private void dgvMain_CurrentCellChanged(object sender, EventArgs e) { if (this.dgvMain.CurrentRow != null) { string TaskID = this.dgvMain.Rows[this.dgvMain.CurrentRow.Index].Cells["colTaskID"].Value.ToString(); Process.Dal.BillDal dal = new Process.Dal.BillDal(); DataTable dt = dal.GetBillTaskDetail(TaskID); this.dgSub.DataSource = dt; } }