การนำค่าจาก datagrid มาคำนวณ แล้ว บันทึกลง datagrid เหมือนเดิม จะต้องเขียนโค้ดอย่างไรบ้างค่ะ (Windows App + C#)

DataTable myTable = new DataTable();
//Create new Column in DataTable
myTable.Columns.Add(new DataColumn("Name", typeof(System.String)));
myTable.Columns.Add(new DataColumn("DateX", typeof(System.String)));
myTable.Columns.Add(new DataColumn("Price", typeof(System.String)));
int totalX = 0;
for (int i = 0; i < ds.Tables["Showdata"].Rows.Count; i++)
{
     DataRow dr = myTable.NewRow();
     dr["Name"] = ds.Tables["Showdata"].Rows["Name"];
     dr["DateX"] = ds.Tables["Showdata"].Rows["DateX"];
     dr["Price"] = ds.Tables["Showdata"].Rows["Price"];
     if (ds.Tables["Showdata"].Rows["Price"].ToString() != "")
     {
          totalX += Convert.ToInt32(ds.Tables["Showdata"].Rows["Price"]);
     }
     myTable.Rows.Add(dr);
}
lbCost.Text = totalX.ToString() + " บาท";
lbOrder.Text = ds.Tables["Showdata"].Rows.Count.ToString() + " รายการ";
DataRow drX = myTable.NewRow();
drX["Name"] = "**************";
drX["DateX"] = "รวม";
drX["Price"] = totalX.ToString();
myTable.Rows.Add(drX);
GridOder.DataSource = myTable;
DataGridTableStyle tableStyle = new DataGridTableStyle();
DataGridTextBoxColumn Name = new DataGridTextBoxColumn();
Name.Width = 100;
Name.MappingName = "Name";
Name.HeaderText = "ชื่อสินค้า";
tableStyle.GridColumnStyles.Add(Name);
DataGridTextBoxColumn DateX = new DataGridTextBoxColumn();
DateX.Width = 60;
DateX.MappingName = "DateX";
DateX.HeaderText = "วันที่แก้ไข";
tableStyle.GridColumnStyles.Add(DateX);
DataGridTextBoxColumn Price = new DataGridTextBoxColumn();
Price.Width = 50;
Price.MappingName = "Price";
Price.HeaderText = "ราคา";
tableStyle.GridColumnStyles.Add(Price);
GridOder.TableStyles.Clear();
GridOder.TableStyles.Add(tableStyle);