使用ExeConfigurationFileMap读写配置文件

使用ExeConfigurationFileMap读写配置文件

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;
        }
    }
}