使用ExeConfigurationFileMap讀寫配置文件

http://www.cnblogs.com/anjou/archive/2011/06/02/2068504.html

using System;using System.IO;using System.Configuration;public class AppConfig{                    public string LastLoginId    {        get { return this.GetItem("LastLoginId"); }        set { this.SetItem("LastLoginId", value); }    }    private Configuration config;    public AppConfig()    {        ExeConfigurationFileMap configMap = new ExeConfigurationFileMap();        configMap.ExeConfigFilename = this.CreateConfig();        this.config = ConfigurationManager.OpenMappedExeConfiguration(configMap, ConfigurationUserLevel.None);    }    private string CreateConfig()    {        try        {            string configFile = AppDomain.CurrentDomain.BaseDirectory + @"app.config";            if (!File.Exists(configFile))            {                string xml = "<?xml version=\"1.0\" encoding=\"utf-8\" ?>\r\n<configuration>\r\n</configuration>";                using (StreamWriter sw = new StreamWriter(configFile))                {                    sw.Write(xml);                }            }            return configFile;        }        catch (Exception ex)        {            string msg = ex.Message;            throw;        }    }    private string GetItem(string item)    {        if (this.config.AppSettings.Settings[item] == null)        {            return string.Empty;        }        else        {            return this.config.AppSettings.Settings[item].Value;        }    }    private void SetItem(string item, string value)    {        if (this.config.AppSettings.Settings[item] == null)        {            this.config.AppSettings.Settings.Add(item, value);        }        else        {            this.config.AppSettings.Settings[item].Value = value;        }        this.Save();    }    private void Save()    {        try        {            this.config.Save(ConfigurationSaveMode.Modified);        }        catch (Exception ex)        {            string msg = ex.Message;            throw;        }    }}