.ShowTaskbarIcon;
begin
  if not IsWindowVisible(Application.Handle) then
    ShowWindow(Application.Handle, SW_SHOW);
end;