c# 操作配置文件app.config
在c#出现以前，应用程序通常都是采用ini或xml作为配置文件，但c#出现后，大部分程序员还是选择用可操作性强的.config应用程序配置文件的。所以，为了操作方便，通常需要写一个通用类。网上有很多这样的通用类，但我觉得我写的这个通用辅助类对于我来说很方便，看各人喜好喽。

using system;
using system.collections.generic;
using system.text;
using system.configuration;

namespace schwann.commlibrary
{
    public class confighelper
    {
        /// <summary>
        /// 根据键值获取配置文件
        /// </summary>
        /// <param name="key">键值</param>
        /// <returns></returns>
        public static string getconfig(string key)
        {
            string val = string.empty;
            if (configurationmanager.apps教程ettings.allkeys.contains(key))
                val = configurationmanager.appsettings[key];
            return val;
        }

        /// <summary>
        /// 获取所有配置文件
        /// </summary>
        /// <returns></returns>
        public static dictionary<string, string> getconfig()
        {
            dictionary<string, string> dict = new dictionary<string, string>();
            foreach (string key in configurationmanager.appsettings.allkeys)
                dict.add(key, configurationmanager.appsettings[key]);
            return dict;
        }

        /// <summary>
        /// 根据键值获取配置文件
        /// </summary>
        /// <param name="key">键值</param>
        /// <param name="defaultvalue">默认值</param>
        /// <returns></returns>
        public static string getconfig(string key, string defaultvalue)
        {
            string val = defaultvalue;
            if (configurationmanager.appsettings.allkeys.contains(key))
                val = configurationmanager.appsettings[key];
            if (val == null)
                val = defaultvalue;
            return val;
        }

        /// <summary>
        /// 写配置文件,如果节点不存在则自动创建
        /// </summary>
        /// <param name="key">键值</param>
        /// <param name="value">值</param>
        /// <returns></returns>
        public static bool setconfig(string key, string value)
        {
            try
            {
                configuration conf = configurationmanager.openexeconfiguration(configurationuserlevel.none);
                if (!conf.appsettings.settings.allkeys.contains(key))
                    conf.appsettings.settings.add(key, value);
                else
                    conf.appsettings.settings[key].value = value;
                conf.save();
                return true;
            }
            catch { return false; }
        }

        /// <summary>
        /// 写配置文件(用键值创建),如果节点不存在则自动创建
        /// </summary>
        /// <param name="dict">键值集合</param>
        /// <returns></returns>
        public static bool setconfig(dictionary<string, string> dict)
        {
            try
            {
                if (dict == null || dict.count == 0)
                    return false;
                configuration conf = configurationmanager.openexeconfiguration(configurationuserlevel.none);
                foreach (string key in dict.keys)
                {
                    if (!conf.appsettings.settings.allkeys.contains(key))
                        conf.appsettings.settings.add(key, dict[key]);
                    else
                        conf.appsettings.settings[key].value = dict[key];
                }
                conf.save();
                return true;
            }
            catch { return false; }
        }
    }
}