【分享】操作配置文件帮助类

    配置文件时开发当中常用到，使用它不仅能增加程序的灵活性，而且易于维护。项目当中经常使用配置文件来配置Quartz.NET任务调度框架cron表达式，于是就封装了一个帮助类，现在分享出来希望对大家有帮助。

    首先场景还是用Quartz.NET执行定期任务，cron表达式放在配置文件中。配置文件内容如下：

<configuration>
  <configSections>
    <section name="JobInfo" type="System.Configuration.DictionarySectionHandler" />
  </configSections>  
  <JobInfo>
    <!--cron表达式-http://www.cronmaker.com/-->
    <add key="ChangeStatusJobInfo" value="0 0 0 1/1 * ? *" />
    </JobInfo>
</configuration>   

    上面先定义了一个name为JobInfo的Section。然后在JobInfo节点里存放”ChangStatusJobInfo”这个任务的执行时间，值用cron来表示。它会在每天的00:00:00执行。

    下面是Helper实现代码。采用单例模式创建Helper，使用强类型的形式进行配置内容的读写。

/******************************************************************* 
 * FileName: ConfigHelper.cs
 * Author   : Qiang Kong
 * Date : 2015-11-10 14:54:39
 * Desc : 
 * 
 * 强类型操作配置文件
 * *******************************************************************/

using System;
using System.Configuration;
using System.IO;
using System.Reflection;
using System.Xml;

namespace SendCloudSDK.Utis
{
    internal class ConfigHelper
    {
        private const string ValFlag = "value";
        private const string Epilogue = ">";

        private static ConfigHelper _instance;

        public static bool CreateImpl(string configPath = null)
        {
            var instance = GetInstance(configPath);
            return instance != null;
        }

        public static ConfigHelper GetInstance()
        {
            return GetInstance(null);
        }

        public static ConfigHelper GetInstance(string configPath)
        {
            return _instance ?? (_instance = new ConfigHelper(configPath));
        }

        private readonly ExeConfigurationFileMap _exeConfigMap;

        private ConfigHelper(string configPath)
        {
            if (string.IsNullOrWhiteSpace(configPath))
            {
                configPath = String.Format("{0}\{1}", AppDomain.CurrentDomain.BaseDirectory.TrimEnd('/', '\'), "SendCloud.config");

                if (!File.Exists(configPath))
                {
                    string[] filePaths = Directory.GetFiles(AppDomain.CurrentDomain.BaseDirectory, "配置文件名称.config", SearchOption.AllDirectories);
                    if (filePaths.Length == 0)
                    {
                        throw new Exception("未找到配置文件");
                    }

                    configPath = filePaths[0];
                }

            }

            _exeConfigMap = new ExeConfigurationFileMap { ExeConfigFilename = configPath };
        }

        public T GetSection<T>(string sectionName) where T : class,new()
        {
            return GetSection<T>(sectionName, null);
        }

        public T GetSection<T>(string sectionName, string sectionGroup) where T : class, new()
        {
            T result = new T();
            var section = GetSection(sectionName, sectionGroup);
            if (section != null)
            {
                Type t = typeof(T);
                foreach (KeyValueConfigurationElement kv in section)
                {
                    t.GetProperty(kv.Key).SetValue(result, kv.Value, null);
                }
            }
            return result;
        }

        public void ModifySection<T>(string sectionName, T entity) where T : class, new()
        {
            ModifySection<T>(sectionName, null, entity);
        }

        public void ModifySection<T>(string sectionName, string sectionGroupName, T entity) where T : class,new()
        {
            try
            {


                var configuration = ConfigurationManager.OpenMappedExeConfiguration(_exeConfigMap, ConfigurationUserLevel.None);

                ConfigurationSection section;
                if (string.IsNullOrWhiteSpace(sectionGroupName))
                {
                    section = configuration.GetSection(sectionName);
                }
                else
                {

                    var group = configuration.GetSectionGroup(sectionGroupName);
                    if (group == null)
                    {
                        throw new Exception("SectionGroup为空");
                    }
                    section = group.Sections[sectionName];
                }


                if (section != null)
                {

                    var info = section.SectionInformation;
                    var dicAssemblyName = typeof(DictionarySectionHandler).FullName;
                    if (!info.Type.Contains(dicAssemblyName))
                    {
                        throw new Exception("暂时支持DictionarySectionHandler的节点");
                    }

                    var xmlStr = info.GetRawXml();

                    Type st = entity.GetType();
                    PropertyInfo[] spis = st.GetProperties();

                    int curIndex = 0;
                    foreach (var item in spis)
                    {
                        var key = item.Name;

                        curIndex = xmlStr.IndexOf(string.Format("key="{0}"", key), curIndex, StringComparison.Ordinal);
                        if (curIndex != -1)
                        {
                            var normalStr = item.GetValue(entity, null)
                                .ToString()
                                .Replace("<", "&lt;")
                                .Replace("&", "&amp;")
                                .Replace(">", "&gt;").Replace("'", "&apos;").Replace(""", "&quot;");
                            var tagStr = string.Format("key="{0}" {3}="{1}" /{2}", key, normalStr, Epilogue, ValFlag);
                            int endIndex = xmlStr.IndexOf(Epilogue, curIndex, StringComparison.Ordinal);
                            var ss = xmlStr.Substring(curIndex, endIndex - curIndex + 1);
                            xmlStr = xmlStr.Replace(ss, tagStr);
                            curIndex = endIndex;
                        }
                        else
                        {
                            curIndex = 0;
                        }

                    }

                    info.SetRawXml(xmlStr);
                    info.Type = dicAssemblyName;

                    configuration.Save(ConfigurationSaveMode.Modified);
                }
            }
            catch (Exception ex)
            {

                throw new Exception(ex.Message);
            }
        }

        public string GetVal(string key, string sectionName)
        {
            string result = string.Empty;
            var kvc = GetSection(sectionName);

            foreach (KeyValueConfigurationElement kv in kvc)
            {
                if (key.Equals(kv.Key))
                {
                    result = kv.Value;
                    break;
                }
            }

            return result;
        }

        public string SetVal(string key, string val, string sectionName)
        {
            return "";
        }

        private KeyValueConfigurationCollection GetSection(string sectionName, string sectionGroupName = null)
        {
            var result = new KeyValueConfigurationCollection();

            if (string.IsNullOrEmpty(sectionName))
            {
                return result;
            }

            var configuration = ConfigurationManager.OpenMappedExeConfiguration(_exeConfigMap,
                ConfigurationUserLevel.None);

            ConfigurationSection section;
            if (string.IsNullOrWhiteSpace(sectionGroupName))
            {
                section = configuration.GetSection(sectionName);
            }
            else
            {

                var group = configuration.GetSectionGroup(sectionGroupName);
                if (group == null)
                {
                    throw new Exception("sectionGroup为空");
                }
                section = group.Sections[sectionName];
            }

            if (section != null)
            {

                ConfigXmlDocument vv = new ConfigXmlDocument();
                vv.LoadXml(section.SectionInformation.GetRawXml());

                var items = vv.GetElementsByTagName("add");
                XmlAttributeCollection attributes;
                foreach (XmlNode item in items)
                {
                    attributes = item.Attributes;
                    if (attributes != null && attributes.Count == 2)
                    {
                        result.Add(attributes["key"].Value, attributes["value"].Value);
                    }
                }
            }
            return result;
        }

        private string GetSectionXml(string sectionName)
        {
            string xmlStr = string.Empty;
            var configuration = ConfigurationManager.OpenMappedExeConfiguration(_exeConfigMap, ConfigurationUserLevel.None);
            var section = configuration.GetSection(sectionName);
            if (section != null)
            {
                xmlStr = section.SectionInformation.GetRawXml();
            }

            return xmlStr;
        }
    }
}

    使用方式：

//1、创建一个JobInfo类 
    class JobInfo
    {
        public string ChangeStatusJobInfo { get; set; }
    }


    class Program
    {
        static void Main(string[] args)
        {
            //2、预初始化ConfigHelper
            ConfigHelper.CreateImpl();
            //3、调用
            var jobInfo = ConfigHelper.GetInstance().GetSection<JobInfo>("JobInfo>");
            string cron = jobInfo.ChangeStatusJobInfo;
        }
    }