大家好，今天老師要我們作出如下圖的結果

但我目前只能做到這樣

以下是我的程式碼

        SqlConnection conn = null;
        SqlCommand command = null;
        private void button1_Click(object sender, EventArgs e)
        {
            using (conn = new SqlConnection("Data Source=.;Initial Catalog=Northwind;Integrated Security=True"))
            {
                using (SqlCommand command = new SqlCommand("select *from Customers", conn))
                {
                    conn.Open();
                    using (SqlDataReader datareader = command.ExecuteReader())
                    {

                        using (DataTable dataTable = new DataTable())
                        {
                          dataTable.Load(datareader);
                          this.dataGridView2.DataSource = dataTable;
                        }

                    }
                }
            }
        }
        private void button2_Click(object sender, EventArgs e)
        {
            categoriesTableAdapter1.Fill(northwindDataSet1.Categories);
            dataGridView1.DataSource = northwindDataSet1.Categories;
        }
        private void tabPage1_Click(object sender, EventArgs e)
        {

        }

        private void dataGridView2_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {
          
        }

        private void button3_Click(object sender, EventArgs e)
        {

            try
            {
                using (conn = new SqlConnection("Data Source=.;Initial Catalog=Northwind;Integrated Security=True"))
                {
                    conn.Open();
                    using (SqlCommand command = new SqlCommand("select *from Customers", conn))
                    {

                        using (SqlDataReader datareader = command.ExecuteReader())
                        {

                            //TreeNode tree = new TreeNode();

                            //while (datareader.Read())
                            //{
                            //    treeView1.Nodes.Add(new TreeNode(datareader["Country"].ToString()));
                            //}
                            for (int i = 0; i < dataGridView2.Rows.Count; i++)
                            {
                                int rowindex = i + 1;
                                TreeNode node = new TreeNode("Row_" + rowindex);
                                for (int j = 0; j < dataGridView2.Columns.Count; j++)
                                {
                                    node.Nodes.Add(dataGridView2.Rows[i].Cells[j].Value.ToString());

                                }
                                treeView1.Nodes.Add(node);
                            }


                        }


                    }
                }
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

想請問有甚麼辦法可以做到我們老師要的結果，希望能給我一個方向，謝謝