ConfigurationSectionGroupCollection Class

using System;
using System.Configuration;
using System.Collections;

namespace Samples.Config
{


    // Define a custom section. 
    public sealed class CustomSection :
        ConfigurationSection
    {

        public CustomSection()
        { }

        [ConfigurationProperty("fileName", DefaultValue = "default.txt",
            IsRequired = true, IsKey = false)]
        [StringValidator(InvalidCharacters = " ~!@#$%^&*()[]{}/;'\"|\\",
            MinLength = 1, MaxLength = 60)]
        public string FileName
        {
            get
            {
                return (string)this["fileName"];
            }
            set
            {
                this["fileName"] = value;
            }
        }

        [ConfigurationProperty("maxUsers", DefaultValue = (long)10000,
            IsRequired = false)]
        [LongValidator(MinValue = 1, MaxValue = 10000000,
            ExcludeRange = false)]
        public long MaxUsers
        {
            get
            {
                return (long)this["maxUsers"];
            }
            set
            {
                this["maxUsers"] = value;
            }
        }

        [ConfigurationProperty("maxIdleTime",
            DefaultValue = "0:10:0",
            IsRequired = false)]
        [TimeSpanValidator(MinValueString = "0:0:30",
            MaxValueString = "5:00:0",
            ExcludeRange = false)]
        public TimeSpan MaxIdleTime
        {
            get
            {
                return (TimeSpan)this["maxIdleTime"];
            }
            set
            {
                this["maxIdleTime"] = value;
            }
        }

    }

    // Define a custom section group. 
    public sealed class CustomSectionGroup :
        ConfigurationSectionGroup
    {

        public CustomSectionGroup()
        {

        }

        public CustomSection Custom
        {
            get { return (CustomSection) 
                Sections.Get("CustomSection");}
        }

    }

    class UsingCustomSectionGroupCollection
    {


        // Create a custom section group. 
        static void CreateSectionGroup()
        {
            try
            {

                CustomSectionGroup customSectionGroup;

                // Get the current configuration file.
                System.Configuration.Configuration config =
                        ConfigurationManager.OpenExeConfiguration(
                        ConfigurationUserLevel.None);

                // Create the section group entry   
                // in the <configSections> and the  
                // related target section in <configuration>. 
                if (config.SectionGroups["CustomGroup"] == null)
                {
                    customSectionGroup = new CustomSectionGroup();
                    config.SectionGroups.Add("CustomGroup", 
                        customSectionGroup);
                    customSectionGroup.ForceDeclaration(true);
                    config.Save(ConfigurationSaveMode.Full);
                }

            }
            catch (ConfigurationErrorsException err)
            {
                Console.WriteLine(err.ToString());
            }

        }

        // Get the collection group keys i.e., 
        // the group names. 
        //static void GetAllKeys() 
        //{ 

        //    try 
        //    { 
        //        System.Configuration.Configuration config = 
        //        ConfigurationManager.OpenExeConfiguration( 
        //        ConfigurationUserLevel.None); 

        //        ConfigurationSectionGroupCollection groups = 
        //            config.SectionGroups; 
        //        groups. 
        //        foreach (string name in groups.AllKeys) 
        //        { 
        //            Console.WriteLine( 
        //             "Key value: {0}", name);
        //        } 


        //    } 
        //    catch (ConfigurationErrorsException err) 
        //    { 
        //        Console.WriteLine(err.ToString()); 
        //    } 
        //} 

        static void Clear()
        {

            try
            {
                System.Configuration.Configuration config =
                ConfigurationManager.OpenExeConfiguration(
                ConfigurationUserLevel.None);

                config.SectionGroups.Clear();

                config.Save(ConfigurationSaveMode.Full);
            }
            catch (ConfigurationErrorsException err)
            {
                Console.WriteLine(err.ToString());
            }
        }

        static void GetGroup()
        {

            try
            {
                System.Configuration.Configuration config =
                ConfigurationManager.OpenExeConfiguration(
                ConfigurationUserLevel.None);

                ConfigurationSectionGroup customGroup =
                    config.SectionGroups.Get("CustomGroup");


                if (customGroup == null)
                    Console.WriteLine(
                        "Failed to load CustomSection.");
                else
                {
                    // Display section information
                    Console.WriteLine("Section group name:       {0}",
                        customGroup.SectionGroupName);
                    Console.WriteLine("Name:       {0}",
                        customGroup.Name);
                    Console.WriteLine("Type:   {0}",
                        customGroup.Type);

                }

            }
            catch (ConfigurationErrorsException err)
            {
                Console.WriteLine(err.ToString());
            }
        }

        static void GetEnumerator()
        {

            try
            {
                System.Configuration.Configuration config =
                ConfigurationManager.OpenExeConfiguration(
                ConfigurationUserLevel.None);

                ConfigurationSectionGroupCollection groups =
                    config.SectionGroups;

                IEnumerator groupEnum =
                    groups.GetEnumerator();

                int i = 0;
                while (groupEnum.MoveNext())
                {
                    string groupName = groups.GetKey(i);
                    Console.WriteLine(
                        "Group name: {0}", groupName);
                    i += 1;
                }
            }
            catch (ConfigurationErrorsException err)
            {
                Console.WriteLine(err.ToString());
            }
        }


        // Get the collection keys i.e., the 
        // group names. 
        static void GetKeys()
        {

            try
            {
                System.Configuration.Configuration config =
                ConfigurationManager.OpenExeConfiguration(
                ConfigurationUserLevel.None);

                ConfigurationSectionGroupCollection groups =
                    config.SectionGroups;

                foreach (string key in groups.Keys)
                {

                    Console.WriteLine(
                     "Key value: {0}", key);
                }


            }
            catch (ConfigurationErrorsException err)
            {
                Console.WriteLine(err.ToString());
            }
        }


        static void GetItems()
        {

            try
            {
                System.Configuration.Configuration config =
                 ConfigurationManager.OpenExeConfiguration(
                 ConfigurationUserLevel.None);

                ConfigurationSectionGroupCollection groups =
                    config.SectionGroups;

                ConfigurationSectionGroup group1 =
                    groups.Get("system.net");

                ConfigurationSectionGroup group2 =
                groups.Get("system.web");


                Console.WriteLine(
                     "Group1: {0}", group1.Name);

                Console.WriteLine(
                    "Group2: {0}", group2.Name);

            }
            catch (ConfigurationErrorsException err)
            {
                Console.WriteLine(err.ToString());
            }
        }


        static void Remove()
        {

            try
            {

                System.Configuration.Configuration config =
                    ConfigurationManager.OpenExeConfiguration(
                   ConfigurationUserLevel.None);

                ConfigurationSectionGroup customGroup =
                    config.SectionGroups.Get("CustomGroup");

                if (customGroup != null)
                {
                    config.SectionGroups.Remove("CustomGroup");
                    config.Save(ConfigurationSaveMode.Full);
                }
                else
                    Console.WriteLine(
                        "CustomGroup does not exists.");

            }
            catch (ConfigurationErrorsException err)
            {
                Console.WriteLine(err.ToString());
            }
        }



        // Add custom section to the group. 
        static void AddSection()
        {
            try
            {

                CustomSection customSection;

                // Get the current configuration file.
                System.Configuration.Configuration config =
                        ConfigurationManager.OpenExeConfiguration(
                        ConfigurationUserLevel.None);

                // Create the section entry   
                // in the <configSections> and the  
                // related target section in <configuration>.
                ConfigurationSectionGroup customGroup;
                customGroup = config.SectionGroups.Get("CustomGroup");

                if (customGroup.Sections.Get("CustomSection") == null)
                {
                    customSection = new CustomSection();
                    customGroup.Sections.Add("CustomSection",
                        customSection);
                    customSection.SectionInformation.ForceSave = true;
                    config.Save(ConfigurationSaveMode.Full);
                }
            }
            catch (ConfigurationErrorsException err)
            {
                Console.WriteLine(err.ToString());
            }

        }

        // Exercise the collection. 
        // Uncomment the function you want to exercise. 
        // Start with CreateSectionGroup(). 
        static void Main(string[] args)
        {
            CreateSectionGroup();
            AddSection();
            // GetAllKeys(); 
            // GetGroup(); 

            // GetEnumerator(); 

            // GetKeys(); 

            // GetItems(); 

            // Remove(); 
            // Clear();
        }


    }
}