Repeater中,寻找TextBox,Lable.等的值

          <asp:Repeater ID="reLibData" runat="server" 
              onitemcommand="reLibData_ItemCommand">
            <ItemTemplate>
                <!--show td-->
                   <td style=" padding:5px">
                    <div class="talStyle">
                       <table width="100%" border="0" cellspacing="1" cellpadding="2" style="font-size:12px">
                          <tr>
                            <td>需求数量</td>
                            <td><%#Eval("reserverenum")%></td>
                          </tr>

                          <tr>
                            <td>库存数量</td>
                            <td><asp:Label ID="labSaNum" runat="server" Text='<%#Eval("reserverenum")%>' ></asp:Label></td>
                          </tr>
                          <tr>
                            <td>出库数量</td>
                            <td><asp:TextBox ID="txtLibOutNum" runat="server" Width="30" MaxLength="4"></asp:TextBox>
                                <asp:RegularExpressionValidator ID="RegExtxtLibOutNum"  ControlToValidate="txtLibOutNum"
                                 runat="server" ValidationExpression="^[1-9][0-9]*$"  ErrorMessage="请输入大于0的数."></asp:RegularExpressionValidator>
                            </td>
                          </tr>
                         <tr>
                            <td align="center" align="center" colspan="2"><asp:LinkButton ID="lnkLibOut" runat="server"  Text="出 库" CommandArgument='<%#Eval("reserve_goods_id")%>' CommandName="comLibOut"></asp:LinkButton> &nbsp;&nbsp;<a href="###" onclick="updateData(<%#Eval("reserveid") %>)"> 查看订单 </a> </td>
                          </tr>
                         </table>
                    </div>
                </td>
             <!--end one show-->
              <%#( (Container.ItemIndex+1)%5 ==0)?"</tr><tr>":"" %>
            </ItemTemplate>
          </asp:Repeater>

        protected void reLibData_ItemCommand(object source, RepeaterCommandEventArgs e)
        {
            if (e.CommandName == "comLibOut")
            {
                Helper.Page.MsgShow(this, e.CommandArgument.ToString());
                TextBox _txtnum = (TextBox)reLibData.Items[e.Item.ItemIndex].FindControl("txtLibOutNum"); //出库数量
                int _liboutnum = Convert.ToInt32(_txtnum.Text.ToString() == "" ? "0" : _txtnum.Text.ToString() );
                if (_liboutnum<1)
                {
                    Helper.Page.MsgShow(this, "请输入一个大于0的数.");
                    return;
                }
                Label _labsanum = (Label)reLibData.Items[e.Item.ItemIndex].FindControl("labSaNum");       //库存数量
                int _datasavenum = Convert.ToInt32(_labsanum.Text.ToString());
            }
        }