Hi Mehram,

Check this example. Now please take its reference and correct your code.

HTML

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server">
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css" />
    <style type="text/css">
        .img-circle
        {
            border-radius: 50%;
        }
       
        
        input[type="checkbox"][id^="cb"]
        {
            display: none;
        }
        
        label
        {
            border: 1px solid #fff;
            padding: 10px;
            display: block;
            position: relative;
            margin: 10px;
            cursor: pointer;
            -webkit-touch-callout: none;
            -webkit-user-select: none;
            -khtml-user-select: none;
            -moz-user-select: none;
            -ms-user-select: none;
            user-select: none;
        }
        
        label::before
        {
            background-color: white;
            color: white;
            content: " ";
            display: block;
            border-radius: 50%;
            border: 1px solid grey;
            position: absolute;
            top: -5px;
            left: -5px;
            width: 25px;
            height: 25px;
            text-align: center;
            line-height: 28px;
            transition-duration: 0.4s;
            transform: scale(0);
        }
        
        label img
        {
            height: 100px;
            width: 100px;
            transition-duration: 0.2s;
            transform-origin: 50% 50%;
        }
        
        :checked + label
        {
            border-color: #ddd;
        }
        
        :checked + label::before
        {
            content: "✓";
            background-color: grey;
            transform: scale(1);
        }
        
        :checked + label img
        {
            transform: scale(0.9);
            box-shadow: 0 0 5px #333;
            z-index: -1;
        }
    </style>
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
    <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
    <script type="text/javascript">
        //On Page Load
        $(function () {
            SetSelection();
        });

        //On UpdatePanel Refresh
        var prm = Sys.WebForms.PageRequestManager.getInstance();
        if (prm != null) {
            prm.add_endRequest(function (sender, e) {
                if (sender._postBackSettings.panelsToUpdate != null) {
                    SetSelection();
                }
            });
        };

        function SetSelection() {
            $('[id*=hfSelected]').val('0');
            $('[id*=lblImage]').on('click', function () {
                $(this).closest('td').find('input[type=checkbox]').click();
            });
            $('input[type = checkbox]').on('click', function () {
                var isSelected = $(this).closest('td').find('[id*=hfSelected]');
                if ($(isSelected).val() == "0") {
                    $(isSelected).val(1);
                } else {
                    $(isSelected).val(0);
                }
            });
        }
    </script>
    <section class="content-header">
        <h1>Voting </h1>
    </section>
    <asp:UpdatePanel ID="upContent" runat="server">
        <ContentTemplate>
            <section class="content">
                <div class="row">
                    <div class="col-xs-12">
                            <div class="box-body table-responsive">
                                <div class="row">
                                    <div class="col-xs-12">
                                        <table class="table table-bordered">
                                            <tr>
                                                <th>Company</th>
                                                <th>Election Year</th>
                                                <th></th>
                                            </tr>
                                            <tr>
                                                <td style="width: 200px;">
                                                    <asp:DropDownList ID="cboCompany" runat="server" CssClass="chzn-select ddst" Width="100%"></asp:DropDownList>
                                                </td>
                                                 
                                                <td style="width: 380px;">
                                                    <asp:DropDownList ID="cboElectionYear" runat="server" CssClass="chzn-select ddst" Width="100%" Enabled="true"></asp:DropDownList>
                                                </td>
                                                <td style="text-align: left;">
                                                    <asp:LinkButton ID="btnGetReport" runat="server" CssClass="btn btn-default btn-flat toolbtn" Style="float: left; margin: 0px;">Get Data</asp:LinkButton>
                                                </td>
                                            </tr>
                                        </table>
                                    </div>
                                </div>
                                <br />
                                <div class="row" id="divOptions" runat="server" visible="false">
                                    <div class="col-xs-12" style="text-align: center;">
                                        <asp:LinkButton ID="lnkExcel" runat="server" CssClass="gridbuttonred" style="padding:4px; border-radius:0px" Visible="false">Export to Excel</asp:LinkButton>
                                    </div>
                                </div>
                                <br />
                                <div class="row">
                                <div class="col-xs-12 col-lg-12 col-md-12 col- row">
                                    <asp:DataList ID="dlCustomers" runat="server" RepeatColumns="4" CellSpacing="5" RepeatLayout="Table"
                                        DataKeyField="ElectionContributorsID">                                         
                                        <ItemTemplate>
                                            <table class="table" border="0">
                                                <tr>
                                                    <th colspan="2"><b><%# Eval("MemberName") %></b></th>
                                                </tr>
                                                <tr>
                                                    <td colspan="2">
                                                    <input type="checkbox" id='cb<%#Eval("ElectionContributorsID") %>' /><label for='cb<%#Eval("ElectionContributorsID") %>'>
                                                        <asp:Image ID="lblImage" runat="server" CssClass="img-circle" Width="100px" hight="100px"
                                                            ImageUrl='<%#DataBinder.Eval(Container.DataItem, "PicPath")%>' /></label>
                                                        <asp:HiddenField ID="hfSelected" runat="server" />
                                                    </td>
                                                </tr>
                                                <tr>
                                                    <td>Phone:</td>
                                                    <td><%# Eval("MemberFatherName")%></td>
                                                </tr>
                                                <tr>
                                                    <td>Fax:</td>
                                                    <td><%# Eval("FamilyName")%></td>
                                                </tr>
                                            </table>
                                        </ItemTemplate>
                                    </asp:DataList>
                                    <asp:Button ID="Button1" Text="Save" runat="server" OnClick="OnSave" CssClass="btn btn-success" />
                                </div>
                            </div>
                        </div>
                    </div>
                </div>
            </section>
        </ContentTemplate>
        <Triggers>
            <asp:PostBackTrigger ControlID="lnkExcel" />
        </Triggers>
    </asp:UpdatePanel>
    <asp:UpdateProgress DisplayAfter="0" ID="MPG1" AssociatedUpdatePanelID="upContent"
        runat="server">
        <ProgressTemplate>
            <div id="overlay">
                <div id="modalprogress">
                    <div id="theprogress">
                        <img alt="indicator" src="Images/loading.gif" />
                        <br />
                        <br />
                        Please wait while system is updating ...
                    </div>
                </div>
            </div>
        </ProgressTemplate>
    </asp:UpdateProgress>
</asp:Content>

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        System.Data.DataTable dt = new System.Data.DataTable();
        dt.Columns.AddRange(new System.Data.DataColumn[] { 
            new System.Data.DataColumn("ElectionContributorsID", typeof(int)), 
            new System.Data.DataColumn("MemberName", typeof(string)), 
            new System.Data.DataColumn("PicPath", typeof(string)), 
            new System.Data.DataColumn("MemberFatherName", typeof(string)), 
            new System.Data.DataColumn("FamilyName", typeof(string)) });
        dt.Rows.Add(1, "Chrysanthemum", "~/Images/Chrysanthemum.jpg", "Chrysanthemum", "Flower");
        dt.Rows.Add(2, "Desert", "~/Images/Desert.jpg", "Desert", "Flower");
        dt.Rows.Add(3, "Hydrangeas", "~/Images/Hydrangeas.jpg", "Hydrangeas", "Flower");
        dt.Rows.Add(4, "Jellyfish", "~/Images/Jellyfish.jpg", "Jellyfish", "Flower");
        dt.Rows.Add(5, "Koala", "~/Images/Koala.jpg", "Koala", "Flower");
        dt.Rows.Add(6, "Lighthouse", "~/Images/Lighthouse.jpg", "Lighthouse", "Flower");
        dt.Rows.Add(7, "Penguins", "~/Images/Penguins.jpg", "Penguins", "Flower");
        dt.Rows.Add(8, "Tulips", "~/Images/Tulips.jpg", "Tulips", "Flower");
        this.dlCustomers.DataSource = dt;
        this.dlCustomers.DataBind();
    }
}
protected void OnSave(object sender, EventArgs e)
{
    int i = 0;
    foreach (DataListItem item in dlCustomers.Items)
    {
        bool isSelected = (item.FindControl("hfSelected") as HiddenField).Value == "1" ? true : false;
        if (isSelected)
        {
            string id = dlCustomers.DataKeys[item.ItemIndex].ToString();
            string path = (item.FindControl("lblImage") as System.Web.UI.WebControls.Image).ImageUrl;
            i += this.InsertDetails(id, path);
        }
    }

    ScriptManager.RegisterClientScriptBlock(sender as Control, this.GetType(), "alert", "alert('" + i.ToString() + " records inserted.')", true);
}
private int InsertDetails(string id, string path)
{
    int i = 0;
    string conString = System.Configuration.ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (System.Data.SqlClient.SqlConnection con = new System.Data.SqlClient.SqlConnection(conString))
    {
        string query = "INSERT INTO MemberDetails VALUES(@Id,@ImagePath)";
        System.Data.SqlClient.SqlCommand cmd = new System.Data.SqlClient.SqlCommand(query, con);
        cmd.Parameters.AddWithValue("@Id", id);
        cmd.Parameters.AddWithValue("@ImagePath", path);
        con.Open();
        i = cmd.ExecuteNonQuery();
        con.Close();
    }

    return i;
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Dim dt As System.Data.DataTable = New System.Data.DataTable()
        dt.Columns.AddRange(New System.Data.DataColumn() {
                            New System.Data.DataColumn("ElectionContributorsID", GetType(Integer)),
                            New System.Data.DataColumn("MemberName", GetType(String)),
                            New System.Data.DataColumn("PicPath", GetType(String)),
                            New System.Data.DataColumn("MemberFatherName", GetType(String)),
                            New System.Data.DataColumn("FamilyName", GetType(String))})
        dt.Rows.Add(1, "Chrysanthemum", "~/Images/Chrysanthemum.jpg", "Chrysanthemum", "Flower")
        dt.Rows.Add(2, "Desert", "~/Images/Desert.jpg", "Desert", "Flower")
        dt.Rows.Add(3, "Hydrangeas", "~/Images/Hydrangeas.jpg", "Hydrangeas", "Flower")
        dt.Rows.Add(4, "Jellyfish", "~/Images/Jellyfish.jpg", "Jellyfish", "Flower")
        dt.Rows.Add(5, "Koala", "~/Images/Koala.jpg", "Koala", "Flower")
        dt.Rows.Add(6, "Lighthouse", "~/Images/Lighthouse.jpg", "Lighthouse", "Flower")
        dt.Rows.Add(7, "Penguins", "~/Images/Penguins.jpg", "Penguins", "Flower")
        dt.Rows.Add(8, "Tulips", "~/Images/Tulips.jpg", "Tulips", "Flower")
        Me.dlCustomers.DataSource = dt
        Me.dlCustomers.DataBind()
    End If
End Sub
Protected Sub OnSave(ByVal sender As Object, ByVal e As EventArgs)
    Dim i As Integer = 0
    For Each item As DataListItem In dlCustomers.Items
        Dim isSelected As Boolean = If(TryCast(item.FindControl("hfSelected"), HiddenField).Value = "1", True, False)
        If isSelected Then
            Dim id As String = dlCustomers.DataKeys(item.ItemIndex).ToString()
            Dim path As String = TryCast(item.FindControl("lblImage"), System.Web.UI.WebControls.Image).ImageUrl
            i += Me.InsertDetails(id, path)
        End If
    Next

    ScriptManager.RegisterClientScriptBlock(TryCast(sender, Control), Me.GetType(), "alert", "alert('" & i.ToString() & " records inserted.')", True)
End Sub
Private Function InsertDetails(ByVal id As String, ByVal path As String) As Integer
    Dim i As Integer = 0
    Dim conString As String = System.Configuration.ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As Data.SqlClient.SqlConnection = New Data.SqlClient.SqlConnection(conString)
        Dim query As String = "INSERT INTO MemberDetails VALUES(@Id,@ImagePath)"
        Dim cmd As Data.SqlClient.SqlCommand = New Data.SqlClient.SqlCommand(query, con)
        cmd.Parameters.AddWithValue("@Id", id)
        cmd.Parameters.AddWithValue("@ImagePath", path)
        con.Open()
        i = cmd.ExecuteNonQuery()
        con.Close()
    End Using

    Return i
End Function

Screenshot