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ConfigurationManager Class

Provides access to configuration files for client applications. This class cannot be inherited.

Namespace:  System.Configuration
Assembly:  System.Configuration (in System.Configuration.dll)

public ref class ConfigurationManager abstract sealed

The ConfigurationManager class enables you to access machine, application, and user configuration information. This class replaces the ConfigurationSettings class, which is deprecated.


The name and location of the application configuration file depend on the application's host. For more information, see Application Configuration Files.

You can use the built-in System.Configuration types or derive from them to handle configuration information. By using these types, you can work directly with configuration information and you can extend configuration files to include custom information.

The ConfigurationManager class includes members that enable you to perform the following tasks:

Notes to Implementers:

The Configuration class enables programmatic access for editing configuration files. You use one of the Open methods provided by ConfigurationManager. These methods return a Configuration object, which in turn provides the required methods and properties to handle the underlying configuration files. You can access these files for reading or writing.

To read the configuration files, use GetSection or GetSectionGroup to read configuration information. The user or process that reads must have the following permissions:

  • Read permission on the configuration file at the current configuration hierarchy level.

  • Read permissions on all the parent configuration files.

If your application needs read-only access to its own configuration, we recommend that you use the GetSection method. This method provides access to the cached configuration values for the current application, which has better performance than the Configuration class.

To write to the configuration files, use one of the Save methods. The user or process that writes must have the following permissions:

  • Write permission on the configuration file and directory at the current configuration hierarchy level.

  • Read permissions on all the configuration files.

The following example shows how to use the ConfigurationManager class in a console application. The code shows the following:

  • How to access the appSettings configuration section. If the section does not exist, it is created and added to the configuration file. The example creates the application configuration file if one does not exist.

  • How to access the Machine.config file to obtain information such as the default connection string, if it is defined, and the sections that are currently configured.


    When you create a project, make sure to add a reference to the System.Configuration assembly. This assembly contains the ConfigurationManager class.

A Visual Studio project with source code is available to accompany this topic: Download.

No code example is currently available or this language may not be supported.

The example works with elements that are similar to the ones illustrated in the following configuration file. These elements are generated the first time that you run the example.

<?xml version="1.0" encoding="utf-8"?>
        <section name="consoleSection" type="Samples.Aspnet.ConsoleSection, 
             ConfigurationManager_CS, Version=, Culture=neutral, PublicKeyToken=null" />
        <add key="NewKey0" value="Monday, March 30, 
             2009 1:36:33 PM" />
        <add key="NewKey1" value="Monday, March 30, 
             2009 1:36:40 PM" />
        <consoleElement background="Black" foreground="White" />


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0