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]()