I used this in aspx Page
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebApplication15.WebForm1" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
<script src="bootstrap-select.min.js"></script>
<link href="bootstrap-select.min.css" rel="stylesheet" />
<script src="jquery-1.12.4.min.js"></script>
<link href="bootstrap.css" rel="stylesheet" />
<script src="JQuery/jquery-1.12.4.min.js" type="text/javascript"> </script>
<script src="bootstrap.js" type="text/javascript"></script>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js" type="text/javascript"></script>
<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js"
type="text/javascript"></script>
<link href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/base/jquery-ui.css"
rel="Stylesheet" type="text/css" />
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Button ID="Button1" CssClass="btn btn-primary" runat="server" Text="Show" />
<asp:DropDownList ID="DropDownList2" runat="server" AutoPostBack="true" CssClass="selectpicker">
<asp:ListItem>All Employees</asp:ListItem>
<asp:ListItem>Single Employee</asp:ListItem>
<asp:ListItem>Range of Card No</asp:ListItem>
<asp:ListItem>Departments</asp:ListItem>
</asp:DropDownList>
</ContentTemplate>
</asp:UpdatePanel>
</div>
</form>
</body>
</html>
but DropdownList Disappearing...
and Also Visited this link but
https://codedump.io/share/Jus3LkWj4rTv/1/selectpicker-in-updatepanel-disappear-when-asyncpostback
Problem still same ..
if i would put it out side the content place holder then It will not effect after click the button inside the content place holder..
Kindly Help me out Thank in Advanced..
