if (!IsPostBack)

        {

            using (UsersDataContext con = new UsersDataContext())

            {

                Repeater1.DataSource = con.Users.ToList();

                Repeater1.DataBind();

            }

        }

    void Button1_Click(object sender, EventArgs e)

    {

       Label1.Text=Request["ck"];

    }

 <asp:Button ID="Button1" runat="server" Text="Button" />

            <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>

            <table style="background-color: navy; text-align: center;">

                <tr style="color: white; font-size: 20px;">

                    <%--全选用的纯元素--%>

                    <td>

                        <input type="checkbox" id="ckall" /><label for="ckall">全选</label></td>

                    <td>编号</td>

                    <td>用户名</td>

                </tr>

                <asp:Repeater ID="Repeater1" runat="server">

                    <ItemTemplate>

                        <tr style="background-color: white;">

                            <td>

                                <%--单选用的纯元素--%>

                                <input type="checkbox" name="ck" value='<%#Eval("Ids") %>' /></td>

                            <td><%#Eval("Ids") %></td>

                            <td><%#Eval("username") %></td>

                        </tr>

                    </ItemTemplate>

                </asp:Repeater>

            </table>

<script type="text/javascript">

    var ckall = document.getElementById("ckall");

    var cks = document.getElementsByName("ck");

    ckall.onclick = function () {

        for (var i = ; i < cks.length; i++) {

            cks[i].checked = this.checked;

        }

    }

    for (var i = ; i < cks.length; i++) {

        var count = ;

        for (var j = ; j < cks.length; j++) {

            //假设有一个 没选  count +1

            if (cks[j].checked == false)

                count++;

        }

        //都选   全选  选中状态

        if (count == ) {

            ckall.checked = true;

        }

        else {

            ckall.checked = false;

        }

    }

</script>