How to bind data in gridview when insert click

  protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            Bindgrid();
        }
    }

    private void Bindgrid()
    {
        DataTable dummy = new DataTable();
        dummy.Columns.Add("ID");
        dummy.Columns.Add("Name");
        dummy.Columns.Add("InvestmentType");
        dummy.Rows.Add();
        GridView1.DataSource = dummy;
        GridView1.DataBind();
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        SqlCommand cmd = new SqlCommand("insert into Insert1(Name,InvestmentType) values(@Name,@InvestmentType)", con);
        cmd.CommandType = CommandType.Text;
        cmd.Parameters.AddWithValue("@Name", TextBox1.Text);
        cmd.Parameters.AddWithValue("@InvestmentType", TextBox2.Text);
        cmd.Connection = con;
        Label1.Text = "Inserted successfully..........";
        Bindgrid();
        try
        {
            con.Open();
            cmd.ExecuteNonQuery();
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally
        {
            con.Close();
            con.Dispose();
        }
    }
}