Auto refresh data on page using AJAX

Public Sub BindData()

    con = New SqlConnection("Initial Catalog=Northwind; Data Source=localhost; Uid=sa; pwd=;")

    cmd.CommandText = "select * from Employees "

    cmd.Connection = con

    con.Open()

    da = New SqlDataAdapter(cmd)

    da.Fill(ds)

    cmd.ExecuteNonQuery()

    GridData.DataSource = ds

    GridData.DataBind()

End Sub

You can check your current time on page load.

Write this code

MyLabel.Text = System.DateTime.Now.ToString()

BindData()

and grid refresh time is

Protected Sub Timer1_Tick(ByVal sender As Object, ByVal e As EventArgs)

    Label1.Text = "Grid Refreshed at: " + DateTime.Now.ToLongTimeString()

End Sub

Here is HTML desing code

<form id="form1" runat="server">

     <asp:Label ID="Label2" runat="server" Text="This is Time, When The Full Page Load :" Font-Bold="true"></asp:Label>&nbsp;

     <asp:Label ID="MyLabel" runat="server"></asp:Label><br /><br />       

    <asp:ScriptManager ID="ScriptManager1" runat="server" />

        <div>

            <asp:Timer ID="Timer1" OnTick="Timer1_Tick" runat="server" Interval="30000">

            </asp:Timer>

        </div>

        <asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional" runat="server">

            <Triggers>

                <asp:AsyncPostBackTrigger ControlID="Timer1" EventName="Tick" />

            </Triggers>

            <ContentTemplate>

                <asp:Label ID="Label3" runat="server" Text="This is The Time when Only Data Grid will Referesh :" Font-Bold="true"></asp:Label>&nbsp;

                <asp:Label ID="Label1" runat="server" Text="Grid not refreshed yet."></asp:Label><br />

                <asp:Label ID="Label4" runat="server" Text="(Grid Will Referesh after Every 30 Sec)" Font-Bold="true"></asp:Label>&nbsp;

                <br /><br />

                <asp:DataGrid ID=GridData runat="server" Width="100%" GridLines="Both" HeaderStyle-BackColor="#999999" AutoGenerateColumns="false">

                    <Columns>

                        <asp:BoundColumn DataField="EmployeeID" HeaderText="Employee ID"></asp:BoundColumn>

                        <asp:BoundColumn DataField="FirstName" HeaderText="First Name"></asp:BoundColumn>

                         <asp:BoundColumn DataField="LastName" HeaderText="Last Name"></asp:BoundColumn>

                        <asp:BoundColumn DataField="City" HeaderText="City"></asp:BoundColumn>

                    </Columns>

                </asp:DataGrid>

            </ContentTemplate>

        </asp:UpdatePanel>     

    </form>

Here is final snapshot