VS2003中对于应用程序配置文件（app.config或者web.config)只提供了读取的功能。而在VS2005中，对于配置文件的功能有了很大的加强。
在VS2005中，对于应用程序配置文件的读写一般使用Configuration,ConfigurationManager两个类。
ConfigurationManager类为客户应用程序提供了一个访问的功能。
使用ConfigurationManager对象执行打开配置文件的操作后，将会返回一个Configuration的对象。
通过程序实现读写配置文件的代码如下所示：
1  创建配置文件中的配置节所对应的类。该类必须继承自ConfigurationSection
  public sealed class ConfigurationSections : ConfigurationSection
    {
        [ConfigurationProperty("filename", DefaultValue = "default.txt")]
        public string FileName
        {
            get
            {
                return (string)this["filename"];
            }
            set
            {
                this["filename"] = value;
            }
        }
    }
    public sealed class BusinessSpaceConfiguration : ConfigurationSection
    {
        [ConfigurationProperty("filename")]
        public string FileName
        {
            get
            {
                return (string)this["filename"];
            }
            set
            {
                this["filename"] = value;
            }
        }
    }

2  创建配置文件代码
   private static void WriteAppConfiguration()
        {
            try
            {
                ConfigurationSections configData = new ConfigurationSections();
                configData.FileName = "abc.txt";
                System.Configuration.Configuration  config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
                config.Sections.Remove("ConfigurationSections");
                config.Sections.Add("ConfigurationSections", configData);
                config.Save();

                BusinessSpaceConfiguration bsconfigData = new BusinessSpaceConfiguration();
                bsconfigData.FileName = "def.txt";
                System.Configuration.Configuration config1 = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
                config1.Sections.Remove("BusinessSpaceConfiguration");
                config1.Sections.Add("BusinessSpaceConfiguration", bsconfigData);
                config1.Save();                      
            }
            catch (Exception err)
            {
                Console.Write(err.Message);
            }
        }

3  生成的配置文件格式如下所示：
<?xml version="1.0" encoding="utf-8"?>
<configuration>
    <configSections>
        <section name="BusinessSpaceConfiguration" type="ConsoleApplication1.BusinessSpaceConfiguration, ConsoleApplication1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />
        <section name="ConfigurationSections" type="ConsoleApplication1.ConfigurationSections, ConsoleApplication1, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />
    </configSections>
    <BusinessSpaceConfiguration filename="def.txt" />
    <ConfigurationSections filename="abc.txt" />
</configuration>

3  读取应用程序配置文件
   private static void ReadAppConfiguration()
        {
            ConfigurationSections obj1 = ConfigurationManager.GetSection("ConfigurationSections") as ConfigurationSections;
            BusinessSpaceConfiguration obj2 = ConfigurationManager.GetSection("BusinessSpaceConfiguration") as BusinessSpaceConfiguration;
            Console.WriteLine(obj1.FileName);
            Console.WriteLine(obj2.FileName);