如何使用IConfigurationSectionHandler这个接口

Question

参考
In config:<Y>
        <XConfiguration>
                <add key="DataAccess.ConnectionString" value="user id=user;password=pwd;initial catalog=blub;data source=localhost" />
        </XConfiguration>
</Y>
Then:public class XConfiguration :
System.Configuration.IConfigurationSectionHandler
{
        public object Create(object parent, object input, XmlNode section)
        {
            
                System.Collections.Specialized.NameValueCollection config;
                        
                try
                {
                        config =
(NameValueCollection)ConfigurationSettings.GetConfig("Y/XConfiguration");
                }
                catch
                {
                        config = null;
                }
                if (config != null)
                {
                        s_ConnectionString = config["DataAccess.ConnectionString"]; 
                }
        }

Answer 1

Create Method由系统回调，你首先要调用GetConfig Method。参考：MyConfig.csusing System;
using System.Web;
using System.Xml;
using System.Configuration;namespace MyConfig
{
   public enum LevelSetting
   {
      High,
      Medium,
      Low,
      None
   }
   public class MyConfigSectionHandler : IConfigurationSectionHandler
   {
      public virtual object Create(object parent,object configContext,XmlNode section)
      {
         int iLevel = 0;
         string sName = "";

         ConfigHelper.GetEnumValue(section, "level", typeof(LevelSetting), ref iLevel);
         ConfigHelper.GetStringValue(section,"name",ref sName);
         return new MyConfigSection((LevelSetting)iLevel,sName);
      }
   }
   public class MyConfigSection
   {
      private LevelSetting level = LevelSetting.None;
      private string name = null;
      
      public MyConfigSection(LevelSetting _level,string _name)
      {
         level = _level;
         name = _name;
      }
      public LevelSetting Level
      {
         get {return level;}
      }
      public string Name
      {
         get {return name;}
      }
   }
   internal class ConfigHelper
   {
      public static XmlNode GetEnumValue
      (XmlNode _node, string _attribute,Type _enumType, ref int _val)
      {
         XmlNode a = _node.Attributes.RemoveNamedItem(_attribute);
         if(a==null)
            throw new ConfigurationException("Attribute required: " + _attribute);
         if(Enum.IsDefined(_enumType, a.Value))
            _val = (int)Enum.Parse(_enumType,a.Value);
         else
            throw new ConfigurationException("Invalid Level",a);
         return a;
      }
      public static XmlNode GetStringValue(XmlNode _node, string _attribute, ref string _val)
      {
         XmlNode a = _node.Attributes.RemoveNamedItem(_attribute);
         if(a==null)
            throw new ConfigurationException("Attribute required: " + _attribute);
         else
            _val = a.Value;
         return a;
      }
   }
}
在Web.config增加：<configSections>
   <sectionGroup name="system.web">
      <section name="myConfig" type="MyConfig.MyConfigSectionHandler,MyConfig" />
   </sectionGroup>
</configSections>

<system.web>
<myConfig level="High" name="hello world" />
</system.web>WebForm1.aspx.cs:using MyConfig;MyConfigSection s = (MyConfigSection)Context.GetConfig("system.web/myConfig");
Response.Write("Level: " + s.Level + "<br>");
Response.Write("Name: " + s.Name);