Trucchi per migliorare i Windows Form

Aggiungere un form all'interno di un panel come controllo

private void openChildForm(Form childForm)
{
    if (activeForm != null) activeForm.Close();
    activeForm = childForm;
    childForm.TopLevel = false;
    childForm.FormBorderStyle = FormBorderStyle.None;
    childForm.Dock = DockStyle.Fill;
    panelChildForm.Controls.Add(childForm);
    panelChildForm.Tag = childForm;
    childForm.BringToFront();
    childForm.Show();
}

Bordi del form tondi

[DllImport("Gdi32.dll", EntryPoint = "CreateRoundRectRgn")]
private static extern IntPtr CreateRoundRectRgn(int nLeftRect, int nTopRect, int nRightRect, int nBottomRect, int nWidthEllipse, int nHeightEllipse);

...

CostruttoreForm()
{
    ...
    Region = System.Drawing.Region.FromHrgn(CreateRoundRectRgn(0, 0, Width, Height, 25, 25));
    ...