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    说了对配置文件的修改，基本上都已经是全部了，后来也补充了SingleTagSectionHandler的访问，现在把对SingleTagSectionHandler的写以及一些能偷懒的方法一起说下，希望大家有好东西都能够分享下，有时用到了，就是好东西，不用到就当作是学习吧

提供二个访问配置文件的静态方法

        /// <summary>
        /// 打开默认的配置文件.exe.config
        /// </summary>
        /// <returns></returns>
        public static Configuration GetConfiguration()
        {
            return ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
        }

        /// <summary>
        /// 获取指定的配置文件。
        /// </summary>
        /// <param name="configFullPath">配置文件的全名称</param>
        /// <returns></returns>
        public static Configuration GetConfiguration(string configFullPath)
        {
            ExeConfigurationFileMap configFile = new ExeConfigurationFileMap();
            configFile.ExeConfigFilename = configFullPath;
            Configuration config = ConfigurationManager.OpenMappedExeConfiguration(configFile, ConfigurationUserLevel.None);
            return config;
        }

通过上两个静态方法可以获取到Configuration实例

获取SingleTagSectionHandler节点的值的多个方法

        /// <summary>
        /// 获取SingleTagSectionHandler某节点的值。
        /// </summary>
        /// <param name="config"></param>
        /// <param name="sectionName"></param>
        /// <param name="property"></param>
        /// <returns></returns>
        public static string GetSingleTagSectionItemValue(this Configuration config, string sectionName, string property)
        {
            Dictionary<string, string> dict = GetSingleTagSectionValues(config, sectionName);
            if (dict != null && dict.Count > 0)
            {
                if (dict.ContainsKey(property))
                    return (string)dict[property];
            }
            return null;
        }

        /// <summary>
        /// 获取SingleTagSectionHandler节点的值。
        /// </summary>
        /// <param name="config"></param>
        /// <param name="sectionName"></param>
        /// <returns></returns>
        public static Dictionary<string, string> GetSingleTagSectionValues(this Configuration config, string sectionName)
        {
            var section = config.GetSection(sectionName);
            if (section == null || section.SectionInformation == null)
                return null;
            ConfigXmlDocument xdoc = new ConfigXmlDocument();
            xdoc.LoadXml(section.SectionInformation.GetRawXml());
            System.Xml.XmlNode xnode = xdoc.ChildNodes[0];

            Dictionary<string, string> result = new Dictionary<string, string>();
            IDictionary dict = (IDictionary)(new SingleTagSectionHandler().Create(null, null, xnode));
            foreach (string str in dict.Keys)
            {
                result[str] = (string)dict[str];
            }

            return result;
        }

更新SingleTagSection只能通过Xml来实现，在些使用了ConfigXmlDocument类，通过更改DefaultSection的SectionInfomation的RawXml来完成，同时更改SectionInformation.Type为SingleTagSectionHandler的完全限定名。

更新和删除

        /// <summary>
        /// 更新配置节，相同的就修改，没有的就增加。
        /// </summary>
        /// <param name="config"></param>
        /// <param name="sectionName"></param>
        /// <param name="items"></param>
        public static void UpdateSingleTagSectionValues(this Configuration config, string sectionName, Dictionary<string, string> items)
        {
            Dictionary<string, string> orgItem = GetSingleTagSectionValues(config, sectionName);
            if (orgItem == null)
                orgItem = new Dictionary<string, string>();
            foreach (string key in items.Keys)
            {
                orgItem[key] = items[key];
            }
            UpdateSingleTagSection(config, sectionName, orgItem);
        }

        /// <summary>
        /// 删除配置点的一些配置。
        /// </summary>
        /// <param name="config"></param>
        /// <param name="sectionName"></param>
        /// <param name="items"></param>
        public static void RemoveSingleTagSectionValues(this Configuration config, string sectionName, Dictionary<string, string> items)
        {
            Dictionary<string, string> orgItem = GetSingleTagSectionValues(config, sectionName);
            if (orgItem != null)
            {
                foreach (string key in items.Keys)
                {
                    orgItem.Remove(key);
                }
                UpdateSingleTagSection(config, sectionName, orgItem);
            }
        }

        private static void UpdateSingleTagSection(Configuration config, string sectionName, Dictionary<string, string> items)
        {
            config.Sections.Remove(sectionName);

            DefaultSection section = new DefaultSection();
            config.Sections.Add(sectionName, section);
            ConfigXmlDocument xdoc = new ConfigXmlDocument();
            XmlNode secNode = xdoc.CreateNode(XmlNodeType.Element, sectionName, xdoc.NamespaceURI);
            xdoc.AppendChild(secNode);
            foreach (string key in items.Keys)
            {
                XmlAttribute attr = xdoc.CreateAttribute(key);
                attr.Value = items[key];
                secNode.Attributes.Append(attr);
            }
            section.SectionInformation.SetRawXml(xdoc.OuterXml);
            section.SectionInformation.Type = typeof(SingleTagSectionHandler).AssemblyQualifiedName;
            config.Save(ConfigurationSaveMode.Modified);
        }

应该还得提供一个对自定义的配置节访问和读写的方法，以更好的扩充

自定义配置节

        /// <summary>
        /// 获取自定义的配置节。
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="config"></param>
        /// <param name="sectionName"></param>
        /// <returns></returns>
        public static T GetCustomSection<T>(this Configuration config, string sectionName) where T : ConfigurationSection
        {
            return (T)config.GetSection(sectionName);
        }

        /// <summary>
        /// 保存自定义配置节。
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="config"></param>
        /// <param name="section"></param>
        /// <param name="sectionName"></param>
        public static void SaveCustomSection<T>(this Configuration config, T section, string sectionName) where T : ConfigurationSection
        {
            config.RemoveSection(sectionName);
            config.Sections.Add(sectionName, section);
            config.Save(ConfigurationSaveMode.Modified);
        }

    至于配置组，本人觉得用处不大，实现起来也很别扭，所在就不实现了，如果真的是很复杂的配置，建议自己定义一个配置节吧。

    下面一些懒人的方法，本人觉得还是很不错的，至少会省掉不少的开发时间。

通过反射对实体或静态属性进行赋值，在此假设obj如果为null就使用静态属性。

反射获取属性值

        private static void SetPropertiesValue(object obj, Dictionary<string, string> items, Type cfgEtyType)
        {
            BindingFlags bf = BindingFlags.Public;
            if (obj == null)
                bf |= BindingFlags.Static;
            else
                bf |= BindingFlags.Instance;

            PropertyInfo[] pinfos = cfgEtyType.GetProperties(bf);

            foreach (PropertyInfo p in pinfos)
            {
                try
                {
                    if (items.ContainsKey(p.Name))
                    {
                        string val = items[p.Name];
                        if (!string.IsNullOrEmpty(val))
                        {
                            if (p.PropertyType.IsEnum)
                            {
                                //判断是否为数字
                                if (isDigital(val))
                                {
                                    p.SetValue(obj, Enum.Parse(p.PropertyType, val, true), null);
                                }
                                else
                                {
                                    //判断是否存在该名称
                                    if (isExistEnumKey(p.PropertyType, val))
                                        p.SetValue(obj, Enum.Parse(p.PropertyType, val, true), null);
                                }
                            }
                            else if (p.PropertyType.IsValueType)   //值类型
                            {
                                MethodInfo minfo = p.PropertyType.GetMethod("Parse", new Type[] { typeof(string) });
                                if (minfo != null)
                                {
                                    p.SetValue(obj, minfo.Invoke(null, new object[] { val }), null);
                                }
                            }
                            else
                                p.SetValue(obj, val, null);
                        }
                        else if (!p.PropertyType.IsEnum && !p.PropertyType.IsValueType)
                            p.SetValue(obj, val, null);
                    }
                }
                catch (System.Exception ex)
                {
                    Console.WriteLine(ex.Message + "\n" + ex.StackTrace);
                }
            }
        }

        /// <summary>
        /// 判断枚举值是否为数字
        /// </summary>
        /// <param name="strValue"></param>
        /// <returns></returns>
        private static bool isDigital(string strValue)
        {
            return Regex.IsMatch(strValue, @"^(\d+)$");
        }

        /// <summary>
        /// 判断是否存在枚举的名称
        /// </summary>
        /// <param name="type"></param>
        /// <param name="keyName"></param>
        /// <returns></returns>
        private static bool isExistEnumKey(Type type, string keyName)
        {
            bool isExist = false;
            foreach (string key in Enum.GetNames(type))
            {
                if (key.Equals(keyName, StringComparison.OrdinalIgnoreCase))
                {
                    isExist = true;
                    break;
                }
            }
            return isExist;
        }

动态获取值，在此再次强调，属性值必需和配置节的Key等相同，包括大小写。

使用抽象类的静态属性来取出配置节的值

        /// <summary>
        /// 使用反射获取实体配置节的值，实体的静态属性必需和配置的Key相同。
        /// </summary>
        /// <param name="config">打开的配置实例</param>
        /// <typeparam name="T">要取值的类，类的静态属性要和Key值对应</typeparam>
        /// <param name="sectionName">T 对就的配置节的名称</param>
        public static void GetKeyValueSectionConfigValue<T>(this Configuration config, string sectionName) where T : class
        {
            try
            {
                Dictionary<string, string> dict = GetKeyValueSectionValues(config, sectionName);
                Type cfgEtyType = typeof(T);
                SetPropertiesValue(null, dict, cfgEtyType);
            }
            catch (System.Exception ex)
            {
                Console.WriteLine(ex.Message + "\n" + ex.StackTrace);
            }
        }

提供几个和Configuration实例无关的辅助方法，但也作为扩展方法来实现，以方便操作，只要由实例和抽象类来获取到HashTable的值，和反过来取得实例的值

辅助方法

        /// <summary>
        /// 由集合根据字段的属性生成实体。属性名为key，属性值为value。
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="config"></param>
        /// <param name="items"></param>
        /// <returns></returns>
        public static T GetConfigEntityByItems<T>(this Configuration config, Dictionary<string, string> items) where T : class
        {
            Type etyType = typeof(T);
            Func<object> func = etyType.CreateInstanceDelegate();
            object ety = func.Invoke();

            SetPropertiesValue(ety, items, etyType);

            return (T)ety;
        }

        /// <summary>
        /// 由实例生成配置的项。
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="config">没有实际使用到</param>
        /// <param name="instance"></param>
        /// <returns></returns>
        public static Dictionary<string, string> GetItemsByConfigEntity<T>(this Configuration config, T instance) where T : class
        {
            Type cfgEtyType = typeof(T);
            BindingFlags bf = BindingFlags.Public;
            if (instance == null)
                bf |= BindingFlags.Static;
            else
                bf |= BindingFlags.Instance;
            PropertyInfo[] pinfos = cfgEtyType.GetProperties(bf);
            Dictionary<string, string> dict = new Dictionary<string, string>();

            foreach (PropertyInfo p in pinfos)
            {
                dict[p.Name] = "" + p.GetValue(instance, null);
            }
            return dict;
        }

        /// <summary>
        /// 由类的静态属性生成配置项。
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <returns></returns>
        public static Dictionary<string, string> GetItemsByClass<T>(this Configuration config) where T : class
        {
            return GetItemsByConfigEntity<T>(config, null);
        }

从appSettings获取值

        /// <summary>
        /// 获取appSettings的配置值。Key值 和 T 的静态属性相同才能取出来。
        /// </summary>
        /// <param name="config">打开的配置实例</param>
        /// <typeparam name="T">要取值的类，类的静态属性要和Key值对应</typeparam>
        public static void GetAppSettingsConfigValue<T>(this Configuration config) where T : class
        {
            //通过反射自动值，增加属性只需把配置的key值和属性的名称相同即可。
            ////Type cfgType = typeof(ConfigUtility);

            ////MethodInfo getAppConfigMethod = cfgType.GetMethod("GetAppConfig", BindingFlags.Static | BindingFlags.Public);
            Type etyType = typeof(T);

            Dictionary<string, string> items = GetAppSettings(config);

            SetPropertiesValue(null, items, etyType);
        }

配置节的保存

保存配置节

        /// <summary>
        /// 保存 Section 配置的值。保存为DictionarySectionHandler配置节。
        /// </summary>
        /// <param name="config"></param>
        /// <typeparam name="T"></typeparam>
        /// <param name="sectionName"></param>
        public static void SaveKeyValueSectionConfig<T>(this Configuration config, string sectionName) where T : class
        {
            var orgsection = config.GetSection(sectionName);
            if (orgsection != null)
                config.Sections.Remove(sectionName);

            AppSettingsSection section = new AppSettingsSection();
            config.Sections.Add(sectionName, section);

            Type etyType = typeof(T);
            foreach (PropertyInfo pinfo in etyType.GetProperties(BindingFlags.Static | BindingFlags.Public))
            {
                string keyName = pinfo.Name;
                object objValue = pinfo.GetValue(null, null);
                ////section.Settings.Remove(keyName);
                section.Settings.Add(new KeyValueConfigurationElement(keyName, "" + objValue));
            }
            section.SectionInformation.Type = typeof(DictionarySectionHandler).AssemblyQualifiedName;
            config.Save(ConfigurationSaveMode.Modified);
        }

        /// <summary>
        /// 保存为 AppSettings 配置的值。
        /// </summary>
        /// <typeparam name="T"></typeparam>
        public static void SaveAppSettingsConfig<T>(this Configuration config) where T : class
        {
            try
            {
                Type etyType = typeof(T);
                foreach (PropertyInfo pinfo in etyType.GetProperties(BindingFlags.Static | BindingFlags.Public))
                {
                    string keyName = pinfo.Name;

                    object objValue = pinfo.GetValue(null, null);

                    UpdateAppSettingsItemNoSave(config, keyName, "" + objValue);
                }

                config.Save(ConfigurationSaveMode.Modified);
            }
            catch (System.Exception ex)
            {
                Console.WriteLine(ex.Message + "\n" + ex.StackTrace);
            }
        }

配置文件修改系列在此告一段落了，再附加上创建实体用到的Type的扩展，是从网络抄摘下来的，在本息用了代替Activator来创建实例，效率会快点。

View Code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Linq.Expressions;

namespace System
{
    public static class TypeExtensions
    {
        public static Func<object> CreateInstanceDelegate(this Type type)
        {
            NewExpression newExp = Expression.New(type);
            Expression<Func<object>> lambdaExp =
                Expression.Lambda<Func<object>>(newExp, null);
            Func<object> func = lambdaExp.Compile();
            return func;
        }

        public static Func<T, object> CreateInstanceDelegate<T>(this Type type)
        {
            Type paramType = typeof(T);
            var construtor = type.GetConstructor(new Type[] { paramType });
            var param = new ParameterExpression[] { Expression.Parameter(paramType, "arg") };

            NewExpression newExp = Expression.New(construtor, param);
            Expression<Func<T, object>> lambdaExp =
                Expression.Lambda<Func<T, object>>(newExp, param);
            Func<T, object> func = lambdaExp.Compile();
            return func;
        }

        public static Func<T1, T2, object> CreateInstanceDelegate<T1, T2>(this　Type type)
        {
            var types = new Type[] { typeof(T1), typeof(T2) };
            var construtor = type.GetConstructor(types);
            int i = 0;
            var param = types.Select(t => Expression.Parameter(t, "arg" + (i++))).ToArray();
            NewExpression newExp = Expression.New(construtor, param);
            Expression<Func<T1, T2, object>> lambdaExp = Expression.Lambda<Func<T1, T2, object>>(newExp, param);
            Func<T1, T2, object> func = lambdaExp.Compile();
            return func;
        }

        //以下方法中的Lambda表达式“Expression<Func<object[], object>> ”已经定义参数是object[], 而构造函数的参数却不能自动转化。当使用以下代码作测试，

        //////以下代码有bug!
        ////public static Func<object[], object> CreateInstanceDelegate(this Type type, params  object[] args)
        ////{
        ////    var construtor = type.GetConstructor(args.Select(c => c.GetType()).ToArray());
        ////    var param = buildParameters(args);

        ////    NewExpression newExp = Expression.New(construtor, param);
        ////    Expression<Func<object[], object>> lambdaExp =
        ////        Expression.Lambda<Func<object[], object>>(newExp, param);
        ////    Func<object[], object> func = lambdaExp.Compile();
        ////    return func;
        ////}

        ////static ParameterExpression[] buildParameters(object[] args)
        ////{
        ////    int i = 0;
        ////    List<ParameterExpression> list = new List<ParameterExpression>();
        ////    foreach (object arg in args)
        ////    {
        ////        list.Add(Expression.Parameter(arg.GetType(), "arg" + (i++)));
        ////    }
        ////    return list.ToArray();
        ////}

    }
} 

-----------------The End----------------

谢谢大家！

本文出自：http://www.cnblogs.com/Yjianyong/archive/2011/10/28/2227924.html