动态创建DataTable

//动态创建DataTable用来绑定到GridView。

DataTable dt_per = new DataTable();
        DataColumn column_per;
        column_per = new DataColumn();
        column_per.DataType = System.Type.GetType("System.String");
        column_per.ColumnName = "ord_nbr";
        column_per.ReadOnly = true;
        column_per.Unique = true;
        dt_per.Columns.Add(column_per);

        column_per = new DataColumn();
        column_per.DataType = System.Type.GetType("System.String");
        column_per.ColumnName = "ord_seq";
        dt_per.Columns.Add(column_per);

DataRow dtr_per;
                dtr_per = dt_per.NewRow();
                dtr_per["ord_nbr"] = dt_trdord.Rows[i][0].ToString();//dt_trdord另一个DataTable
                dtr_per["ord_seq"] = 方法(参数1, 参数2，……);
                dt_per.Rows.Add(dtr_per);

=======================================================

DataTable dt = new DataTable();
        dt.Columns.Add(DateTime.Today.AddMonths(-2).Month + "上上月");
        dt.Columns.Add(DateTime.Today.AddMonths(-1).Month + "上月");
        dt.Columns.Add(DateTime.Today.Month + "本月");
        DataRow dr;
        dr = dt.NewRow();
        decimal d1 = 0, d2 = 0, d3 = 0;

//这块可以对d1、d2、d3赋值

　　　dr[0] = d1;
        dr[1] = d2;
        dr[2] = d3;
        dt.Rows.Add();
        GridView_ID.DataSource = dt;
        GridView_ID.DataBind();