Bind Gridview with $.post and $.get methods using JQquery in ASP.Net

Please refer below code

HTML

<div>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
    <script type="text/javascript">
        $(function () {
            $.get("HandlerCS.ashx", '{}', function (data) {
                OnSuccess(data);
            });
        });
        function OnSuccess(response) {
            var customers = response;
            var row = $("[id*=gvCustomers] tr:last-child").clone(true);
            $("[id*=gvCustomers] tr").not($("[id*=gvCustomers] tr:first-child")).remove();
            $.each(customers, function () {
                var customer = $(this)[0];
                $("td", row).eq(0).html(customer.CustomerId);
                $("td", row).eq(1).html(customer.ContactName);
                $("td", row).eq(2).html(customer.Country);
                $("[id*=gvCustomers]").append(row);
                row = $("[id*=gvCustomers] tr:last-child").clone(true);
            });
        }
    </script>
    <asp:GridView ID="gvCustomers" runat="server" AutoGenerateColumns="false">
        <Columns>
            <asp:BoundField ItemStyle-Width="150px" DataField="CustomerID" HeaderText="CustomerID" />
            <asp:BoundField ItemStyle-Width="150px" DataField="ContactName" HeaderText="CustomerID" />
            <asp:BoundField ItemStyle-Width="150px" DataField="Country" HeaderText="Country" />
        </Columns>
    </asp:GridView>
</div>

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        this.BindDummyRow();
    }
}

private void BindDummyRow()
{
    DataTable dummy = new DataTable();
    dummy.Columns.Add("CustomerID");
    dummy.Columns.Add("ContactName");
    dummy.Columns.Add("Country");
    dummy.Rows.Add();
    gvCustomers.DataSource = dummy;
    gvCustomers.DataBind();
}

HandlerCS.ashx

<%@ WebHandler Language="C#" Class="HandlerCS" %>

using System;
using System.Web;
using System.Data;
using System.Configuration;
using System.Data.SqlClient;
using System.Collections.Generic;
using System.Web.Script.Serialization;

public class HandlerCS : IHttpHandler
{
    public void ProcessRequest(HttpContext context)
    {
        string json = this.GetCustomersJSON();
        context.Response.ContentType = "text/json";
        context.Response.Write(json);
    }

    private string GetCustomersJSON()
    {
        List<object> customers = new List<object>();
        using (SqlConnection conn = new SqlConnection())
        {
            conn.ConnectionString = ConfigurationManager.ConnectionStrings["conString"].ConnectionString;
            using (SqlCommand cmd = new SqlCommand())
            {
                cmd.CommandText = "SELECT top 10 CustomerID, ContactName, Country FROM Customers";
                cmd.Connection = conn;
                conn.Open();
                using (SqlDataReader sdr = cmd.ExecuteReader())
                {
                    while (sdr.Read())
                    {
                        customers.Add(new
                        {
                            CustomerId = sdr["CustomerId"],
                            ContactName = sdr["ContactName"],
                            Country = sdr["Country"]
                        });
                    }
                }
                conn.Close();
            }
            return (new JavaScriptSerializer().Serialize(customers));
        }
    }

    public bool IsReusable
    {
        get
        {
            return false;
        }
    }
}

I hope this will help you out.