In Beta 2 there are now two classes, ConfigurationManager and the WebConfigurationManager.The ConfigurationManager will not longer have methods for getting the web applications configuration file. Instead you shoud use the WebConfigurationFile.If you want to update or add sections to the app.config,you should use the ConfigurationManager class.
在测试版2.0中有两个类：ConfigurationManager和WebConfigurationManager.ConfigurationManager不再是从网页配置文件获取设置的方法，替代它的是使用WebConfigurationManager.如果你想更新或者是添加节到文件app.config，你须使用ConfigurationManager类。
The following is an example of how you can add an appSettings key to the web.config and also how to update an existing key:
接下来的一个例子是如何添加程序设置键值到web.config与如何更新存在的键值：
Configuration config=WebConfigurationManager.OpenWebConfiguration("~");
if(config.AppSettings.Settings["MyAppKey"]==null)
config.AppSettings.Settings.Add("MyAppKey","Hello!");
else
config.AppSettings.Settings["MyAppKey"].Value="Hello2!";
config.Save();
The WebConfigurationManager class has the following properties and methods:
WebConfigurationManager 类有以下属性和方法：
AppSettings
Gets a NameValueCollection class that has the values added to the <appSettings> section.
得到NameValueCollection 类以便有个值添加到<appSettings>节中。
ConnectionStrings
Gets a ConnectionStringSettingsCollection class that will have the connections strings added to the <connectionString> section.
得到个ConnectionStringSettingsCollection类，类中将有个连接字符串属性，以便添加到<connectionString>节中。
GetSection
With the GetSection you can get a specific section from the configuration file.
在GetSection下你能从设置文件中得到个指定的节。
GetWebApplicationSection
With the GetWebApplicationSection you can get the specified section from the web applications configuration file.
在GetWebApplicationSection下你能从网页设置文件中得到个指定的节。
Note:This method retrieves the specified configuration section from the configuration file located at the root folder of your Web application.If you want to retrieve the configuration section from the current Web application directory use the GetSection method.
注：这个方法返回定位在你网页程序root 文件中配置文件的配置节。如果你想返回当前网页程序目录下的配置节，可以使用GetSection方法。
OpenMachineConfiguration
With the OpenMachineConfiguration,you configure the machine.config file.
使用OpenMachineConfiguration,你可以配置machine.config文件。
OpenMappedMachineConfiguration
With the OpenMappedMachineConfiguration,you can open a specifed configuration file.
使用OpenMappedMachineConfiguration,你能打开个指定的配置文件。
OpenWebConfiguration
With the OpenWebConfiguration,you can open the web applications configuration file.
使用OpenWebConfiguration，你可以打开网页程序配置文件。
OpenMappedWebConfiguration
With the OpenMappedWebConfiguration,you can open a specifed web configuration file.
使用OpenmappedWebConfiguration,你可以打开指定的网页配置文件。