程序代码：

        private DataTable table = null;

        private void Form1_Load(object sender, EventArgs e)
        {
            DataBase data = new DataBase();
            string sqlStr = "select * from Branch";
            table = data.getDataTable(sqlStr);
            this.dataGridView1.DataSource = table;
        }

        /// <summary>
        /// 增加数剧列,从数据源添加
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button1_Click(object sender, EventArgs e)
        {
            DataColumn colum = new DataColumn("数据源新加");
            table.Columns.Add(colum);
            foreach (DataRow row in table.Rows)
            {
                row["数据源新加"] = "测试数据";
            }
        }