<?xml version="1.0" encoding="utf-8" ?>
<configuration><!--自定义配置节点--><configSections><sectionGroup name="OwnSectionA"><section name="AAA" type="AppLibrary.Configuration.MySelfInfoHandle,AppLibrary,Version=1.0.0.0"/><section name="BBB" type="System.Configuration.SingleTagSectionHandler"/></sectionGroup><sectionGroup name="OwnSectionB"><section name="aaa" type="System.Configuration.SingleTagSectionHandler"/><section name="bbb" type="System.Configuration.SingleTagSectionHandler"/></sectionGroup></configSections><!--自定义节点内容区域--><OwnSectionA><AAA><add key="name" value="huchen's homepage"/><add key="version" value="1.0"/></AAA></OwnSectionA><!--读取修改配置节点--><appSettings><clear/><add key ="Access" value="/Date/mvp.accdb"/><add key="Sql" value="null"/></appSettings></configuration>

 <connectionStrings><add name="SQLConn" connectionString="data Source=.\SQLEXPRESS;Integrated Security=SSPI;Initial Catalog=nORTHWIND"providerName="System.Data.SqlClient" /><add name="SQLConnB" connectionString="server=.\SQLEXPRESS;database=Northwind;uid=sa;pwd=de"providerName="System.Data.SqlClient"/></connectionStrings>

           System.Configuration.Configuration configuration = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration("~");
           System.Configuration.AppSettingsSection app = configuration.AppSettings;

app.Settings.Add(key, value); //增加

app.Settings[key].Value=value; //修改

app.Settings.Remove(key);  //删除

configuration.Save(System.Configuration.ConfigurationSaveMode.Modified);

           Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);

AppSettingsSection app = config.AppSettings;

app.Settings.Add(key, value); //增加
           app.Settings[key].Value=value; //修改

app.Settings.Remove(key);  //删除

config.Save(ConfigurationSaveMode.Modified);

            Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
            List<string> dir = new System.Collections.Generic.List<string>();
            AppSettingsSection app = config.AppSettings;
           
            string[] str = app.Settings.AllKeys;

for (int i = 0; i < str.Length; i++)
            {
                dir.Add(str[i] + "||" + app.Settings[str[i]].Value);
            }

this.listBox1.DataSource =dir;