افزايش كارآئی برنامه های وب در ASP.NET 2.0

ايجاد cache dependency در بانك اطلاعاتی NORTHWND

<%@ Page Language="VB" Culture="fa-IR" UICulture="fa-IR" %>
<%@ import Namespace="system.Data" %>
<%@ import Namespace="system.Data.SqlClient" %>
<%@ Import Namespace="System.Web.Configuration" %>
<Script runat="server">
Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not Me.IsPostBack Then
    lblInfo.Text &= "ايجاد آيتم وابسته<br />"
     Cache.Remove("CachedItem")
   ' Employees ايجاد يك وابستگی برای جدول
     Dim dependency As New SqlCacheDependency("Northwind", "Employees")
     Dim dt As DataTable = GetEmployeeTable()
     lblInfo.Text &= "اضافه كردن آيتم مورد نظر به cache<br />"
     Cache.Insert("CachedItem", dt, dependency)
End If
End Sub
' =================================================================
Private connectionString As String =_
          WebConfigurationManager.ConnectionStrings("NORTHWNDConnectionString").ConnectionString
Function GetEmployeeTable() As DataTable
Dim con As New SqlConnection(connectionString)
Dim sql As String = "SELECT * FROM Employees"
Dim da As New SqlDataAdapter(sql, con)
Dim ds As New DataSet()
da.Fill(ds, "Employees")
Return ds.Tables(0)
End Function
' ==================================================================
Sub cmdGetItem_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmdGetItem.Click
If Cache("CachedItem") Is Nothing Then
   lblInfo.Text &= "آيتم مورد نظر در cache موجود نمی باشد<br />"
Else
lblInfo.Text &= "آيتم مورد نظر همچنان در cache موجود است<br />"
End If
End Sub
' =================================================================
Sub cmdModify_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmdModify.Click
Dim con As New SqlConnection(connectionString)
' بهنگام سازی بانك اطلاعاتی
Dim sql As String = "UPDATE Employees SET LastName='sakha ravesh' WHERE LastName='srco'"
Dim cmd As New SqlCommand(sql, con)
Try
   con.Open()
   cmd.ExecuteNonQuery()
Finally
con.Close()
End Try
lblInfo.Text &= "بهنگام سازی بانك به تمام رسيد ، تا اتمام زمان polling منتظر بمانيد<br />"
End Sub
' =================================================================
</Script>

<html xmlns="http://www.w3.org/1999/xhtml" dir="rtl" >
<head id="Head1" runat="server">
   <title>Untitled Page</title>
</head>
<body style="font-family: Tahoma">
     <form id="form1" runat="server">
       <div>
           <asp:Button ID="cmdModify" runat="server" Height="24px" Text="تغيير جدول"
                              Width="103px" Font-Names="Tahoma" />
           <asp:Button ID="cmdGetItem" runat="server" Height="24px"
                              Text="بررسی آيتم cache شده"
                              Width="180px" Font-Names="Tahoma" /><br /><br />
           <asp:Label ID="lblInfo" runat="server" BackColor="LightYellow" BorderStyle="Groove"
                            BorderWidth="2px" Font-Names="Tahoma" Font-Size="X-Small" Height="192px"
                            Width="536px"></asp:Label>
       </div>
    </form>
   </body>
</html>