Question

I have an application that has a main form and a system task tray icon. In the designer of the main form, I dragged the TrayIcon control on the form, so it is a child of the main form.

At this point, when the user presses the close button on the main form, it actually just hides it so that the application wont terminate, unless the user right clicks the TrayIcon and clicks exit. But, the main form has a lot of controls and resources, and when the main form is hidden, it still uses memory for those resources. My goal is to actually dispose of form so it doesn’t take up that memory while it is not being used.

Unless I am mistaken, and when the main form is hidden it doesn’t take up that memory anymore, but I don’t think that is the case.
I’m no expert on memory, I may even be completely mistaken on how memory management works, and thus this question is invalid.

Anyways, if I am correct in that when the main form is only hidden it still takes up memory that can be freed by fully closing the form, is there a way for me to actually close the main form without the application terminating? If so, I would need to create the TrayIcon with code in the Program class instead of in the class of the main form, correct?

Answer 1

No, that’s certainly not necessary. It is encouraged by the convenience of the designer but you can easily create an application that only creates a window on demand. You’ll have to write code instead. It doesn’t take a heckofalot, there’s a sample app with basic functionality. Edit the Program.cs file and make it look similar to this (icon required, I called it “SampleIcon”):

static class Program {
    [STAThread]
    static void Main() {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        var cms = new ContextMenuStrip();
        cms.Items.Add("Show", null, ShowForm);
        cms.Items.Add("Exit", null, ExitProgram);
        var ni = new NotifyIcon();
        ni.Icon = Properties.Resources.SampleIcon;
        ni.ContextMenuStrip = cms;
        ni.Visible = true;
        Application.Run();
        ni.Dispose();
    }

    private static void ShowForm(object sender, EventArgs e) {
        // Ensure the window acts like a singleton
        if (MainWindow == null) {
            MainWindow = new Form1();
            MainWindow.FormClosed += delegate { MainWindow = null; };
            MainWindow.Show();
        }
        else {
            MainWindow.WindowState = FormWindowState.Normal;
            MainWindow.BringToFront();
        }
    }

    private static void ExitProgram(object sender, EventArgs e) {
        Application.ExitThread();
    }

    private static Form MainWindow;
}