Showing Data In GridView Using Application State in VB.NET

In this article we will know how to display data from the database into a GridView by using Application State object.

Application State

We can declare variables, objects in the application state. If we assign any value in the application state it can be globally accessed in any WebPages of the current application.

Program

First add a Global Application Class to the current application.

Global.asax code

<%@ import Namespace="System.Data" %>
<%@ import Namespace="System.Data.SqlClient" %>
<%@ Application Language="VB" %>
<script runat="server">
    Dim strConnString As String = System.Configuration.ConfigurationManager.ConnectionStrings.Item("ConnectionString").ToString()
    Dim con As New SqlConnection(strConnString)
    Dim str As String
    Dim com As SqlCommand
    Dim ds As DataSet
    Dim da As SqlDataAdapter
    Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)
        ' Code that runs on application startup
        Application("sqlconstring") = str
        Application("sqlcon") = con
        Application("sqlcom") = com
        Application("sqldataset") = ds
        Application("sqldataadapter") = da
    End Sub
    Sub Application_End(ByVal sender As Object, ByVal e As EventArgs)
        ' Code that runs on application shutdown
    End Sub     
    Sub Application_Error(ByVal sender As Object, ByVal e As EventArgs)
        ' Code that runs when an unhandled error occurs
    End Sub
    Sub Session_Start(ByVal sender As Object, ByVal e As EventArgs)
        ' Code that runs when a new session is started
    End Sub
    Sub Session_End(ByVal sender As Object, ByVal e As EventArgs)
        ' Code that runs when a session ends.
        ' Note: The Session_End event is raised only when the sessionstate mode
        ' is set to InProc in the Web.config file. If session mode is set to StateServer
        ' or SQLServer, the event is not raised.
    End Sub  
</script>

Default.aspx code

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Untitled Page</title>
</head>
<
body>
    <form id="form1" runat="server">
    <div>
    <asp:GridView ID="GridView1" BackColor="#FF9999" runat="server">
    <HeaderStyle BackColor="#FFCC99" />
    </asp:GridView><br />
    <asp:Button ID="Button1" runat="server" Text="Display Records" />
    </div>
    </form>
</body>
</
html>

Default.aspx.vb code

Imports System.Data
Imports System.Data.SqlClient
Partial Class _Default
    Inherits System.Web.UI.Page
    Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) HandlesButton1.Click
        Try
            Application("sqlcon").open()
            Application("sqlconstring") = "select * from employee"
            Application("sqlcom") = New SqlCommand(Application("sqlconstring"), Application("sqlcon"))
            Application("sqldataadapter") = New SqlDataAdapter(Application("sqlcom"))
            Application("sqldataset") = New DataSet
            Application("sqldataadapter").fill(Application("sqldataset"), "employee")
            GridView1.DataSource = Application("sqldataset")
            GridView1.DataMember = "employee"
            GridView1.DataBind()
            Application("sqlcon").close()
        Catch ex As Exception
            Response.Write(ex.Message)
        End Try
    End Sub
End Class

Output 

Application-State-in-VB.NET.gif