1.双击datagridview中的一行，后台获取改行的一个或多个列

  private void dgvImport_DoubleClick(object sender, EventArgs e)
        {
            string documentNo = dgvImport.CurrentRow.Cells["DOCUMENT_NO"].Value.ToString();
            GetImportDetail(documentNo);

        }

2.dagagridview前添加checkbox按钮，可以选中多行，后台获取选中的多行的列

                string sel = this.dgvImportMaster.Rows[e.RowIndex].Cells["SELECTION"].Value.ToString();
                        string documentNO = this.dgvImportMaster.Rows[e.RowIndex].Cells["DOCUMENT_NO"].Value.ToString();

 3.单元格值更改时

/// <summary>
        /// 单元格值更改时发生
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void dgvExpExportDetail_CellValueChanged(object sender, DataGridViewCellEventArgs e)
        {
            if (dgvExpExportDetail.CurrentRow == null) return;
            if (dgvExpExportDetail.CurrentCell.OwningColumn.Name == "QUANTITY")
            {
                string filter = "COMMUNITY_CODE=\'" + dgvExpExportDetail.CurrentRow.Cells["COMMUNITY_CODE"].Value + "\' AND DOCUMENT_NO=\'" + dgvExpExportDetail.CurrentRow.Cells["DOCUMENT_NO"].Value + "\' AND ITEM_NO=\'" + dgvExpExportDetail.CurrentRow.Cells["ITEM_NO"].Value + "\'";
                DataRow[] rowList = dsExpDetail.Tables[0].Select(filter);
                if (rowList.Length < 0)
                {
                    return;
                }
                DataRow newRow = rowList[0];
                if (!string.IsNullOrEmpty(newRow["EXP_CODE"].ToString()))
                {
                    decimal quantity = 0;
                    if (!decimal.TryParse(dgvExpExportDetail.CurrentCell.Value.ToString(), out quantity))
                    {
                        MessageBox.Show("数量必须为数字!", "注意");
                        newRow["QUANTITY"] = newRow["INVENTORY"];
                        return;
                    }
                    if (quantity > decimal.Parse(newRow["INVENTORY"].ToString()))
                    {
                        MessageBox.Show("数量不能大于库存数量:" + newRow["INVENTORY"], "注意");
                        newRow["QUANTITY"] = newRow["INVENTORY"];
                        return;
                    }
                    newRow["QUANTITY"] = dgvExpExportDetail.CurrentCell.Value;
                }
            }
        }