ASP.NET Tutorial/Cache/Item Dependency
cached with a dependency on an item in the cache named Products.
File: Default.aspx
<%@ Page Language="C#" %>
<%@ OutputCache Duration="3600" 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">
protected void Page_Load(object sender, EventArgs e)
{
Cache.Insert("Products", DateTime.Now);
Response.AddCacheItemDependency("Products");
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Product List Key Dependency</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<%= DateTime.Now.ToString("T") %>
<hr />
<asp:GridView
id="grdProducts"
DataSourceID="srcProducts"
Runat="server" />
<asp:SqlDataSource
id="srcProducts"
ConnectionString="<%$ ConnectionStrings:Products %>"
SelectCommand="SELECT Title, Director FROM Products"
Runat="server" />
<br /><br />
<a href="NextPage.aspx">Add Product</a>
</div>
</form>
</body>
</html>
File: NextPage.aspx
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void dtlProduct_ItemInserted(object sender, DetailsViewInsertedEventArgs e)
{
Cache.Remove("Products");
Response.Redirect("~/Default.aspx");
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Add Product Key Dependency</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h1>Add Product</h1>
<asp:DetailsView
id="dtlProduct"
DefaultMode="Insert"
DataSourceID="srcProducts"
AutoGenerateRows="false"
AutoGenerateInsertButton="true"
Runat="server" OnItemInserted="dtlProduct_ItemInserted">
<Fields>
<asp:BoundField
DataField="Title"
HeaderText="Title:" />
<asp:BoundField
DataField="Director"
HeaderText="Director:" />
</Fields>
</asp:DetailsView>
<asp:SqlDataSource
id="srcProducts"
ConnectionString="<%$ ConnectionStrings:Products %>"
InsertCommand="INSERT Products (Title, Director)
VALUES (@Title, @Director)"
Runat="server" />
</div>
</form>
</body>
</html>
Object Caching Item 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>Item 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" />
<br />
<br />
<asp:Button ID="btnInit" runat="server" Text="Initialize Keys" OnClick="btnInit_Click" />
<asp:Button ID="btnKey0" runat="server" Text="Change Key 0" OnClick="btnKey0_Click" />
</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; // necessary for CacheDependency
using System.Xml; // necessary for Xml stuff
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();
string[] fileDependsArray = {Server.MapPath("Data.xml")};
string[] cacheDependsArray = {"Depend0", "Depend1", "Depend2"};
CacheDependency cacheDepends = new CacheDependency
(fileDependsArray, cacheDependsArray);
Cache.Insert("GridViewDataSet", dsGrid, cacheDepends);
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("Data.xml"));
dsData = doc.DataSet;
return dsData;
}
protected void btnClear_Click(object sender, EventArgs e)
{
Cache.Remove("GridViewDataSet");
CreateGridView();
}
protected void btnInit_Click(object sender, EventArgs e)
{
Cache["Depend0"] = "This is the first dependency.";
Cache["Depend1"] = "This is the 2nd dependency.";
Cache["Depend2"] = "This is the 3rd dependency.";
}
protected void btnKey0_Click(object sender, EventArgs e)
{
Cache["Depend0"] = "This is a changed first dependency.";
}
}
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>