script type="text/javascript">
function SelectAll(parentChk, ChildId, bigControlID) {
var oElements = document.getElementsByTagName("INPUT");
var bIsChecked = parentChk.checked;

for (i = 0; i oElements.length; i++) {
     if (IsCheckBox(oElements[i]) IsMatch(oElements[i].id, ChildId, bigControlID)) {
 oElements[i].checked = bIsChecked;
      }
   }
}

function IsMatch(id, ChildId, controlID) {
var sPattern = '^' + controlID + '_+.*' + ChildId + '$';
var oRegExp = new RegExp(sPattern);
if (oRegExp.exec(id))
 return true;
else
 return false;
}

function IsCheckBox(chk) {
       if (chk.type == 'checkbox') return true;
       else return false;
}
/script>
 
asp:Repeater ID="Repeater_xx" runat="server">
       HeaderTemplate>
   table>
         tr>
        th>選項/th>
        th>數據/th>
         /tr>
       /HeaderTemplate>
       ItemTemplate>
         tr>
       td>
     asp:CheckBox ID="CheckBox_ID" runat="server" Checked="false" />
       /td>
       td>
     asp:Label runat="server" ID="Label_ID" Text='%#Eval("Label_ID")%>'>/asp:Label>
       /td>
   tr>
      /ItemTemplate>
      FooterTemplate>
  /table>
      /FooterTemplate>
/asp:Repeater>   

asp:CheckBox runat="server" ID="CheckBoxCz" Text="全選/反選" onclick='SelectAll(this,"CheckBox_ID","Repeater_xx")'/>

input class="anniu" id="input_gs" type="submit" runat="server" onserverclick="Gssubmit_Click" value="操作" />

public void Gssubmit_Click(object sender, EventArgs e)
{
        for (int i = 0; i Repeater_xx.Items.Count; i++)
          {
                 //獲取復選框
                 CheckBox cb = (CheckBox)rpt_Paper.Items[i].FindControl("CheckBoxCz");
                 //判斷是否被選中
                 if(cb != null cb.Checked == true)
                 {
                   Label id = (Label)rpt_Paper.Items[i].FindControl("Lable_ID");
                   //獲取該行ID
                   int ID= Convert.ToInt32(Id.Text);
                  //相應操作
                    ......
                 }
          } 
}