Problem when displaying one form within another

Question

I’m having trouble displaying one form inside another through a panel. The point is that by modifying the state of the main form of WindowState == FormWindowState.Normal for WindowState == FormWindowState.Maximized, the form opened in the panel does not follow the size of the main form, so:

Normal form:

Maximized form:

Another problem is that by passing the main form from normal to maximized with some form open in the panel, the main form does not fill the entire screen, thus:

Code used to open Forms on the panel:

public void AbrirFormulario(Type formType)
    {
        pnFormulários.Enabled = true;
        pnFormulários.Visible = true;
        this.SuspendLayout();

        if (btVoltarInicio.Enabled == false)
        {
            try
            {
                for (int i = 0; i < lstFormulario.Count; i++)
                {
                    lstFormulario[i].Close();
                    lstFormulario[i].Dispose();
                    lstFormulario[i] = null;
                }

                lstFormulario.Clear();

                Form form = (Form)Activator.CreateInstance(formType);
                form.WindowState = FormWindowState.Maximized;
                form.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
                form.TopLevel = false;

                pnFormulários.Controls.Add(form);
                form.Show();

                lstFormulario.Add(form);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }

            this.ResumeLayout(true);
            btVoltarInicio.Enabled = true;
            btVoltarInicio.Visible = true;
        }
        else
        {

        }
    }

Button to open some form:

private void btCadCategorias_Click(object sender, EventArgs e)
    {
        AbrirFormulario(typeof(cadastro_categoria));
    }

Answer 1

You can use the property Control.Dock set as Dock.Fill to fill in all the empty spacing.

Another way would be to create a Tablelayoutpanel and use Anchoring.