Storing and Reading Custom Settings from the web.config File

ASP.NET provides two ways to store information within the configuration file.The first

is to store simple name/value settings within an

<appSettings /> section,

The second is to create a custom configuration section that can store data

in any format.

In order to implement a custom configuration section handler, you must implement a

custom class that implements IConfigurationSectionHandler.The following is a partial

code sample for the new configuration section handler used for the ASP.NET

forums:

Imports System

Imports System.Collections

Imports System.Collections.Specialized

Imports System.Xml

Imports System.Configuration

Imports System.Web.Configuration

Namespace AspNetForums.Configuration

' *********************************************************************

' ForumsConfigurationHandler

'

' Class used by ASP.NET Configuration to load ASP.NET Forums configuration.

' ***********************************************************************/

Class ForumsConfigurationHandler

Implements IConfigurationSectionHandler

Public Overridable Overloads Function Create(ByVal parent As Object,

➥ ByVal configContext As Object, ByVal node As XmlNode) As Object

➥Implements IConfigurationSectionHandler.Create

Dim config As New ForumConfiguration(CType(parent,

ForumConfiguration))

config.LoadValuesFromConfigurationXml(node)

Return config

End Function

End Class

' *********************************************************************

' ForumConfiguration

'

' Class used to represent the configuration data for the ASP.NET Forums

' ***********************************************************************/

Public Class ForumConfiguration

Dim _pageSize As Integer = 25

' *****************************************************************

' ForumConfiguration

'

' Internal constructor for creating a new instance.

' ******************************************************************/

Public Sub New(ByVal parent As ForumConfiguration)

' Place holder for future work

End Sub

' *********************************************************************

' LoadValuesFromConfigurationXml

'

' Loads the forums configuration values.

' ******************************************************************/

Sub LoadValuesFromConfigurationXml(ByVal node As XmlNode)

Dim attributeCollection As XmlAttributeCollection = node.Attributes

' Get the attributes of the <forums> element

_pageSize =

Int32.Parse(attributeCollection("defaultPageSize").Value)

End Sub

' Properties

Public ReadOnly Property PageSize() As Integer

Get

Return _pageSize

End Get

End Property

End Class

End Namespace

This configuration section handler is compiled and then registered within an application.

It can then be used within web.config:

<configuration>

<configSections>

<sectionGroup name="system.web">

<section name="forums"

type="AspNetForums.Configuration.ForumsConfigurationHandler, AspNetForums" />

</sectionGroup>

</configSections>

<system.web>

<forums defaultPageSize = "25" />

</system.web>

</configuration>

Comments

This code example shows how you can create a custom configuration section. It's obviously

not a simple task. However, for controlling exactly how the configuration information

represents the data stored in the configuration file, it is the only option. If having a

custom configuration section seems to you like too much work just to store application

items, you're not alone.