自定义ConfigurationSection，创建多个嵌套的ConfigurationElementCollection节点

由于接口地址都是固定的，所以想到使用自定义节点，来将接口都配置到web.config中。

很快，v1.0版本出炉:　

public class RequestConfigSection : ConfigurationSection
    {
        [ConfigurationProperty("sources", IsDefaultCollection = true)]
        [ConfigurationCollection(typeof(RequestConfigSourceCollection), AddItemName = "add")]
        public RequestConfigSourceCollection ConfigCollection
        {
            get { return (RequestConfigSourceCollection)this["sources"]; }
            set { this["sources"] = value; }
        }
    }
    
    public class RequestConfigSourceCollection : ConfigurationElementCollection
    {
        /// <summary>
        /// 创建新元素
        /// </summary>
        /// <returns></returns>
        protected override ConfigurationElement CreateNewElement()
        {
            return new RequestConfigSource();
        }

        /// <summary>
        /// 获取元素的键
        /// </summary>
        /// <param name="element"></param>
        /// <returns></returns>
        protected override object GetElementKey(ConfigurationElement element)
        {
            return ((RequestConfigSource)element).Name;
        }

        /// <summary>
        /// 获取所有键
        /// </summary>
        public IEnumerable<string> AllKeys { get { return BaseGetAllKeys().Cast<string>(); } }

        /// <summary>
        /// 索引器
        /// </summary>
        /// <param name="name"></param>
        /// <returns></returns>
        public new RequestConfigSource this[string name]
        {
            get { return (RequestConfigSource)BaseGet(name); }
        }
    }

    public class RequestConfigSource : ConfigurationElement
    {
        /// <summary>
        /// 名称
        /// </summary>
        [ConfigurationProperty("name")]
        public string Name
        {
            get { return (string)this["name"]; }
            set { this["name"] = value; }
        }

        /// <summary>
        /// 地址
        /// </summary>
        [ConfigurationProperty("url")]
        public string Url
        {
            get { return (string)this["url"]; }
            set { this["url"] = value; }
        }

        /// <summary>
        /// 访问类型
        /// </summary>
        [ConfigurationProperty("type")]
        public RequestType RequestType
        {
            get
            {
                return (RequestType)Enum.Parse(typeof(RequestType), this["type"].ToString(), true);
            }
            set { this["type"] = value; }
        }
    }

在web.config中的配置方式为:

<apiRequestConfig>
  <sources>
    <add name="..." url="..." type="POST" />
    <add name="..." url="..." type="POST" />
    <add name="..." url="..." type="POST" />
  </sources>
</apiRequestConfig>

 这时候又看了一遍需求文档，发现有说明不同平台的接口地址是不一样的，但接口做的事情是一样的。

然后就开始想，如果接着在下边追加，则不同平台的同一接口的名称是不能相同的。

所以想到的理想的配置方式为:

<apiRequestConfig>
  <sources platform="android">
    <add name="..." url="..." type="POST" />
    <add name="..." url="..." type="POST" />
    <add name="..." url="..." type="POST" />
  </sources>
  <sources platform="ios">
    <add name="..." url="..." type="POST" />
    <add name="..." url="..." type="POST" />
    <add name="..." url="..." type="POST" />
  </sources>
</apiRequestConfig>

 但是sources 名称的节点只能出现一次…好吧，蛋疼了。

研究尝试了一上午也没有找到合适的解决方式，又懒得再重新写一套代码来读取XML，…开始在网上搜解决方案

用中文做关键字找不着…翻了墙，用英文来当关键字 one or more ConfigurationElementCollection…

最终在一老外的博客里找到了一个替代的解决方案，最终的配置为：

<apiRequestConfig>
    <requestConfigs>
      <request platform="android">
        <sources>
          <add name="..." url="..." type="POST" />
          <add name="..." url="..." type="POST" />
          <add name="..." url="..." type="POST" />
        </sources>
      </request>
      <request platform="ios">
        <sources>
          <add name="..." url="..." type="POST" />
          <add name="..." url="..." type="POST" />
          <add name="..." url="..." type="POST" />
        </sources>
      </request>
    </requestConfigs>
  </apiRequestConfig>

C#代码如下：

public class RequestConfigSection : ConfigurationSection
    {
        [ConfigurationProperty("requestConfigs", IsDefaultCollection = true)]
        [ConfigurationCollection(typeof(RequestConfigTypeCollection), AddItemName = "request")]
        public RequestConfigTypeCollection ConfigCollection
        {
            get { return (RequestConfigTypeCollection)this["requestConfigs"]; }
            set { this["requestConfigs"] = value; }
        }

        /// <summary>
        /// 根据平台和名称获取请求配置信息
        /// </summary>
        /// <param name="name"></param>
        /// <param name="platform"></param>
        /// <returns></returns>
        public RequestConfigSource GetRequestConfigSource(string platform, string name)
        {
            return ConfigCollection[platform].SourceCollection[name];
        }
    }

    public class RequestConfigTypeCollection : ConfigurationElementCollection
    {
        /// <summary>
        /// 创建新元素
        /// </summary>
        /// <returns></returns>
        protected override ConfigurationElement CreateNewElement()
        {
            return new RequestConfigType();
        }

        /// <summary>
        /// 获取元素的键
        /// </summary>
        /// <param name="element"></param>
        /// <returns></returns>
        protected override object GetElementKey(ConfigurationElement element)
        {
            return ((RequestConfigType)element).Platform;
        }

        /// <summary>
        /// 获取所有键
        /// </summary>
        public IEnumerable<string> AllKeys { get { return BaseGetAllKeys().Cast<string>(); } }

        /// <summary>
        /// 索引器
        /// </summary>
        /// <param name="name"></param>
        /// <returns></returns>
        public new RequestConfigType this[string platform]
        {
            get { return (RequestConfigType)BaseGet(platform); }
        }
    }

    public class RequestConfigType : ConfigurationElement
    {
        /// <summary>
        /// 获取全部请求配置信息
        /// </summary>
        /// <returns></returns>
        public RequestConfigSource[] GetAllRequestSource()
        {
            var keys = this.SourceCollection.AllKeys;

            return keys.Select(name => this.SourceCollection[name]).ToArray();
        }
        /// <summary>
        /// 平台标识
        /// </summary>
        [ConfigurationProperty("platform")]
        public string Platform
        {
            get { return (string)this["platform"]; }
            set { this["platform"] = value; }
        }

        [ConfigurationProperty("sources", IsDefaultCollection = true)]
        [ConfigurationCollection(typeof(RequestConfigSourceCollection), AddItemName = "add")]
        public RequestConfigSourceCollection SourceCollection
        {
            get { return (RequestConfigSourceCollection)this["sources"]; }
            set { this["sources"] = value; }
        }
    }

    public class RequestConfigSourceCollection : ConfigurationElementCollection
    {
        /// <summary>
        /// 创建新元素
        /// </summary>
        /// <returns></returns>
        protected override ConfigurationElement CreateNewElement()
        {
            return new RequestConfigSource();
        }

        /// <summary>
        /// 获取元素的键
        /// </summary>
        /// <param name="element"></param>
        /// <returns></returns>
        protected override object GetElementKey(ConfigurationElement element)
        {
            return ((RequestConfigSource)element).Name;
        }

        /// <summary>
        /// 获取所有键
        /// </summary>
        public IEnumerable<string> AllKeys { get { return BaseGetAllKeys().Cast<string>(); } }

        /// <summary>
        /// 索引器
        /// </summary>
        /// <param name="name"></param>
        /// <returns></returns>
        public new RequestConfigSource this[string name]
        {
            get { return (RequestConfigSource)BaseGet(name); }
        }
    }

    /// <summary>
    /// 请求的配置信息
    /// </summary>
    public class RequestConfigSource : ConfigurationElement
    {
        /// <summary>
        /// 名称
        /// </summary>
        [ConfigurationProperty("name")]
        public string Name
        {
            get { return (string)this["name"]; }
            set { this["name"] = value; }
        }

        /// <summary>
        /// 地址
        /// </summary>
        [ConfigurationProperty("url")]
        public string Url
        {
            get { return (string)this["url"]; }
            set { this["url"] = value; }
        }

        /// <summary>
        /// 访问类型
        /// </summary>
        [ConfigurationProperty("type")]
        public RequestType RequestType
        {
            get
            {
                return (RequestType)Enum.Parse(typeof(RequestType), this["type"].ToString(), true);
            }
            set { this["type"] = value; }
        }
    }

本人的开发环境为 .net framework 4.0

最初RequestConfigSection 类中的ConfigCollection 和  RequestConfigType 类中的SourceCollection  没有定义ConfigurationCollection特性

而是在RequestConfigTypeCollection和RequestConfigTypeCollection 中重载了ElementName属性，返回子级的节点名。

结果抛出节点名未定义的异常…

改由特性ConfigurationCollection定义，并给特性属性AddItemName赋值为子级的节点名 解决…