Refresh (Reload) GridView periodically at regular intervals in ASP.Net using C# and VB.Net

Hi theunclevince,

You didn't implemented the code correctly from the referenced article.

You need to add the GridView inside UpdatePanel and use the Timer OnTick event handler to refresh the GridView.

Refer below example.

HTML

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
    <asp:ScriptManager ID="ScriptManager1" runat="server">
    </asp:ScriptManager>
    <asp:UpdatePanel ID="UpdatePanel1" runat="server">
        <ContentTemplate>
            <asp:Label ID="lblTime" runat="server" />
            <br />
            <br />
            <asp:GridView ID="gvCustomers" runat="server" AutoGenerateColumns="false">
                <Columns>
                    <asp:BoundField DataField="CustomerId" HeaderText="Customer Id" />
                    <asp:BoundField DataField="Name" HeaderText="Name" />
                    <asp:BoundField DataField="Country" HeaderText="Country" />
                </Columns>
            </asp:GridView>
            <asp:Timer ID="Timer1" runat="server" OnTick="TimerTick" Interval="1000" />
        </ContentTemplate>
    </asp:UpdatePanel>
</asp:Content>

Namespaces

C#

using System.Data;

VB.Net

Imports System.Data

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        lblTime.Text = "Last Refreshed: " + DateTime.Now.ToString();
        this.BindGrid();
    }
}

protected void TimerTick(object sender, EventArgs e)
{
    lblTime.Text = "Last Refreshed: " + DateTime.Now.ToString();
    this.BindGrid();
}

protected void BindGrid()
{
    DataTable dt = new DataTable();
    dt.Columns.AddRange(new DataColumn[3] {
        new DataColumn("CustomerId"),
        new DataColumn("Name"),
        new DataColumn("Country")
    });
    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");
    gvCustomers.DataSource = dt.AsEnumerable().OrderBy(x => Guid.NewGuid()).CopyToDataTable();
    gvCustomers.DataBind();
}

VB.Net

Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        lblTime.Text = "Last Refreshed: " & DateTime.Now.ToString()
        Me.BindGrid()
    End If
End Sub

Protected Sub TimerTick(sender As Object, e As EventArgs)
    lblTime.Text = "Last Refreshed: " & DateTime.Now.ToString()
    Me.BindGrid()
End Sub

Protected Sub BindGrid()
    Dim dt As DataTable = New DataTable()
    dt.Columns.AddRange(New DataColumn(2) {
                        New DataColumn("CustomerId"),
                        New DataColumn("Name"),
                        New DataColumn("Country")})
    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")
    gvCustomers.DataSource = dt.AsEnumerable().OrderBy(Function(x) Guid.NewGuid()).CopyToDataTable()
    gvCustomers.DataBind()
End Sub

Screenshot