ASP.NET Tutorial/Cache/File Dependency
Содержание
Creating a Page Output Cache File Dependency
<source lang="csharp">
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">
<%= DateTime.Now.ToString("T") %>
<asp:GridView id="grdProducts" DataSourceID="srcProducts" Runat="server" /> <asp:XmlDataSource id="srcProducts" DataFile="Data.xml" Runat="server" />
</form>
</body> </html></source>
Object Caching File Dependency
<source lang="csharp">
<%@ 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">
Object Caching
File Dependency
<asp:Label ID="lblMessage" runat="server" />
<asp:GridView ID="gv" runat="server" />
<asp:Button ID="btnClear" runat="server" Text="Clear Cache" OnClick="btnClear_Click" /> <asp:Button ID="btnPost" runat="server" Text="Post" />
</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></source>