兩種讀寫配置文件的方案(app.config與web.config通用)

第一種方法：采用MS現(xiàn)有的ConfigurationManager來進(jìn)行讀寫

using System.Configuration;namespace Zwj.TEMS.Common{    public abstract class ConfigHelper    {        PRivate ConfigHelper()        { }        /// <summary>        /// 獲取配置值        /// </summary>        /// <param name="key"></param>        /// <returns></returns>        public static string GetAppSettingValue(string key)        {            return ConfigurationManager.AppSettings[key];        }        /// <summary>        /// 設(shè)置配置值（存在則更新，不存在則新增）        /// </summary>        /// <param name="key"></param>        /// <param name="value"></param>        public static void SetAppSettingValue(string key, string value)        {            var config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);            var setting = config.AppSettings.Settings[key];            if (setting==null)            {                config.AppSettings.Settings.Add(key, value);            }            else            {                setting.Value = value;            }            config.Save(ConfigurationSaveMode.Modified);            ConfigurationManager.RefreshSection("appSettings");        }        /// <summary>        /// 刪除配置值        /// </summary>        /// <param name="key"></param>        public static void RemoveAppSetting(string key)        {            var config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);            config.AppSettings.Settings.Remove(key);            config.Save(ConfigurationSaveMode.Modified);            ConfigurationManager.RefreshSection("appSettings");        }        /// <summary>        /// 獲取連接字符串        /// </summary>        /// <param name="name"></param>        /// <returns></returns>        public static string GetConnectionString(string name)        {          return  ConfigurationManager.ConnectionStrings[name].ConnectionString;        }        /// <summary>        /// 設(shè)置連接字符串的值（存在則更新，不存在則新增）        /// </summary>        /// <param name="name"></param>        /// <param name="connstr"></param>        /// <param name="provider"></param>        public static void SetConnectionString(string name,string connstr, string provider)        {            var config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);            ConnectionStringSettings connStrSettings = config.ConnectionStrings.ConnectionStrings[name];            if (connStrSettings != null)            {                connStrSettings.ConnectionString = connstr;                connStrSettings.ProviderName = provider;            }            else            {                connStrSettings = new ConnectionStringSettings(name, connstr, provider);                config.ConnectionStrings.ConnectionStrings.Add(connStrSettings);            }            config.Save(ConfigurationSaveMode.Modified);            ConfigurationManager.RefreshSection("connectionStrings");        }        /// <summary>        /// 刪除連接字符串配置項        /// </summary>        /// <param name="name"></param>        public static void RemoveConnectionString(string name)        {            var config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);            config.ConnectionStrings.ConnectionStrings.Remove(name);            config.Save(ConfigurationSaveMode.Modified);            ConfigurationManager.RefreshSection("connectionStrings");        }    }}

　注意：不能直接使用ConfigurationManager.AppSettings及ConfigurationManager.ConnectionStrings進(jìn)行寫操作（即：Add,Remove）,因為這兩個屬性是只讀的，本人之前也疑惑，明明能夠調(diào)用Add,Remove方法，但使用時卻報錯。

第二種方法：采用原生的xml+XPATH來讀寫（來源于網(wǎng)絡(luò)）

//==============================================// FileName: ConfigManager// Description: 靜態(tài)方法業(yè)務(wù)類，用于對C#、asp.net中的WinForm & WebForm 項目程序配置文件// app.config和web.config的[appSettings]和[connectionStrings]節(jié)點(diǎn)進(jìn)行新增、修改、刪除和讀取相關(guān)的操作。//==============================================using System;using System.Data;using System.Configuration;using System.Web;using System.Collections.Generic;using System.Text;using System.Xml;public enum ConfigurationFile{    AppConfig = 1,    WebConfig = 2}/// <summary>/// ConfigManager 應(yīng)用程序配置文件管理器/// </summary>public class ConfigManager{    public ConfigManager()    {        //        // TODO: 在此處添加構(gòu)造函數(shù)邏輯        //    }    /// <summary>    /// 對[appSettings]節(jié)點(diǎn)依據(jù)Key值讀取到Value值，返回字符串    /// </summary>    /// <param name="configurationFile">要操作的配置文件名稱,枚舉常量</param>    /// <param name="key">要讀取的Key值</param>    /// <returns>返回Value值的字符串</returns>    public static string ReadValueByKey(ConfigurationFile configurationFile, string key)    {        string value = string.Empty;        string filename = string.Empty;        if (configurationFile.ToString() == ConfigurationFile.AppConfig.ToString())        {            filename = System.Windows.Forms.application.ExecutablePath + ".config";        }        else        {            filename = System.AppDomain.CurrentDomain.BaseDirectory + "web.config";        }        XmlDocument doc = new XmlDocument();        doc.Load(filename); //加載配置文件         XmlNode node = doc.SelectSingleNode("http://appSettings"); //得到[appSettings]節(jié)點(diǎn)         ////得到[appSettings]節(jié)點(diǎn)中關(guān)于Key的子節(jié)點(diǎn)        XmlElement element = (XmlElement)node.SelectSingleNode("http://add[@key='" + key + "']");        if (element != null)        {            value = element.GetAttribute("value");        }        return value;    }    /// <summary>    /// 對[connectionStrings]節(jié)點(diǎn)依據(jù)name值讀取到connectionString值，返回字符串    /// </summary>    /// <param name="configurationFile">要操作的配置文件名稱,枚舉常量</param>    /// <param name="name">要讀取的name值</param>    /// <returns>返回connectionString值的字符串</returns>    public static string ReadConnectionStringByName(ConfigurationFile configurationFile, string name)    {        string connectionString = string.Empty;        string filename = string.Empty;        if (configurationFile.ToString() == ConfigurationFile.AppConfig.ToString())        {            filename = System.Windows.Forms.Application.ExecutablePath + ".config";        }        else        {            filename = System.AppDomain.CurrentDomain.BaseDirectory + "web.config";        }        XmlDocument doc = new XmlDocument();        doc.Load(filename); //加載配置文件         XmlNode node = doc.SelectSingleNode("http://connectionStrings"); //得到[appSettings]節(jié)點(diǎn)         ////得到[connectionString]節(jié)點(diǎn)中關(guān)于name的子節(jié)點(diǎn)        XmlElement element = (XmlElement)node.SelectSingleNode("http://add[@name='" + name + "']");        if (element != null)        {            connectionString = element.GetAttribute("connectionString");        }        return connectionString;    }    /// <summary>    /// 更新或新增[appSettings]節(jié)點(diǎn)的子節(jié)點(diǎn)值，存在則更新子節(jié)點(diǎn)Value,不存在則新增子節(jié)點(diǎn)，返回成功與否布爾值    /// </summary>    /// <param name="configurationFile">要操作的配置文件名稱,枚舉常量</param>    /// <param name="key">子節(jié)點(diǎn)Key值</param>    /// <param name="value">子節(jié)點(diǎn)value值</param>    /// <returns>返回成功與否布爾值</returns>    public static bool UpdateOrCreateAppSetting(ConfigurationFile configurationFile, string key, string value)    {        bool isSuccess = false;        string filename = string.Empty;        if (configurationFile.ToString() == ConfigurationFile.AppConfig.ToString())        {            filename = System.Windows.Forms.Application.ExecutablePath + ".config";        }        else        {            filename = System.AppDomain.CurrentDomain.BaseDirectory + "web.config";        }        XmlDocument doc = new XmlDocument();        doc.Load(filename); //加載配置文件         XmlNode node = doc.SelectSingleNode("http://appSettings"); //得到[appSettings]節(jié)點(diǎn)         try        {            ////得到[appSettings]節(jié)點(diǎn)中關(guān)于Key的子節(jié)點(diǎn)            XmlElement element = (XmlEleme