.NET：自定义配置节

背景

对于编译型应用程序来说，参数化程序行为是非常有必要的，.NET有其标准的配置方法，我们可以可以扩展。

示例

代码

using System;
using System.Collections;
using System.Text;
using System.Configuration;
using System.Xml;

namespace YEA.Infrastructure.Gateway.Config
{
    public enum ExchangeType { direct, topic, fanout };
    public class Exchange : ConfigurationElement
    {
        [ConfigurationProperty("name", DefaultValue = "", IsRequired = true)]
        public string Name
        {
            get { return (string) this["name"]; }
            set { this["name"] = value; }
        }
        [ConfigurationProperty("connection", DefaultValue = "", IsRequired = true)]
        public string Connection
        {
            get { return (string)this["connection"]; }
            set { this["connection"] = value; }
        }
        [ConfigurationProperty("type", DefaultValue = "direct", IsRequired = true)]
        public ExchangeType Type
        {
            get { return (ExchangeType)this["type"]; }
            set { this["type"] = value; }
        }
        [ConfigurationProperty("autodelete", DefaultValue= true, IsRequired = false)]
        public bool AutoDelete
        {
            get { return (bool)this["autodelete"]; }
            set { this["autodelete"] = value; }
        }
        [ConfigurationProperty("durable", DefaultValue = false, IsRequired = false)]
        public bool Durable
        {
            get { return (bool)this["durable"]; }
            set { this["durable"] = value; }
        }
    }
    public class ExchangeCollection : ConfigurationElementCollection
    {
        public override ConfigurationElementCollectionType CollectionType
        {
            get
            {
                return ConfigurationElementCollectionType.AddRemoveClearMap;
            }
        }
        protected override ConfigurationElement CreateNewElement()
        {
            return new Exchange();
        }
        protected override object GetElementKey(ConfigurationElement element)
        {
            return ((Exchange)element).Name;
        }
        public new string AddElementName
        {
            get { return base.AddElementName; }
            set { base.AddElementName = value; }
        }
        public new string ClearElementName
        {
            get { return base.ClearElementName; }
            set { base.ClearElementName = value; }

        }

        public new string RemoveElementName
        {
            get { return base.RemoveElementName; }
        }

        public new int Count
        {
            get { return base.Count; }
        }


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

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

        public int IndexOf(Exchange exchange)
        {
            return BaseIndexOf(exchange);
        }

        public void Add(Exchange exchange)
        {
            BaseAdd(exchange);
            // Add custom code here.
        }

        protected override void BaseAdd(ConfigurationElement element)
        {
            BaseAdd(element, false);
            // Add custom code here.
        }

        public void Remove(Exchange exchange)
        {
            if (BaseIndexOf(exchange) >= 0)
                BaseRemove(exchange.Name);
        }

        public void RemoveAt(int index)
        {
            BaseRemoveAt(index);
        }

        public void Remove(string name)
        {
            BaseRemove(name);
        }

        public void Clear()
        {
            BaseClear();
            // Add custom code here.
        }
    }
    public class AMQPObjectsDeclarationSection : ConfigurationSection
    {
        [ConfigurationProperty("ExchangeList", IsDefaultCollection = false)]
        public ExchangeCollection ExchangeList
        {
            get
            {
                ExchangeCollection exchanges = (ExchangeCollection)this["ExchangeList"];
                return exchanges;
            }
        }
        [ConfigurationProperty("QueueList", IsDefaultCollection = false)]
        public QueueCollection QueueList
        {
            get
            {
                QueueCollection queue = (QueueCollection)this["QueueList"];
                return queue;
            }
        }
        [ConfigurationProperty("BindingList", IsDefaultCollection = false)]
        public BindingCollection BindingList
        {
            get
            {
                BindingCollection binding = (BindingCollection)this["BindingList"];
                return binding;
            }
        }

        protected override void DeserializeSection(System.Xml.XmlReader reader)
        {
            base.DeserializeSection(reader);
            // You can add custom processing code here.
        }

        protected override string SerializeSection(
            ConfigurationElement parentElement,
            string name, ConfigurationSaveMode saveMode)
        {
            string s =
                base.SerializeSection(parentElement,
                name, saveMode);
            // You can add custom processing code here.
            return s;
        }

    }
}

最终XML配置

App.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <sectionGroup name="AMQPConnection">
      <section name="ConnectionSettings"
                     type="YEA.Infrastructure.Gateway.Config.ConnectionSection, YEA.Infrastructure.Gateway"></section>
    </sectionGroup>
    <sectionGroup name="AMQPAdmin">
      <section name="AMQPObjectsDeclaration"
               type="YEA.Infrastructure.Gateway.Config.AMQPObjectsDeclarationSection, YEA.Infrastructure.Gateway"
               allowLocation="true"
               allowDefinition="Everywhere"></section>
    </sectionGroup>

  </configSections>
  <AMQPConnection >
    <ConnectionSettings configSource="Config\amqp.connection.config"/>
  </AMQPConnection>
  <AMQPAdmin>
    <AMQPObjectsDeclaration configSource="Config\amqp.objects.config"/>
  </AMQPAdmin>
  <appSettings >
    <add key="SleepTime" value="0"></add>
    <!--Mode = ["Receiver","Transmitter"]-->
    <add key="Mode" value="Receiver"></add>
    <add key="DummyFile" value="C:\logs\YEA\Monitor\LogService.txt"></add>
    <add key="notificationToEmail" value="ruben.rotteveel@chamberlain.com"/>
    <add key="notificationFromEmail" value="webmaster@chamberlain.com"/>
  </appSettings>
</configuration>

amqp.connection.config

<?xml version="1.0" encoding="utf-8" ?>
<ConnectionSettings>
  <ConnectionList>
    <add name="Connection" server="localhost" username="guest" password="guest"></add>  
  </ConnectionList>
  <PublisherList>
    <add name="orderPublisher" connection="Connection" exchange="orders" ></add>
    <add name="notificationPublisher" connection="Connection" exchange="notificationExchange"></add>
    <add name="logPublisher" connection="Connection" exchange="logExchange"></add>
  </PublisherList>
  <AsyncReceiverList>
    <add name="orderReceiver" connection="Connection" queue="uk_orders, marketingemails, Accounting, CustomerService" maxthreads="40"></add>
    <add name="notificationReceiver" connection="Connection" queue="notificationQueue" maxthreads ="1"></add>
    <add name="logReceiver" connection="Connection" queue="logQueue" maxthreads ="1"></add>
  </AsyncReceiverList>
</ConnectionSettings>

amqp.objects.config

<?xml version="1.0" encoding="utf-8" ?>
<AMQPObjectsDeclaration>
  <ExchangeList>
    <add name="orders" connection="Connection" type="topic" autodelete="false" durable="true"></add>
    <add name="shipments" connection="Connection" type ="topic" autodelete="false" durable="true"></add>
    <add name="logExchange" connection="Connection" type="topic" autodelete="false" durable="true"></add>
    <add name="notificationExchange" connection="Connection" type="topic" autodelete="false" durable="true"></add>
  </ExchangeList>
  <QueueList>
    <add name="uk_orders" connection="Connection" autodelete="false" durable="true"></add>
    <add name="us_orders" connection="Connection" autodelete="false" durable="true"></add>
    <add name="marketingemails" connection="Connection" autodelete ="false" durable="true"></add>
    <add name="Accounting" connection="Connection" autodelete="false" durable="true" ></add>
    <add name="CustomerService" connection="Connection" autodelete="false" durable="true" ></add>
    <add name="logQueue" connection="Connection" autodelete="false" durable="true"></add>
    <add name="notificationQueue" connection="Connection" autodelete="false" durable="true"></add>
  </QueueList>
  <BindingList>
    <add queue="uk_orders" connection="Connection" exchange="orders" subscriptionkey="order.uk.#"></add>
    <add queue="us_orders" connection="Connection" exchange="orders" subscriptionkey="order.us.#"></add>
    <add queue="marketingemails" connection="Connection" exchange="shipments" subscriptionkey="#" ></add>
    <add queue="marketingemails" connection="Connection" exchange="orders" subscriptionkey="#" ></add>
    <add queue="Accounting" connection="Connection" exchange="shipments" subscriptionkey="#" ></add>
    <add queue="Accounting" connection="Connection" exchange="orders" subscriptionkey="#" ></add>
    <add queue="CustomerService" connection="Connection" exchange="shipments" subscriptionkey="#" ></add>
    <add queue="CustomerService" connection="Connection" exchange="orders" subscriptionkey="#" ></add>
    <add queue="logQueue" connection="Connection" exchange="logExchange" subscriptionkey="#"></add>
    <add queue="notificationQueue" connection="Connection" exchange="notificationExchange" subscriptionkey="#"></add>
  </BindingList>
</AMQPObjectsDeclaration>

读取配置

            var config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
            var objects = config.GetSection("AMQPAdmin/AMQPObjectsDeclaration") as AMQPObjectsDeclarationSection;

备注

简单的使用配置并不是最好的方式，比如：在控制台程序中，最好提供两种方式：通过命令行参数和配置结合，然后采用适当的优先级处理。另外，采用JSON配置可能会更简单一点。