在aspx頁中獲取DataGrid行序號

            <asp:DataGrid ID="DataGrid1" runat="server" AutoGenerateColumns="False" "/>
                <Columns>
                  <asp:BoundColumn HeaderText="序號" DataField="PR_NO_Line"></asp:BoundColumn>                       
            <asp:TemplateColumn HeaderText="單位">
                        <ItemTemplate>
                            <asp:TextBox ID="Pcs" Text="PCS" runat="server"></asp:TextBox>
                            <asp:RequiredFieldValidator ID="RequiredFieldValidator10" runat="server" ControlToValidate="Pcs"
                                ErrorMessage='<%# String.Format("第{0}列物品計量單位",Convert.ToInt32(DataBinder.Eval(Container,"ItemIndex"))+1) %>' ForeColor="red"
                                ValidationGroup="vs">*</asp:RequiredFieldValidator>&nbsp;
                        </ItemTemplate>
                    </asp:TemplateColumn>
<%--                    <asp:TemplateColumn HeaderText="交貨日期">
                        <ItemTemplate>
                            <esshs:InputCalendar ID="InputCalendar1" runat="server" />
                        </ItemTemplate>
                    </asp:TemplateColumn>
--%>                </Columns>
            </asp:DataGrid>