asp.net vb版 cache 处理缓存实例

简单的实例，cache方法理解ASP.NET缓存 Cache之数据缓存

大家可以通过各种各样的方法去优化我们系统，本篇博文将介绍通过Cache方法来优化系统的性能，减轻系统的负担。

[html] view plain copy

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="cache.aspx.vb" Inherits="admin_cache" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<input type=submit OnServerClick="AddItemToCache" value="Add Item To Cache" runat="server"/>
<input type=submit OnServerClick="RemoveItemFromCache" value="Remove Item From Cache" runat="server"/>
</div>
</form>
</body>
</html>

[vb] view plain copy

Imports System.Web.Caching
Partial Class admin_cache
Inherits System.Web.UI.Page
Shared itemRemoved As Boolean = False
Shared reason As CacheItemRemovedReason
Dim onRemove As CacheItemRemovedCallback
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
'缓存技术，首先判断是否有缓存数据
If (itemRemoved) Then
Response.Write("RemovedCallback event raised.")
Response.Write("<BR>")
Response.Write("Reason: <B>" + reason.ToString() + "</B>")
Else
Response.Write("Value of cache key: <B>" + Server.HtmlEncode(CType(Cache("Key1"), String)) + "</B>")
End If
End Sub
Public Sub RemovedCallback(k As String, v As Object, r As CacheItemRemovedReason)
itemRemoved = True
reason = r
End Sub
Public Sub AddItemToCache(sender As Object, e As EventArgs)
'添加缓存数据，同时触发onRemove事件，itemRemoved变成真
onRemove = New CacheItemRemovedCallback(AddressOf Me.RemovedCallback)
If (IsNothing(Cache("Key1"))) Then
Cache.Add("Key1", "这里是缓存数据", Nothing, DateTime.Now.AddSeconds(10), Cache.NoSlidingExpiration, CacheItemPriority.High, onRemove)
End If
End Sub
Public Sub RemoveItemFromCache(sender As Object, e As EventArgs)
'移除缓存数据
If (Not IsNothing(Cache("Key1"))) Then
Cache.Remove("Key1")
End If
End Sub
End Class

Kalet