自定义App.config NameValueSectionHandler的bug修复创建自己的NameValueCollectionSectionHandler...

在很多时候我们需要自定义我们自己的自定义App.config 文件，而微软为我们提供了默认的

      System.Configuration.NameValueSectionHandler
      System.Configuration.DictionarySectionHandler
      System.Configuration.SingleTagSectionHandler

经常用这些也没有出现问题。今天因项目需求的问题再次使用System.Configuration.NameValueSectionHandler，相应的配置如下：

<configSections>
    <section name="mySection1"  type="System.Configuration.NameValueSectionHandler, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
  </configSections>
  <mySection1>
    <add key="filepath" value="Views/Channel/men"></add>
    <add key="filepath" value="Views/Channel/homme"></add>
    <add key="filepath" value="Views/Channel/fleece/20120906"></add>
    <add key="filepath" value="Views/Channel/Designer"></add>
    <add key="filepath" value="Views/Channel/coats/20120816"></add>
    <add key="filepath" value="Views/Channel/xiuxianku/20120517"></add>
    <add key="filepath" value="men"></add>
    <add key="filepath" value="homme"></add>
    <add key="filepath" value="fleece"></add>
    <add key="filepath" value="Designer"></add>
    <add key="filepath" value="coats"></add>
    <add key="filepath" value="xiuxianku"></add>
  </mySection1>

 然后在读取相应的配置信息。

         NameValueCollection mySection1 = ((NameValueCollection)ConfigurationManager.GetSection("mySection1"));
            List<string> fileList = mySection1["filepath"].Split(new char[] { ',' }).ToList();

 得到的结果只有最后一条，而我们所用的NameValueCollection不一致，让我们来看看源码吧：

internal static object CreateStatic(object parent, XmlNode section, string keyAttriuteName, string valueAttributeName)
{
    ReadOnlyNameValueCollection values;
    if (parent == null)
    {
        values = new ReadOnlyNameValueCollection(StringComparer.OrdinalIgnoreCase);
    }
    else
    {
        ReadOnlyNameValueCollection values2 = (ReadOnlyNameValueCollection) parent;
        values = new ReadOnlyNameValueCollection(values2);
    }
    HandlerBase.CheckForUnrecognizedAttributes(section);
    foreach (XmlNode node in section.ChildNodes)
    {
        if (!HandlerBase.IsIgnorableAlsoCheckForNonElement(node))
        {
            if (node.Name == "add")
            {
                string str = HandlerBase.RemoveRequiredAttribute(node, keyAttriuteName);
                string str2 = HandlerBase.RemoveRequiredAttribute(node, valueAttributeName, true);
                HandlerBase.CheckForUnrecognizedAttributes(node);
                values[str] = str2;
            }
            else if (node.Name == "remove")
            {
                string name = HandlerBase.RemoveRequiredAttribute(node, keyAttriuteName);
                HandlerBase.CheckForUnrecognizedAttributes(node);
                values.Remove(name);
            }
            else if (node.Name.Equals("clear"))
            {
                HandlerBase.CheckForUnrecognizedAttributes(node);
                values.Clear();
            }
            else
            {
                HandlerBase.ThrowUnrecognizedElement(node);
            }
        }
    }
    values.SetReadOnly();
    return values;
}

 很明显在add的时候它用的是values[str] = str2;而不是调用add方法。

修改后代码：

  public class NameValueCollectionSectionHandler : IConfigurationSectionHandler
    {
        // Fields
        private const string defaultKeyAttribute = "key";
        private const string defaultValueAttribute = "value";

        // Methods
        public object Create(object parent, object context, XmlNode section)
        {
            return CreateStatic(parent, section, this.KeyAttributeName, this.ValueAttributeName);
        }

        internal static object CreateStatic(object parent, XmlNode section)
        {
            return CreateStatic(parent, section, "key", "value");
        }

        internal static object CreateStatic(object parent, XmlNode section, string keyAttriuteName, string valueAttributeName)
        {
            NameValueCollection values;
            if (parent == null)
            {
                values = new NameValueCollection(StringComparer.OrdinalIgnoreCase);
            }
            else
            {
                NameValueCollection values2 = (NameValueCollection)parent;
                values = new NameValueCollection(values2);
            }

            foreach (XmlNode node in section.ChildNodes)
            {
                if (node.Name == "add")
                {
                    string key = node.Attributes[keyAttriuteName].Value;
                    string value = node.Attributes[valueAttributeName].Value;
                    values.Add(key, value);
                }
                else if (node.Name == "remove")
                {
                    string key = node.Attributes[keyAttriuteName].Value;
                    values.Remove(key);
                }
                else if (node.Name.Equals("clear"))
                {
                    values.Clear();
                }
            }
            return values;
        }

        // Properties
        protected virtual string KeyAttributeName
        {
            get
            {
                return "key";
            }
        }

        protected virtual string ValueAttributeName
        {
            get
            {
                return "value";
            }
        }
    }

当然这样运行结果就和我们常用的NameValueCollection一样。