自定义 ConfigurationSection,ConfigurationSectionGroup [web.config操作]

  public interface ICustomConfigurationGroup{}
    public interface ICustomConfigurationSection{} 

    public class CustomConfigurationGroup : ConfigurationSectionGroup, ICustomConfigurationGroup
    {       
    }

    public class CustomConfigurationSection : ConfigurationSection, ICustomConfigurationSection
    {
        [ConfigurationProperty("id")]
        public int Id
        {
            get { return (int)this["id"]; }
            set { this["id"] = value; }
        }
    
        [ConfigurationProperty("name")]
        public string Name
        {
            get { return (string)this["name"]; }
            set {  this["name"]= value; }
        }

        [ConfigurationProperty("time")]
        public DateTime Time
        {
            get { return (DateTime)this["time"]; }
            set { this["time"] = value; }
        }      
    }

    //http://msdn.microsoft.com/zh-cn/library/ms151451.aspx
    public class ConfigHelper
    {

        public static IEnumerable<T> GetConfigurationGroups<T>(string path) where T : ConfigurationSectionGroup,
                                                                                      ICustomConfigurationGroup
        {
            Configuration webconfig = GetConfiguration(CreateFileMap_Custom_Config, path);
            foreach (ConfigurationSectionGroup group in webconfig.SectionGroups)
                if (typeof(T).IsAssignableFrom(group.GetType()))
                {
                    yield return (T)group;
                }
        }

        public static IEnumerable<T> GetConfigurationSections<T>(ConfigurationSectionGroup sectionGroup) where 
                                                                                     T : ConfigurationSection, 
                                                                                         ICustomConfigurationSection
        {

            foreach (var section in sectionGroup.Sections)
                if (typeof(T).IsAssignableFrom(section.GetType()))
                {
                    yield return (T)section;
                }
        }


        //相对路径："/","/config"  不包含文件名.       
        public static Configuration GetConfiguration(Func<WebConfigurationFileMap> BuildFileMap,string path)
        {
            Configuration webconfig = WebConfigurationManager.OpenMappedWebConfiguration(BuildFileMap(), path);
            return webconfig;
        } 

        public static WebConfigurationFileMap CreateFileMap_Custom_Config()
        {
            WebConfigurationFileMap fileMap = new WebConfigurationFileMap();
            string physDir = System.Web.HttpContext.Current.Request.PhysicalApplicationPath;
            VirtualDirectoryMapping vDirMapBase = new VirtualDirectoryMapping(physDir, true, "web.config");
            fileMap.VirtualDirectories.Add("/", vDirMapBase);

            VirtualDirectoryMapping vDirMap = new VirtualDirectoryMapping(physDir + "config", false, "custom.config");
            fileMap.VirtualDirectories.Add("/config", vDirMap);

            vDirMap = new VirtualDirectoryMapping(physDir + "config\\app", false, "custom.config");
            fileMap.VirtualDirectories.Add("/config/app", vDirMap);
            vDirMap = new VirtualDirectoryMapping(physDir + "config\\cms", false, "custom.config");
            fileMap.VirtualDirectories.Add("/config/cms", vDirMap);


            return fileMap;
        } 
        public static WebConfigurationFileMap CreateFileMap_App_Config()
        {
            WebConfigurationFileMap fileMap = new WebConfigurationFileMap();
            string physDir = System.Web.HttpContext.Current.Request.PhysicalApplicationPath;
            VirtualDirectoryMapping vDirMapBase = new VirtualDirectoryMapping(physDir, true, "web.config");
            fileMap.VirtualDirectories.Add("/", vDirMapBase);

            VirtualDirectoryMapping vDirMap = new VirtualDirectoryMapping(physDir + "config", false, "app.config");
            fileMap.VirtualDirectories.Add("/config", vDirMap);

            vDirMap = new VirtualDirectoryMapping(physDir + "config\\app", false, "app.config");
            fileMap.VirtualDirectories.Add("/config/app", vDirMap);
            vDirMap = new VirtualDirectoryMapping(physDir + "config\\cms", false, "app.config");
            fileMap.VirtualDirectories.Add("/config/cms", vDirMap);


            return fileMap;
        }

    }

  public class ConfigUtil
        {

            public static void Create()
            {

                Configuration config = ConfigHelper.GetConfiguration(ConfigHelper.CreateFileMap_Custom_Config,"/config/app/");

                CustomConfigurationSection data = new CustomConfigurationSection();
                data.Id = 111;
                data.Name = "one";
                data.Time = DateTime.Now;

                config.SectionGroups.Add("group", new CustomConfigurationGroup());
                config.SectionGroups["group"].Sections.Add("add", data);



                config.Save(ConfigurationSaveMode.Minimal);
            }

            public static CustomConfigurationSection Read()
            {

                Configuration config = ConfigHelper.GetConfiguration(ConfigHelper.CreateFileMap_Custom_Config, "/config/app/");
                CustomConfigurationSection data = config.SectionGroups["group"].Sections["add"] as CustomConfigurationSection;

                return data;
            }

            public static void Delete()
            {
                Configuration config = ConfigHelper.GetConfiguration(ConfigHelper.CreateFileMap_Custom_Config,"/config/app/");
                //config.SectionGroups.Remove("group");
                if (config.SectionGroups["group"] != null)
                {
                    config.SectionGroups["group"].Sections.Remove("add");
                    //config.SectionGroups["group"].Sections.Clear();
                }
                config.Save(ConfigurationSaveMode.Minimal);
            }

            public static void Update()
            {
                Configuration config = ConfigHelper.GetConfiguration(ConfigHelper.CreateFileMap_Custom_Config,"/config/app/");
                
                var g = config.SectionGroups["group"];
                if (g == null)
                {
                    var gg = new CustomConfigurationGroup(); 
                    config.SectionGroups.Add("group", gg);
                }

                var s = config.SectionGroups["group"].SectionGroups["groupA"];
                if (s == null)
                {
                    var gg = new CustomConfigurationGroup();                  
                    config.SectionGroups["group"].SectionGroups.Add("groupA", gg);
                }
                var ss = config.SectionGroups["group"].SectionGroups["groupA"].Sections["ChildB"];
                if (ss == null)
                {  
                      CustomConfigurationSection data = new CustomConfigurationSection();
                      data.Id = 101;
                      data.Name = "wangwang";
                      data.Time = DateTime.Now;              
                    config.SectionGroups["group"].SectionGroups["groupA"].Sections.Add("ChildB", data);
                }

                config.Save(ConfigurationSaveMode.Minimal);
            }
        }

 public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            ConfigUtil.Create();
            ConfigUtil.Update();
        }
    }

<?xml version="1.0" encoding="utf-8"?>
<configuration>
    <configSections>
        <sectionGroup name="group" type="AppConfig.CustomConfigurationGroup, AppConfig, Version=1.0.0.0, 
                                                                                Culture=neutral, PublicKeyToken=null" >
            <section name="add" type="AppConfig.CustomConfigurationSection, AppConfig, Version=1.0.0.0, 
                                                                               Culture=neutral, PublicKeyToken=null" />
        </sectionGroup>
        <sectionGroup name="group">
            <sectionGroup name="groupA" type="AppConfig.CustomConfigurationGroup, AppConfig, Version=1.0.0.0,
                                                                                     Culture=neutral, PublicKeyToken=null" >
                <section name="ChildB" type="AppConfig.CustomConfigurationSection, AppConfig, Version=1.0.0.0, 
                                                                                      Culture=neutral, PublicKeyToken=null" />
            </sectionGroup>
        </sectionGroup>
    </configSections>
    <group>
        <add id="111" name="one" time="11/24/2012 22:43:53" />
        <groupA>
            <ChildB id="101" name="wangwang" time="11/24/2012 22:43:53" />
        </groupA>
    </group>
</configuration>

[注]:  http://msdn.microsoft.com/zh-cn/library/ms151451.aspx