Question

i would like to know what is the correct way to create a fullscreen view of a tabpage control. This page has other controls, and that controls has various events that are subscribed. I was trying creating a new fullscreen form and copy all controls of the tabs to that form, but with this approach i need to resubscribe every control to the corresponding handler. If i only add the references the subscription remains but when the fullscreen form is close also the referenced copied controls are lost.

Answer 1

This can be elegantly done by Winforms’ support for reparenting a control. You could move it to a temporary form that’s displayed full-screen. All the normal event handlers still work as usual. Here’s a sample implementation, it works for any control:

    public static void ShowFullScreen(Control ctl) {
        // Setup host form to be full screen
        var host = new Form();
        host.FormBorderStyle = FormBorderStyle.None;
        host.WindowState = FormWindowState.Maximized;
        host.ShowInTaskbar = false;
        // Save properties of control
        var loc = ctl.Location;
        var dock = ctl.Dock;
        var parent = ctl.Parent;
        var form = parent;
        while (!(form is Form)) form = form.Parent;
        // Move control to host
        ctl.Parent = host;
        ctl.Location = Point.Empty;
        ctl.Dock = DockStyle.Fill;
        // Setup event handler to restore control back to form
        host.FormClosing += delegate {
            ctl.Parent = parent;
            ctl.Dock = dock;
            ctl.Location = loc;
            form.Show();
        };
        // Exit full screen with escape key
        host.KeyPreview = true;
        host.KeyDown += (KeyEventHandler)((s, e) => {
            if (e.KeyCode == Keys.Escape) host.Close();
        });
        // And go full screen
        host.Show();
        form.Hide();
    }

Sample usage:

    private void button1_Click(object sender, EventArgs e) {
        ShowFullScreen(tabControl1);
    }