Изучение архитектуры настроек ASP.NET

//———————————————————————————––––––––––––——————
//  <copyright file="NameValueSectionHandler.cs" company="Microsoft">
//
//  Copyright (c) 2002 Microsoft Corporation All rights reserved.
//  The use and distribution terms for this software are contained in the
//  file named license.txt, which can be found in the root of this
//  distribution. By using this software in any fashion, you are agreeing
//  to be bound by the terms of this license
//  You must not remove this notice, or any other, from this software.
//
//  </copyright>
//——————————––––––––––––———————————————————————
#if !LIB
namespace System.Configuration {
using System.Collections;
using System.Collections.Specialized;
using System.Xml;
using System.Globalization;
public class NameValueSectionHandler :
IConfigurationSectionHandler {
const string defaultKeyAttribute = "key";
const string defaultValueAttribute = "value";
public object Create(object parent, object context,
XmlNode section) {
return CreateStatic(parent, section, KeyAttributeName,
  ValueAttributeName);
}
internal static object CreateStatic(object parent,
XmlNode section) {
return CreateStatic(parent, section, defaultKeyAttribute,
  defaultValueAttribute);
}
internal static object CreateStatic(object parent, XmlNode
section, string keyAttriuteName, string valueAttributeName)
{
ReadOnlyNameValueCollection result;
//  start result off as a shallow clone of the parent
if (parent == null)
  result = new ReadOnlyNameValueCollection(new
  CaseInsensitiveHashCodeProvider(
  CultureInfo.InvariantCulture),
  new  CaseInsensitiveComparer(
  CultureInfo.InvariantCulture));
else {
  ReadOnlyNameValueCollection parentCollection =
  (ReadOnlyNameValueCollection)parent;
  result =
  new ReadOnlyNameValueCollection(parentCollection);
}
// process XML
HandlerBase.CheckForUnrecognizedAttributes(section);
foreach (XmlNode child in section.ChildNodes) {
  // skip whitespace and comments
  if (HandlerBase.IsIgnorableAlsoCheckForNonElement(
  child))
  continue;
  // handle <set>, <remove>, <clear> tags
  if (child.Name == "add") {
  String key = HandlerBase.RemoveRequiredAttribute(
    child, keyAttriuteName);
  String value = HandlerBase.RemoveRequiredAttribute(
    child, valueAttributeName, true
    /*allowEmptyString*/);
  HandlerBase.CheckForUnrecognizedAttributes(child);
  result[key] = value;
  }
  else if (child.Name == "remove") {
  String key = HandlerBase.RemoveRequiredAttribute(
    child, keyAttriuteName);
  HandlerBase.CheckForUnrecognizedAttributes(child);
  result.Remove(key);
  }
  else if (child.Name.Equals("clear")) {
  HandlerBase.CheckForUnrecognizedAttributes(child);
  result.Clear();    }
  else {
  HandlerBase.ThrowUnrecognizedElement(child);
  }
}
result.SetReadOnly();
return result;
}
protected virtual string KeyAttributeName {
get { return defaultKeyAttribute;}
}
protected virtual string ValueAttributeName {
get { return defaultValueAttribute;}
}
}
}
#endif

if (child.Name == "add") {
String key = HandlerBase.RemoveRequiredAttribute(child,
keyAttriuteName);
String value = HandlerBase.RemoveRequiredAttribute(child,
valueAttributeName, true/*allowEmptyString*/);
HandlerBase.CheckForUnrecognizedAttributes(child);
result[key] = value;
}