why gv_SelectedIndexChanged not firing

Sandeep Kumar

I want to click on QR Code Annd Fire to gv_SelectedIndexChanged event,

But Not Firing

My Code Below is --Aspx

<%@ Page Title="" Language="C#" MasterPageFile="~/MasterIQMS.master" EnableEventValidation="false" AutoEventWireup="true" CodeFile="SamplePrepration.aspx.cs" Inherits="Reports_SamplePrepration" %>
<%@ Register Src="~/Web Controls/CustomPager.ascx" TagName="PagingControl" TagPrefix="uc1" %>
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>