ASP.NET Tutorial/Cache/File Dependency — различия между версиями
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Версия 15:30, 26 мая 2010
Creating a Page Output Cache File Dependency
You can create a dependency between a cached page and a file (or set of files) on your hard drive.
When the file is modified, the cached page is automatically dropped and regenerated with the next page request.
<%@ Page Language="C#" %>
<%@ OutputCache Duration="9999" VaryByParam="none" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void Page_Load()
{
Response.AddFileDependency(MapPath("Data.xml"));
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Output Cache File Dependency</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<%= DateTime.Now.ToString("T") %>
<hr />
<asp:GridView
id="grdProducts"
DataSourceID="srcProducts"
Runat="server" />
<asp:XmlDataSource
id="srcProducts"
DataFile="Data.xml"
Runat="server" />
</div>
</form>
</body>
</html>
Object Caching File Dependency
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" 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>Object Caching</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h1>Object Caching</h1>
<h2>File Dependency</h2>
<asp:Label ID="lblMessage" runat="server" />
<br />
<br />
<asp:GridView ID="gv" runat="server" />
<br />
<asp:Button ID="btnClear" runat="server" Text="Clear Cache" OnClick="btnClear_Click" />
<asp:Button ID="btnPost" runat="server" Text="Post" />
</div>
</form>
</body>
</html>
File: Default.aspx.cs
using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Web.Caching;
using System.Xml;
public partial class Default_aspx : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
CreateGridView();
}
private void CreateGridView()
{
DataSet dsGrid;
dsGrid = (DataSet)Cache["GridViewDataSet"];
if (dsGrid == null)
{
dsGrid = GetDataSet();
CacheDependency fileDepends = new CacheDependency(Server.MapPath("NorthWind.xml"));
Cache.Insert("GridViewDataSet", dsGrid, fileDepends);
lblMessage.Text = "Data from XML file.";
}
else
{
lblMessage.Text = "Data from cache.";
}
gv.DataSource = dsGrid.Tables[0];
gv.DataBind();
}
private DataSet GetDataSet()
{
DataSet dsData = new DataSet();
XmlDataDocument doc = new XmlDataDocument();
doc.DataSet.ReadXml(Server.MapPath("NorthWind.xml"));
dsData = doc.DataSet;
return dsData;
}
protected void btnClear_Click(object sender, EventArgs e)
{
Cache.Remove("GridViewDataSet");
CreateGridView();
}
}
File: NorthWind.xml
<?xml version="1.0" encoding="UTF-16" ?>
<ROOT>
<Customers CustomerID="A" CompanyName="A" ContactName="Dan" ContactTitle="Sales" Address="Str. 57" City="Berlin" PostalCode="11111" Country="Germany" Phone="030-0074321" Fax="030-0076545" />
<Customers CustomerID="B" CompanyName="B" ContactName="Ana" ContactTitle="Owner" Address="Road 22" City="New York" PostalCode="00000" Country="Mexico" Phone="(555) 555-4729" Fax="(5) 555-3745" />
</ROOT>