Add new Columns to existing DataTable with data using C# .Net

Please refer this code

HTML

<asp:GridView ID="GridView1" HeaderStyle-BackColor="#3AC0F2" HeaderStyle-ForeColor="White"
    runat="server" AutoGenerateColumns="false">
    <Columns>
        <asp:BoundField DataField="Id" HeaderText="Id" ItemStyle-Width="30" />
        <asp:BoundField DataField="Name" HeaderText="Name" ItemStyle-Width="150" />
        <asp:BoundField DataField="Country" HeaderText="Country" ItemStyle-Width="150" />
        <asp:BoundField DataField="MobileNumber" HeaderText="MobileNumber" ItemStyle-Width="150" />
        <asp:BoundField DataField="City" HeaderText="City" ItemStyle-Width="150" />
    </Columns>
</asp:GridView>

Namespaces

using System.Data;

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        DataTable dt = new DataTable();
        dt.Columns.AddRange(new DataColumn[3] { new DataColumn("Id", typeof(int)),
                        new DataColumn("Name", typeof(string)),
                        new DataColumn("Country",typeof(string)) });
        dt.Rows.Add(1, "John Hammond", "United States");
        dt.Rows.Add(2, "Mudassar Khan", "India");
        dt.Rows.Add(3, "Suzanne Mathews", "France");
        dt.Rows.Add(4, "Robert Schidner", "Russia");
        DataTable dt2 = new DataTable();
        dt2.Columns.Add("MobileNumber");
        dt2.Columns.Add("City");
        dt2.Rows.Add("111111111", "Washington");
        dt2.Rows.Add("222222222", "Mumbai");
        dt2.Rows.Add("333333333", "Paris");
        dt2.Rows.Add("333333333", "Paris");
        //It will skip this row as dt rows count is less than dt2 rows count
        dt2.Rows.Add("333333333", "Paris");
        for (int i = 0; i < dt2.Columns.Count; i++)
        {
            dt.Columns.Add(dt2.Columns[i].ColumnName);
        }
        for (int i = 0; i < dt2.Rows.Count; i++)
        {
            if (i >= dt.Rows.Count)
            {
                break;
            }
            else
            {
                dt.Rows[i]["MobileNumber"] = dt2.Rows[i]["MobileNumber"];
                dt.Rows[i]["City"] = dt2.Rows[i]["City"];
            }
        }
        GridView1.DataSource = dt;
        GridView1.DataBind();
    }
}

Screenshot