Handle the form’s Resize event. In this handler, you override the basic functionality of the Resize event to make the form minimize to the system tray and not to the taskbar. This can be done by doing the following in your form’s Resize event handler: Check whether the form’s WindowState property is set to FormWindowState.Minimized. If yes, hide your form, enable the NotifyIcon object, and show the balloon tip that shows some information. Once the WindowState becomes FormWindowState.Normal, disable the NotifyIcon object by setting its Visible property to false. Now, you want the window to reappear when you double click on the NotifyIcon object in the taskbar. For this, handle the NotifyIcon’s MouseDoubleClick event. Here, you show the form using the Show() method.
private void frmMain_Resize(object sender, EventArgs e)
{
if (FormWindowState.Minimized == this.WindowState)
{
mynotifyicon.Visible = true;
mynotifyicon.ShowBalloonTip(500);
this.Hide();
}
else if (FormWindowState.Normal == this.WindowState)
{
mynotifyicon.Visible = false;
}
}