//引入命名空间
using System;
using System.Configuration;

// Define a UrlsSection custom section that contains a 
// UrlsCollection collection of UrlConfigElement elements.
public class UrlsSection : ConfigurationSection
{

    // Declare the UrlsCollection collection property.
    [ConfigurationProperty("urls", IsDefaultCollection = false)]
    [ConfigurationCollection(typeof(UrlsCollection),
        AddItemName = "add",
        ClearItemsName = "clear",
        RemoveItemName = "remove")]
    public UrlsCollection Urls
    {
        get
        {
            UrlsCollection urlsCollection =
                (UrlsCollection)base["urls"];

            return urlsCollection;
        }

        set
        {
            UrlsCollection urlsCollection = value;
        }
    }

    // Create a new instance of the UrlsSection.
    // This constructor creates a configuration element 
    // using the UrlConfigElement default values.
    // It assigns this element to the collection.
    public UrlsSection()
    {
        UrlConfigElement url = new UrlConfigElement();
        Urls.Add(url);
    }
}

// Define the UrlsCollection that contains the 
// UrlsConfigElement elements.
// This class shows how to use the ConfigurationElementCollection.
public class UrlsCollection : ConfigurationElementCollection
{

    public UrlsCollection()
    {
    }

    public override ConfigurationElementCollectionType CollectionType
    {
        get
        {
            return ConfigurationElementCollectionType.AddRemoveClearMap;
        }
    }

    protected override ConfigurationElement CreateNewElement()
    {
        return new UrlConfigElement();
    }

    protected override Object GetElementKey(ConfigurationElement element)
    {
        return ((UrlConfigElement)element).Name;
    }

    public UrlConfigElement this[int index]
    {
        get
        {
            return (UrlConfigElement)BaseGet(index);
        }
        set
        {
            if (BaseGet(index) != null)
            {
                BaseRemoveAt(index);
            }
            BaseAdd(index, value);
        }
    }

    new public UrlConfigElement this[string Name]
    {
        get
        {
            return (UrlConfigElement)BaseGet(Name);
        }
    }

    public int IndexOf(UrlConfigElement url)
    {
        return BaseIndexOf(url);
    }

    public void Add(UrlConfigElement url)
    {
        BaseAdd(url);

        // Your custom code goes here.
    }

    protected override void BaseAdd(ConfigurationElement element)
    {
        BaseAdd(element, false);

        // Your custom code goes here.
    }
    
    public void Remove(UrlConfigElement url)
    {
        if (BaseIndexOf(url) >= 0)
        {
            BaseRemove(url.Name);
            // Your custom code goes here.
            Console.WriteLine("UrlsCollection: {0}", "Removed collection element!");
        }
    }
    
    public void RemoveAt(int index)
    {
        BaseRemoveAt(index);

        // Your custom code goes here.
    }
    
    public void Remove(string name)
    {
        BaseRemove(name);

        // Your custom code goes here.
    }
    
    public void Clear()
    {
        BaseClear();

        // Your custom code goes here.
        Console.WriteLine("UrlsCollection: {0}", "Removed entire collection!");
    }
}

// Define the UrlsConfigElement elements that are contained 
// by the UrlsCollection.
public class UrlConfigElement : ConfigurationElement
{
    public UrlConfigElement(String name, String url, int port)
    {
        this.Name = name;
        this.Url = url;
        this.Port = port;
    }

    public UrlConfigElement()
    {
    }

    [ConfigurationProperty("name", DefaultValue = "Contoso",
        IsRequired = true, IsKey = true)]
    public string Name
    {
        get
        {
            return (string)this["name"];
        }
        set
        {
            this["name"] = value;
        }
    }

    [ConfigurationProperty("url", DefaultValue = "http://www.contoso.com",
        IsRequired = true)]
    [RegexStringValidator(@"\w+:\/\/[\w.]+\S*")]
    public string Url
    {
        get
        {
            return (string)this["url"];
        }
        set
        {
            this["url"] = value;
        }
    }
    
    [ConfigurationProperty("port", DefaultValue = (int)4040, IsRequired = false)]
    [IntegerValidator(MinValue = 0, MaxValue = 8080, ExcludeRange = false)]
    public int Port
    {
        get
        {
            return (int)this["port"];
        }
        set
        {
            this["port"] = value;
        }
    }
}

//引入命名空间
using System;
using System.Configuration;
using System.Text;

class UsingConfigurationCollectionElement
{

    // Create a custom section and save it in the 
    // application configuration file.
    static void CreateCustomSection()
    {
        try
        {

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

            // Add the custom section to the application
            // configuration file.
            UrlsSection myUrlsSection = (UrlsSection)config.Sections["MyUrls"];

            if (myUrlsSection == null)
            {
                //  The configuration file does not contain the
                // custom section yet. Create it.
                myUrlsSection = new UrlsSection();

                config.Sections.Add("MyUrls", myUrlsSection);

                // Save the application configuration file.
                myUrlsSection.SectionInformation.ForceSave = true;
                config.Save(ConfigurationSaveMode.Modified); 
            }
            else
                if (myUrlsSection.Urls.Count == 0)
                {

                    // The configuration file contains the
                    // custom section but its element collection is empty.
                    // Initialize the collection. 
                    UrlConfigElement url = new UrlConfigElement();
                    myUrlsSection.Urls.Add(url);

                    // Save the application configuration file.
                    myUrlsSection.SectionInformation.ForceSave = true;
                    config.Save(ConfigurationSaveMode.Modified);
                }

            Console.WriteLine("Created custom section in the application configuration file: {0}",
                config.FilePath);
            Console.WriteLine();
        }
        catch (ConfigurationErrorsException err)
        {
            Console.WriteLine("CreateCustomSection: {0}", err.ToString());
        }
    }

    static void ReadCustomSection()
    {
        try
        {
            // Get the application configuration file.
            System.Configuration.Configuration config =
                    ConfigurationManager.OpenExeConfiguration(
                    ConfigurationUserLevel.None) as Configuration;

            // Read and display the custom section.
            UrlsSection myUrlsSection =
               config.GetSection("MyUrls") as UrlsSection;

            if (myUrlsSection == null)
            {
                Console.WriteLine("Failed to load UrlsSection.");
            }
            else
            {
                Console.WriteLine("Collection elements contained in the custom section collection:");
                for (int i = 0; i < myUrlsSection.Urls.Count; i++)
                {
                    Console.WriteLine("   Name={0} URL={1} Port={2}",
                        myUrlsSection.Urls[i].Name,
                        myUrlsSection.Urls[i].Url,
                        myUrlsSection.Urls[i].Port);
                }
            }
        }
        catch (ConfigurationErrorsException err)
        {
            Console.WriteLine("ReadCustomSection(string): {0}", err.ToString());
        }
    }

    // Add an element to the custom section collection.
    // This function uses the ConfigurationCollectionElement Add method.
    static void AddCollectionElement()
    {
        try
        {

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

            // Get the custom configuration section.
            UrlsSection myUrlsSection = config.GetSection("MyUrls") as UrlsSection;

            // Add the element to the collection in the custom section.
            if (config.Sections["MyUrls"] != null)
            {
                UrlConfigElement urlElement = new UrlConfigElement();
                urlElement.Name = "Microsoft";
                urlElement.Url = "http://www.microsoft.com";
                urlElement.Port = 8080;
                
                // Use the ConfigurationCollectionElement Add method
                // to add the new element to the collection.
                myUrlsSection.Urls.Add(urlElement);

                // Save the application configuration file.
                myUrlsSection.SectionInformation.ForceSave = true;
                config.Save(ConfigurationSaveMode.Modified);

                Console.WriteLine("Added collection element to the custom section in the configuration file: {0}",
                    config.FilePath);
                Console.WriteLine();
            }
            else
            {
                Console.WriteLine("You must create the custom section first.");
            }
        }
        catch (ConfigurationErrorsException err)
        {
            Console.WriteLine("AddCollectionElement: {0}", err.ToString());
        }
    }

    // Remove element from the custom section collection.
    // This function uses one of the ConfigurationCollectionElement 
    // overloaded Remove methods.
    static void RemoveCollectionElement()
    {
        try
        {

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

            // Get the custom configuration section.
            UrlsSection myUrlsSection = config.GetSection("MyUrls") as UrlsSection;

            // Remove the element from the custom section.
            if (config.Sections["MyUrls"] != null)
            {
                UrlConfigElement urlElement = new UrlConfigElement();
                urlElement.Name = "Microsoft";
                urlElement.Url = "http://www.microsoft.com";
                urlElement.Port = 8080;

                // Use one of the ConfigurationCollectionElement Remove 
                // overloaded methods to remove the element from the collection.
                myUrlsSection.Urls.Remove(urlElement);

                // Save the application configuration file.
                myUrlsSection.SectionInformation.ForceSave = true;
                config.Save(ConfigurationSaveMode.Full);

                Console.WriteLine("Removed collection element from he custom section in the configuration file: {0}",
                    config.FilePath);
                Console.WriteLine();
            }
            else
            {
                Console.WriteLine("You must create the custom section first.");
            }
        }
        catch (ConfigurationErrorsException err)
        {
            Console.WriteLine("RemoveCollectionElement: {0}", err.ToString());
        }
    }

    // Remove the collection of elements from the custom section.
    // This function uses the ConfigurationCollectionElement Clear method.
    static void ClearCollectionElements()
    {
        try
        {

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

            // Get the custom configuration section.
            UrlsSection myUrlsSection = config.GetSection("MyUrls") as UrlsSection;

            // Remove the collection of elements from the section.
            if (config.Sections["MyUrls"] != null)
            {
                myUrlsSection.Urls.Clear();

                // Save the application configuration file.
                myUrlsSection.SectionInformation.ForceSave = true;
                config.Save(ConfigurationSaveMode.Full);

                Console.WriteLine("Removed collection of elements from he custom section in the configuration file: {0}",
                    config.FilePath);
                Console.WriteLine();
            }
            else
            {
                Console.WriteLine("You must create the custom section first.");
            }
        }
        catch (ConfigurationErrorsException err)
        {
            Console.WriteLine("ClearCollectionElements: {0}", err.ToString());
        }
    }

    public static void UserMenu()
    {
        string applicationName =
           Environment.GetCommandLineArgs()[0] + ".exe";
        StringBuilder buffer = new StringBuilder();

        buffer.AppendLine("Application: " + applicationName);
        buffer.AppendLine("Make your selection.");
        buffer.AppendLine("?    -- Display help.");
        buffer.AppendLine("Q,q  -- Exit the application.");
        buffer.Append("1    -- Create a custom section that");
        buffer.AppendLine(" contains a collection of elements.");
        buffer.Append("2    -- Read the custom section that");
        buffer.AppendLine(" contains a collection of custom elements.");
        buffer.Append("3    -- Add a collection element to");
        buffer.AppendLine(" the custom section.");
        buffer.Append("4    -- Remove a collection element from");
        buffer.AppendLine(" the custom section.");
        buffer.Append("5    -- Clear the collection of elements from");
        buffer.AppendLine(" the custom section.");
        
        Console.Write(buffer.ToString());
    }

    // Obtain user's input and provide
    // feedback.
    static void Main(string[] args)
    {
        // Define user selection string.
        string selection;

        // Get the name of the application.
        string appName =
          Environment.GetCommandLineArgs()[0];

        // Get user selection.
        while (true)
        {

            UserMenu();
            Console.Write("> ");
            selection = Console.ReadLine();
            if (!string.IsNullOrEmpty(selection))
                break;
        }

        while (selection.ToLower() != "q")
        {
            // Process user's input.
            switch (selection)
            {
                case "1":
                    // Create a custom section and save it in the 
                    // application configuration file.
                    CreateCustomSection();
                    break;

                case "2":
                    // Read the custom section from the
                    // application configuration file.
                    ReadCustomSection();
                    break;

                case "3":
                    // Add a collection element to the
                    // custom section.
                    AddCollectionElement();
                    break;

                case "4":
                    // Remove a collection element from the
                    // custom section.
                    RemoveCollectionElement();
                    break;

                case "5":
                    // Clear the collection of elements from the
                    // custom section.
                    ClearCollectionElements();
                    break;

                default:
                    UserMenu();
                    break;
            }
            Console.Write("> ");
            selection = Console.ReadLine();
        }
    }
}