ASP.Net/ADO.net Database/SqlCacheDependencyAdmin — различия между версиями

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Текущая версия на 11:50, 26 мая 2010

Use SqlCacheDependencyAdmin to GetTablesEnabledForNotifications

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="Default_aspx" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.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" runat="server" DataSourceID="SqlDataSource1" AutoGenerateColumns="False"
            DataKeyNames="au_id">
            <Columns>
                <asp:BoundField ReadOnly="True" HeaderText="au_id" DataField="au_id" SortExpression="au_id">
                </asp:BoundField>
                <asp:BoundField HeaderText="au_lname" DataField="au_lname" SortExpression="au_lname">
                </asp:BoundField>
                <asp:BoundField HeaderText="au_fname" DataField="au_fname" SortExpression="au_fname">
                </asp:BoundField>
                <asp:BoundField HeaderText="phone" DataField="phone" SortExpression="phone"></asp:BoundField>
                <asp:BoundField HeaderText="address" DataField="address" SortExpression="address"></asp:BoundField>
                <asp:BoundField HeaderText="city" DataField="city" SortExpression="city"></asp:BoundField>
                <asp:BoundField HeaderText="state" DataField="state" SortExpression="state"></asp:BoundField>
                <asp:BoundField HeaderText="zip" DataField="zip" SortExpression="zip"></asp:BoundField>
                <asp:CheckBoxField HeaderText="contract" SortExpression="contract" DataField="contract">
                </asp:CheckBoxField>
            </Columns>
        </asp:GridView>
        <asp:SqlDataSource ID="SqlDataSource1" 
                           runat="server"  
                           EnableCaching="True"  
                           SqlCacheDependency="Pubs:Authors"
                           SelectCommand="SELECT * FROM [authors]"
                           ConnectionString="<%$ ConnectionStrings:pubsConnectionString %>">
        </asp:SqlDataSource>
        <asp:Button ID="Button1" runat="server" Text="Enable Notifications" Width="181px" /><br />
    </div>
    </form>
</body>
</html>
File: Default.aspx.vb

Partial Class Default_aspx
    Inherits System.Web.UI.Page
    Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        EnableNotification("Authors")
    End Sub
    Public Sub EnableNotification(ByVal tableName As String)
        Dim connStr As String = "Server=.\SQLEXPRESS;Integrated Security=True;Database=pubs;Persist Security Info=True"
        Dim mustEnable As Boolean = True
        Try
            Dim tablesEnabled() As String
            tablesEnabled = _
               SqlCacheDependencyAdmin.GetTablesEnabledForNotifications(connStr)
            If (tablesEnabled IsNot Nothing) Then
                Dim table As String
                Response.Write("<b>Tables Enabled For " & _
                               "Notification</b><br/>")
                For Each table In tablesEnabled
                    Response.Write(table & "<br>")
                    If (table.ToString.Equals(tableName)) Then
                        mustEnable = False
                    End If
                Next
            End If
        Catch ex As Exception
            mustEnable = True
        End Try
        If mustEnable Then
            SqlCacheDependencyAdmin.EnableNotifications(connStr)
            SqlCacheDependencyAdmin. _
            EnableTableForNotifications(connStr, tableName)
            Response.Write(tableName & "<br>")
        End If
    End Sub
End Class