共用方式為


clear Element for appSettings (General Settings Schema) 

Removes all references to inherited custom application settings, allowing only the settings that are added by the current add element.

<clear />

Attributes and Elements

The following sections describe attributes, child elements, and parent elements.

Attributes

None.

Child Elements

None.

Parent Elements

Element Description

configuration

Specifies the required root element in every configuration file that is used by the common language runtime and the .NET Framework applications.

system.web

Specifies the root element for the ASP.NET configuration settings in a configuration file and contains configuration elements that configure ASP.NET Web applications and control how the applications behave.

appSettings

Contains custom application settings, such as file paths, XML Web service URLs, or any information that is stored in the .ini file for an application.

Remarks

The clear element removes all references to inherited custom application settings that are stored in the appSettings element, allowing only the settings that are added by the current add element.

The appSettings element stores custom application configuration information, such as file paths, XML Web service URLs, or any information that is stored in the .ini file for an application. The key/value pairs that are specified in the appSettings element can be accessed in code by using the ConfigurationSettings class.

Default Configuration

The following default appSettings element is not explicitly configured in the Machine.config file or in the root Web.config file. However, it is the default configuration that is returned by application.

   <appSettings file="">
      <settings>
         <clear />
      </settings>
   </appSettings>

Element Information

Configuration section handler

AppSettingsSection

Configuration member

Clear

Configurable locations

Machine.config

Root-level Web.config

Application-level Web.config

Virtual or physical directory–level Web.config

Requirements

Microsoft Internet Information Services (IIS) version 5.0, 5.1, or 6.0

The .NET Framework version 1.0, 1.1, or 2.0

Microsoft Visual Studio 2003 or Visual Studio 2005

See Also

Reference

appSettings Element (General Settings Schema)
configuration Element (General Settings Schema)
add Element for appSettings (General Settings Schema)
remove Element for appSettings (General Settings Schema)

Concepts

Securing ASP.NET Configuration
ASP.NET Configuration Scenarios

Other Resources

General Configuration Settings (ASP.NET)
ASP.NET Configuration Settings
ASP.NET Configuration Files