You haven't provided that what you tried, so assuming and creating a sample as per your requirement. I have taken a good reference from here
So here we go:-
Firstly, you need to create a database for your data to be fetched from. for that you need to create a connection string. The below one is the sample in which I have used the Northwind database
<connectionStrings>
<addname="constr"connectionString="Data Source = .\SQLExpress;
Initial Catalog = Northwind; Integrated Security = true"/></connectionStrings>
Secondly, we will also be needing a handler in this case which will handle your request of AutoComplete
<%@ WebHandler Language="C#" Class="Search_CS" %>
using System;
using System.Web;
using System.Data.SqlClient;
using System.Configuration;
using System.Text;
public class Search_CS : IHttpHandler {
public void ProcessRequest (HttpContext context) {
string prefixText = context.Request.QueryString["q"];
using (SqlConnection conn = new SqlConnection())
{
conn.ConnectionString = ConfigurationManager
.ConnectionStrings["constr"].ConnectionString;
using (SqlCommand cmd = new SqlCommand())
{
cmd.CommandText = "select ContactName from Customers where " +
"ContactName like @SearchText + '%'";
cmd.Parameters.AddWithValue("@SearchText", prefixText);
cmd.Connection = conn;
StringBuilder sb = new StringBuilder();
conn.Open();
using (SqlDataReader sdr = cmd.ExecuteReader())
{
while (sdr.Read())
{
sb.Append(sdr["ContactName"])
.Append(Environment.NewLine);
}
}
conn.Close();
context.Response.Write(sb.ToString());
}
}
}
public bool IsReusable {
get {
return false;
}
}}
After that, you need to call the javascript function in your aspx page, so that your autocomplete part will work.
<link href="css/jquery.autocomplete.css" rel="stylesheet" type="text/css" />
<script src="scripts/jquery-1.4.1.min.js" type="text/javascript"></script>
<script src="scripts/jquery.autocomplete.js" type="text/javascript"></script>
<script type="text/javascript">
$(document).ready(function() {
$("#<%=txtSearch.ClientID%>").autocomplete('Search_CS.ashx');
});
</script>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="txtSearch" runat="server"></asp:TextBox>
</div>
</form>
That's the thing which you need to implement.
Below is the image it will look like,
Also see the plugin documentation related.
https://api.jqueryui.com/autocomplete/
Jquery autocomplete category.
https://jqueryui.com/autocomplete/#categories
If you get stuck in these, kindly let us know. We will be glad to help you out.
