c# config类

[CommandMethod("ChangeXml")]
public static void ChangeXml()
{
   string filename = "../MineData.DLL";
   string newName = "preUrl";
   string newConString = "aaaa";
   string newProviderName = "bbbb";
   if (filename == null)
       filename = GLBL.GetExecutingDllFullFileName();
   System.Configuration.Configuration config = System.Configuration.ConfigurationManager.OpenExeConfiguration(filename);

   if (config == null)
       return;
   bool exist = false; //记录该连接串是否已经存在  
   //如果要更改的连接串已经存在  
   if (config.ConnectionStrings.ConnectionStrings[newName] != null)
   {
       exist = true;
   }
   // 如果连接串已存在，首先删除它  
   if (exist)
   {
       config.ConnectionStrings.ConnectionStrings.Remove(newName);
   }
   //新建一个连接字符串实例  
   //ConnectionStringSettings mySettings =
   //    new ConnectionStringSettings(newName, newConString, newProviderName);
   ConnectionStringSettings mySettings =
      new ConnectionStringSettings(newName, newConString, newProviderName);
   // 将新的连接串添加到配置文件中.  
   config.ConnectionStrings.ConnectionStrings.Add(mySettings);
   // 保存对配置文件所作的更改  
   config.Save(ConfigurationSaveMode.Modified);
   // 强制重新载入配置文件的ConnectionStrings配置节  
   ConfigurationManager.RefreshSection("connectionStrings");
}

[CommandMethod("ChangeXml")]
public static void ChangeXml()
{
   string filename = "../MineData.DLL";
   string newName = "preUrl";
   string newConString = "aaaa";
   string newProviderName = "bbbb";
   if (filename == null)
       filename = GLBL.GetExecutingDllFullFileName();
   System.Configuration.Configuration config = System.Configuration.ConfigurationManager.OpenExeConfiguration(filename);

   if (config == null)
       return;
   bool exist = false;
   if (config.ConnectionStrings.ConnectionStrings[newName] != null)
   {
       exist = true;
   }
   if (exist)
   {
       config.ConnectionStrings.ConnectionStrings.Remove(newName);
   }
   //ConnectionStringSettings mySettings =
   //    new ConnectionStringSettings(newName, newConString, newProviderName);
   ConnectionStringSettings mySettings =
      new ConnectionStringSettings(newName, newConString, newProviderName);
   config.ConnectionStrings.ConnectionStrings.Add(mySettings);
   config.Save(ConfigurationSaveMode.Modified);
   ConfigurationManager.RefreshSection("connectionStrings");
}

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

namespace MineData
{
    public class AppConfigFunction
    {
        /// <summary>
        /// 依据连接串名字connectionName返回数据连接字符串  
        /// </summary>
        ///<param name="config">Configuration对象</param> 
        /// <param name="connectionName"></param>
        /// <returns></returns>
        public static string GetConnectionStringsConfig(Configuration config, string connectionName)
        {
            if (config == null)
                return string.Empty;
            string connectionString =
                config.ConnectionStrings.ConnectionStrings[connectionName].ConnectionString.ToString();
            return connectionString;
        }
        ///<summary> 
        ///更新连接字符串  
        ///</summary> 
        ///<param name="config">Configuration对象</param> 
        ///<param name="newName">连接字符串名称</param> 
        ///<param name="newConString">连接字符串内容</param> 
        ///<param name="newProviderName">数据提供程序名称</param> 
        public static void UpdateConnectionStringsConfig(Configuration config, string newName, string newConString, string newProviderName)
        {
            if (config == null)
                return;
            bool exist = false; //记录该连接串是否已经存在  
            //如果要更改的连接串已经存在  
            if (config.ConnectionStrings.ConnectionStrings[newName] != null)
            {
                exist = true;
            }
            // 如果连接串已存在，首先删除它  
            if (exist)
            {
                config.ConnectionStrings.ConnectionStrings.Remove(newName);
            }
            //新建一个连接字符串实例  
            ConnectionStringSettings mySettings =
                new ConnectionStringSettings(newName, newConString, newProviderName);
            // 将新的连接串添加到配置文件中.  
            config.ConnectionStrings.ConnectionStrings.Add(mySettings);
            // 保存对配置文件所作的更改  
            config.Save(ConfigurationSaveMode.Modified);
            // 强制重新载入配置文件的ConnectionStrings配置节  
            ConfigurationManager.RefreshSection("connectionStrings");
        }
        ///<summary> 
        ///返回*.exe.config文件中appSettings配置节的value项  
        ///</summary> 
        ///<param name="config">Configuration对象</param> 
        ///<param name="strKey"></param> 
        ///<returns></returns> 
        public static string GetAppConfig(Configuration config, string strKey)
        {
            if (config == null)
                return string.Empty;
            foreach (string key in config.AppSettings.Settings.AllKeys)
            {
                if (key == strKey)
                {
                    return config.AppSettings.Settings[strKey].Value.ToString();
                }
            }
            return null;
        }
        ///<summary>  
        ///在*.exe.config文件中appSettings配置节增加一对键值对  
        ///</summary>  
        ///<param name="config">Configuration对象</param> 
        ///<param name="newKey"></param>  
        ///<param name="newValue"></param>  
        public static void UpdateAppConfig(Configuration config, string newKey, string newValue)
        {
            if (config == null)
                return;
            bool exist = false;
            foreach (string key in config.AppSettings.Settings.AllKeys)
            {
                if (key == newKey)
                {
                    exist = true;
                }
            }
            if (exist)
            {
                config.AppSettings.Settings.Remove(newKey);
            }
            config.AppSettings.Settings.Add(newKey, newValue);
            config.Save();
            ConfigurationManager.RefreshSection("appSettings");
        }
    }
}