How
to use Caching Dataset in Asp.Net…….
Cache
in Asp.Net: Caching
is a most important to use in Asp.Net web application. It is a technique of
storing frequently used data/information in memory, so that, when the same
data/information is needed next time, it could be directly retrieved from the
memory instead of being generated by the application. , this is an effective
way for improving web application’s performance.
For Example:
First we will declare Connection String in
web.config ………………………..
<configuration>
<connectionStrings>
<add name="strconn" connectionString="Data
Source=KUSHTIWARI-PC;Initial Catalog=test;Integrated Security=True"/>
</connectionStrings>
<system.web>
<compilation debug="true" targetFramework="4.0"/>
</system.web>
</configuration>
Code for Default.aspx……………………………………………….
<%@ Page Language="C#"
AutoEventWireup="true"
CodeFile="Default.aspx.cs"
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></title>
<style type="text/css">
.style1
{
width: 100%;
}
.style2
{
height: 22px;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div>
<table class="style1">
<tr>
<td colspan="2" style="color:Red">
<center><b><i> Caching DataSet in Asp.Net</i></b></center> </td>
</tr>
<tr>
<td colspan="2">
<center><asp:GridView ID="GridView1"
runat="server">
</asp:GridView></center>
</td>
</tr>
<tr>
<td align="right">
<asp:Button ID="btnloaddata"
runat="server"
onclick="btnloaddata_Click"
Text="Load Data" />
</td>
<td>
<asp:Button ID="btnClearCache"
runat="server"
onclick="btnClearCache_Click"
Text="Cache Clear" />
</td>
</tr>
<tr>
<td align="center"
class="style2"
colspan="2">
<asp:Label ID="lblmessage"
runat="server"
Text="Label"
Visible="False"></asp:Label>
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
Code for Default.aspx.cs……………………………………………….
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
// using namespace.....
using System.Configuration;
using System.Data.SqlClient;
using System.Data;
using System.Drawing;
public partial class _Default :
System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs
e)
{
}
// code fro how to apply cache........
protected void
btnloaddata_Click(object sender, EventArgs e)
{
if (Cache["empdata"]
== null)
{
string strcon = ConfigurationManager.ConnectionStrings["strconn"].ConnectionString;
using (SqlConnection
con = new SqlConnection(strcon))
{
SqlCommand cmd = new SqlCommand("Select
* from emp", con);
DataSet ds = new DataSet();
SqlDataAdapter da = new SqlDataAdapter(cmd);
da.Fill(ds);
lblmessage.Visible
= true;
lblmessage.ForeColor
= Color.Blue;
lblmessage.Text
= "This data are coming from Sql server ";
Cache["empdata"] = ds;
GridView1.DataSource
= ds;
GridView1.DataBind();
}
}
else
{
GridView1.DataSource
= (DataSet)Cache["empdata"];
GridView1.DataBind();
lblmessage.Text
= "";
lblmessage.Visible
= true;
lblmessage.ForeColor
= Color.Blue;
lblmessage.Text
= "This data are coming from Cache";
}
}
// code for clear cache............................
protected void
btnClearCache_Click(object sender, EventArgs e)
{
if (Cache["empdata"]
!= null)
{
Cache.Remove("empdata");
lblmessage.Visible
= true;
lblmessage.ForeColor
= Color.Red;
lblmessage.Text
= "The Dataset removed from cache";
}
else
{
lblmessage.Visible
= true;
lblmessage.ForeColor
= Color.Red;
lblmessage.Text
= "There is nothing in the Cache to be
removed";
}
}
}
Result:
After that when you will stop the Sql server Services from the steps given bellow
Step 1 – press window Button + R
Step 2 - write services.msc in Textox and press OK button you will see
new window like..
After stopping Sql Server
Services and again click LoadButton Button
you will find all data because data are coming from cache because data is store
in cache but when you will click CacheClear
Button then again click LoadData Button you will find this type error ..
A network-related or instance-specific error
occurred while establishing a connection to SQL Server. The server was not
found or was not accessible. Verify that the instance name is correct and that
SQL Server is configured to allow remote connections. (provider: Named Pipes
Provider, error: 40 - Could not open a connection to SQL Server)
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