config文件自定义节点

 

一： 目标

在app.config或者web.config中自定义节点，效果如下

<? xml version="1.0" encoding="utf-8"  ?>
< configuration >
   < configSections >
     < section  name ="DataBaseConfig"  type ="Configuration.Configuration.DataBaseConfigure,Configuration, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />
   </ configSections >
   < DataBaseConfig  DefaultConnectionString ="mahuiConnecting" >
     < ConnectionStrings >
       < add  name ="mahuiConnecting"   ConnectionString ="Connecting....1"   Provider ="Configuration.Implements.OleDBConnectingProvider,Configuration,Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" ></ add >
       < add  name ="XiaolinConnecting"   ConnectionString ="Connecting....2"   Provider ="Configuration.Implements.SqlConnectingProvider,Configuration,Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" ></ add >
       < add  name ="Xiaolin2Connecting"   ConnectionString ="Connecting....2"   Provider ="Configuration.Implements.SqlConnectingProvider,Configuration,Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" ></ add >
     
      <!--  <clear></clear> -->
       <!-- <remove name="Xiaolin2Connecting"/> -->
     </ ConnectionStrings >
    </ DataBaseConfig >   
</ configuration >

二： 步骤

处理节点的类

using System;
using System.Collections.Generic;
using System.Text;
using System.Configuration;
using System.ComponentModel;
using Configuration.Configuration.Common;

namespace Configuration.Configuration
{
    ///  < summary >
    /// DataBaseConfig节点
    ///  </ summary >
    public class DataBaseConfigure:ConfigurationSection
    {
        public DataBaseConfigure()
        { 
        }
        [ConfigurationProperty("DefaultConnectionString")]
        public string DefaultConnectionString
        {
            get { return (string)this["DefaultConnectionString"]; }
            set { this["DefaultConnectionString"] = value; }
        }
        ///  < summary >
        /// 子节点
        ///  </ summary >
        [ConfigurationProperty("ConnectionStrings", IsRequired = true)]
        public ConnectionStrings ConnectionStrings
        {
            get { return (ConnectionStrings)this["ConnectionStrings"]; }
            set { this["ConnectionStrings"] = value; }
        }
        public override string ToString()
        {
            return string.Format("DefaultConnectionString:{0}", this.DefaultConnectionString);
        }
    }
    ///  < summary >
    /// ConnectionString子节点(允许单个节点)
    ///  </ summary >
    public class ConnectionString : ConfigurationElement
    {
        public ConnectionString()
        { 
        }       
        public ConnectionString(string name)
        {
            Name =name;
        }
        [ConfigurationProperty("ConnectionString", IsRequired = true)]
        public string ConnectingString
        {
            get { return (string)this["ConnectionString"]; }
            set { this["ConnectionString"] = value; }
        }

        [ConfigurationProperty("name",IsRequired=true,IsKey=true)]
        public string Name
        {
            get { return (string)this["name"]; }
            set { this["name"] = value; }
        }
        [ConfigurationProperty("Provider", IsRequired = true)]
        [TypeConverter(typeof(AssemblyQualifiedTypeNameConverter))]
        public Type ConnectingProvider
        {
            get { return (Type)this["Provider"]; }
            set { this["Provider"] = value; }
        }

    }

    ///  < summary >
    /// ConnectionString子节点(允许多个节点)
    ///  </ summary >
    public class ConnectionStrings : ConfigurationElementCollection
    {
        public ConnectionStrings()
        {
        }
        protected override ConfigurationElement CreateNewElement()
        {
            return new ConnectionString();
        }
        protected override ConfigurationElement CreateNewElement(string elementName)
        {
            return new ConnectionString(elementName);
        }

        protected override object GetElementKey(ConfigurationElement element)
        {
            return ((ConnectionString)element).Name;
        }
        public ConnectionString this[int index]
        {
            get
            { return (ConnectionString)BaseGet(index); }
            set
            {
                if (BaseGet(index) != null)
                {
                    BaseRemoveAt(index);
                }
                BaseAdd(index, value);
            }
        }
        public int IndexOf(ConnectionString con)
        {
            return BaseIndexOf(con);
        }
        new public ConnectionString this[string name]
        {
            get
            {
                return (ConnectionString)BaseGet(name);
            }
        }
        public override ConfigurationElementCollectionType CollectionType
        {
            get
            {
                return ConfigurationElementCollectionType.AddRemoveClearMap;
            }
        }

        #region 添加/移除/清除节点
        public new string AddElementName
        {
            get
            {
                return base.AddElementName;
            }

            set
            {
                base.AddElementName = value;
            }
        }

        public void Add(ConnectionString con)
        {
            BaseAdd(con);
        }
        protected override void
            BaseAdd(ConfigurationElement element)
        {
            BaseAdd(element, false);
        }


        public void Remove(ConnectionString con)
        {
            if (BaseIndexOf(con) >= 0)
                BaseRemove(con.Name);
        }
        public void Remove(string name)
        {
            BaseRemove(name);
        }
        public void RemoveAt(int index)
        {
            BaseRemoveAt(index);
        }
        public new string RemoveElementName
        {
            get
            {
                return base.RemoveElementName;
            }
        }

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

            set
            {
                base.AddElementName = value;
            }

        }
        public void Clear()
        {
            BaseClear();
        }

        #endregion
        #region 集合数量
        public new int Count
        {
            get { return base.Count; }
        }
        #endregion     
    }

}

处理Type转换的类

using  System;
using  System.Collections.Generic;
using  System.Text;
using  System.Configuration;
using  System.ComponentModel;
using  Configuration.Properties;

namespace  Configuration.Configuration.Common
... {
   public  class AssemblyQualifiedTypeNameConverter : ConfigurationConverterBase
    ...{
         /**//// <summary>
        /// Returns the assembly qualified name for the passed in Type.
        /// </summary>
        /// <param name="context">The container representing this System.ComponentModel.TypeDescriptor.</param>
        /// <param name="culture">Culture info for assembly</param>
        /// <param name="value">Value to convert.</param>
        /// <param name="destinationType">Type to convert to.</param>
        /// <returns>Assembly Qualified Name as a string</returns>
        public override object ConvertTo(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value, Type destinationType)
        ...{
            Type typeValue = value as Type;
            if (typeValue == null)
            ...{
                throw new Exception("参数错误");
            }

            if (typeValue != null) return (typeValue).AssemblyQualifiedName;
            return null;
        }

        /**//// <summary>
        /// Returns a type based on the assembly qualified name passed in as data.
        /// </summary>
        /// <param name="context">The container representing this System.ComponentModel.TypeDescriptor.</param>
        /// <param name="culture">Culture info for assembly.</param>
        /// <param name="value">Data to convert.</param>
        /// <returns>Type of the data</returns>
        public override object ConvertFrom(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value)
        ...{
            string stringValue = (string)value;
            Type result = Type.GetType(stringValue, false);
            if (result == null)
            ...{
                throw new Exception("参数错误");
            }

            return result;
        }
    }
}

 配置中用到的两个类和代码中用到的一个接口

     interface  ConnectingProvider
     ... {
        string GetDB();
    }
     class  OleDBConnectingProvider:ConnectingProvider
     ... {
        ConnectingProvider Members#region ConnectingProvider Members
        public string GetDB()
        ...{
            return "this is OleDBConnecting";
        }
        #endregion
    }
     class  SqlConnectingProvider : ConnectingProvider
     ... {
        ConnectingProvider Members#region ConnectingProvider Members
        public string GetDB()
        ...{
            return "this is SqlConnecting";
        }
        #endregion
    }