c# - How to update selected rows in ListView -

i have listview in asp.net web form . want select rows , update selected after button click.
want use checkbox/checkboxlist . don't understand how send information row or column in selected row checkbox/checkboxlist item .
how can select rows, , update them , using checkbox/checkboxlist ?
use asp.net linq entity framework.
code

  <asp:button id="buttontest" runat ="server" onclick="buttontest_click" />  <asp:listview id="listview2" itemtype="doccat.models.reqinf" selectmethod="getreqf" onitemdatabound="listview2_itemdatabound"              datakeynames="requestn" enableviewstate="true" runat="server" updatemethod="listview2_updateitem" deletemethod="listview2_deleteitem" insertmethod="listview2_insertitem">              <layouttemplate>                  <div class="outercontainer" style="overflow: scroll">                      <table id="doctable">                          <thead>                              <tr>                                  <th>                                     Выбрать                                  </th>                                  <th>first</th>                                  <th>request</th>                                  <th>third</th>                                  <th>four</th>                              </tr>                          </thead>                          <tbody runat="server" id="itemplaceholder"></tbody>                      </table>                  </div>                               </layouttemplate>                <itemtemplate>                  <tr>                      <td> <asp:checkboxlist runat="server" id="checknew" ><asp:listitem>Выбрать</asp:listitem></asp:checkboxlist></td>                      <td>                 </td>                      <td><%# item.birthdate.date%></td>                      <td><%# item.f1 %></td>                      <td><%# item.f2 %></td>                      <td><%# item.f3 %></td>                  </tr>              </itemtemplate>          </asp:listview>

selected rows don't display in checkboxlist items , in string selecteditems :

        checkboxlist cblroles = listview2.items[0].findcontrol("checknew") checkboxlist;                    string selecteditems = "";            (int = 0; < cblroles.items.count; i++)          {              if (cblroles.items[i].selected)              {                  selecteditems = selecteditems + cblroles.items[i].value + ",";              }          }                        

i used kind of ui. first created table ui, created populate table method in code behind.i used ado.net data access.

note: create stored procs getting data , updating data after button click.

step1: write populate table method in create object checkbox used radio button.

                   using (mtablerow = new htmltablerow()){                     {                          #region radio button                          using (htmltablecell ltablecell = new htmltablecell())                         {                             radiobutton mradiobutton = new radiobutton();                                 mradiobutton.id = "radio" + listinfo.id;                                  mradiobutton.groupname = "rowselector1";                                 mradiobutton.autopostback = true;                                 mradiobutton.checked = false;                                  mradiobutton.checkedchanged += new eventhandler(availableradiobutton_checkedchanged);                                  ltablecell.attributes["class"] = "radiobutton";                                 ltablecell.controls.add(mradiobutton);                                  mtablerow.cells.add(ltablecell);                                  #endregion                          // add remaining columns                            // add table row table. 

step2: create method event click of checkbox.