Configuration Class

Definition

public ref class Configuration sealed

public sealed class Configuration

type Configuration = class

Public NotInheritable Class Configuration

Inheritance

Object

Configuration

Examples

The following code example demonstrates how to use the Configuration class to access configuration file elements.

using System;
using System.Collections.Generic;
using System.Text;
using System.Configuration;
using System.Globalization;
using System.ComponentModel;
using System.Collections.Specialized;

// Before compiling this application, 
// remember to reference the System.Configuration assembly in your project. 
#region CustomSection class

// Define a custom section. This class is used to
// populate the configuration file.
// It creates the following custom section:
// <CustomSection name="Contoso" url="http://www.contoso.com" port="8080" />.
public sealed class CustomSection : ConfigurationSection
{

 public CustomSection()
 {
 }

 [ConfigurationProperty("name",
 DefaultValue = "Contoso",
 IsRequired = true,
 IsKey = true)]
 public string Name
 {
 get
 {
 return (string)this["name"];
 }
 set
 {
 this["name"] = value;
 }
 }

 [ConfigurationProperty("url",
 DefaultValue = "http://www.contoso.com",
 IsRequired = true)]
 [RegexStringValidator(@"\w+:\/\/[\w.]+\S*")]
 public string Url
 {
 get
 {
 return (string)this["url"];
 }
 set
 {
 this["url"] = value;
 }
 }

 [ConfigurationProperty("port",
 DefaultValue = (int)8080,
 IsRequired = false)]
 [IntegerValidator(MinValue = 0,
 MaxValue = 8080, ExcludeRange = false)]
 public int Port
 {
 get
 {
 return (int)this["port"];
 }
 set
 {
 this["port"] = value;
 }
 }
}

#endregion

#region Using Configuration Class
class UsingConfigurationClass
{


 // Show how to create an instance of the Configuration class
 // that represents this application configuration file. 
 static void CreateConfigurationFile()
 {
 try
 {

 // Create a custom configuration section.
 CustomSection customSection = new CustomSection();

 // Get the current configuration file.
 System.Configuration.Configuration config =
 ConfigurationManager.OpenExeConfiguration(
 ConfigurationUserLevel.None);

 // Create the custom section entry 
 // in <configSections> group and the 
 // related target section in <configuration>.
 if (config.Sections["CustomSection"] == null)
 {
 config.Sections.Add("CustomSection", customSection);
 }

 // Create and add an entry to appSettings section.
 
 string conStringname="LocalSqlServer";
 string conString = @"data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|aspnetdb.mdf;User Instance=true";
 string providerName="System.Data.SqlClient";

 ConnectionStringSettings connStrSettings = new ConnectionStringSettings();
 connStrSettings.Name = conStringname;
 connStrSettings.ConnectionString= conString;
 connStrSettings.ProviderName = providerName;

 config.ConnectionStrings.ConnectionStrings.Add(connStrSettings);
 
 // Add an entry to appSettings section.
 int appStgCnt =
 ConfigurationManager.AppSettings.Count;
 string newKey = "NewKey" + appStgCnt.ToString();

 string newValue = DateTime.Now.ToLongDateString() +
 " " + DateTime.Now.ToLongTimeString();

 config.AppSettings.Settings.Add(newKey, newValue);

 // Save the configuration file.
 customSection.SectionInformation.ForceSave = true;
 config.Save(ConfigurationSaveMode.Full);

 Console.WriteLine("Created configuration file: {0}",
 config.FilePath);
 }
 catch (ConfigurationErrorsException err)
 {
 Console.WriteLine("CreateConfigurationFile: {0}", err.ToString());
 }
 }

 // Show how to use the GetSection(string) method.
 static void GetCustomSection()
 {
 try
 {

 CustomSection customSection;

 // Get the current configuration file.
 System.Configuration.Configuration config =
 ConfigurationManager.OpenExeConfiguration(
 ConfigurationUserLevel.None) as Configuration;

 customSection =
 config.GetSection("CustomSection") as CustomSection;

 Console.WriteLine("Section name: {0}", customSection.Name);
 Console.WriteLine("Url: {0}", customSection.Url);
 Console.WriteLine("Port: {0}", customSection.Port);
 }
 catch (ConfigurationErrorsException err)
 {
 Console.WriteLine("Using GetSection(string): {0}", err.ToString());
 }
 }


 // Show how to use different modalities to save 
 // a configuration file.
 static void SaveConfigurationFile()
 {
 try
 {

 // Get the current configuration file.
 System.Configuration.Configuration config =
 ConfigurationManager.OpenExeConfiguration(
 ConfigurationUserLevel.None) as Configuration;

 // Save the full configuration file and force save even if the file was not modified.
 config.SaveAs("MyConfigFull.config", ConfigurationSaveMode.Full, true);
 Console.WriteLine("Saved config file as MyConfigFull.config using the mode: {0}",
 ConfigurationSaveMode.Full.ToString());

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

 // Save only the part of the configuration file that was modified. 
 config.SaveAs("MyConfigModified.config", ConfigurationSaveMode.Modified, true);
 Console.WriteLine("Saved config file as MyConfigModified.config using the mode: {0}",
 ConfigurationSaveMode.Modified.ToString());

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

 // Save the full configuration file.
 config.SaveAs("MyConfigMinimal.config");
 Console.WriteLine("Saved config file as MyConfigMinimal.config using the mode: {0}",
 ConfigurationSaveMode.Minimal.ToString());
 }
 catch (ConfigurationErrorsException err)
 {
 Console.WriteLine("SaveConfigurationFile: {0}", err.ToString());
 }
 }

 // Show how use the AppSettings and ConnectionStrings 
 // properties.
 static void GetSections(string section)
 {
 try
 {

 // Get the current configuration file.
 System.Configuration.Configuration config =
 ConfigurationManager.OpenExeConfiguration(
 ConfigurationUserLevel.None) as Configuration;

 // Get the selected section.
 switch (section)
 {
 case "appSettings":
 try
 {
 AppSettingsSection appSettings =
 config.AppSettings as AppSettingsSection;
 Console.WriteLine("Section name: {0}",
 appSettings.SectionInformation.SectionName);

 // Get the AppSettings section elements.
 Console.WriteLine();
 Console.WriteLine("Using AppSettings property.");
 Console.WriteLine("Application settings:");
 // Get the KeyValueConfigurationCollection 
 // from the configuration.
 KeyValueConfigurationCollection settings =
 config.AppSettings.Settings;

 // Display each KeyValueConfigurationElement.
 foreach (KeyValueConfigurationElement keyValueElement in settings)
 {
 Console.WriteLine("Key: {0}", keyValueElement.Key);
 Console.WriteLine("Value: {0}", keyValueElement.Value);
 Console.WriteLine();
 }
 }
 catch (ConfigurationErrorsException e)
 {
 Console.WriteLine("Using AppSettings property: {0}",
 e.ToString());
 }
 break;

 case "connectionStrings":
 ConnectionStringsSection
 conStrSection =
 config.ConnectionStrings as ConnectionStringsSection;
 Console.WriteLine("Section name: {0}",
 conStrSection.SectionInformation.SectionName);

 try
 {
 if (conStrSection.ConnectionStrings.Count != 0)
 {
 Console.WriteLine();
 Console.WriteLine("Using ConnectionStrings property.");
 Console.WriteLine("Connection strings:");

 // Get the collection elements.
 foreach (ConnectionStringSettings connection in
 conStrSection.ConnectionStrings)
 {
 string name = connection.Name;
 string provider = connection.ProviderName;
 string connectionString = connection.ConnectionString;

 Console.WriteLine("Name: {0}",
 name);
 Console.WriteLine("Connection string: {0}",
 connectionString);
 Console.WriteLine("Provider: {0}",
 provider);
 }
 }
 }
 catch (ConfigurationErrorsException e)
 {
 Console.WriteLine("Using ConnectionStrings property: {0}",
 e.ToString());
 }
 break;

 default:
 Console.WriteLine(
 "GetSections: Unknown section (0)", section);
 break;
 }
 }
 catch (ConfigurationErrorsException err)
 {
 Console.WriteLine("GetSections: (0)", err.ToString());
 }
 }

 // Show how to use the Configuration object properties 
 // to obtain configuration file information.
 static void GetConfigurationInformation()
 {
 try
 {

 // Get the current configuration file.
 System.Configuration.Configuration config =
 ConfigurationManager.OpenExeConfiguration(
 ConfigurationUserLevel.None) as Configuration;

 Console.WriteLine("Reading configuration information:");

 ContextInformation evalContext =
 config.EvaluationContext as ContextInformation;
 Console.WriteLine("Machine level: {0}",
 evalContext.IsMachineLevel.ToString());
 
 string filePath = config.FilePath;
 Console.WriteLine("File path: {0}", filePath);
 
 bool hasFile = config.HasFile;
 Console.WriteLine("Has file: {0}", hasFile.ToString());

 ConfigurationSectionGroupCollection
 groups = config.SectionGroups;
 Console.WriteLine("Groups: {0}", groups.Count.ToString());
 foreach (ConfigurationSectionGroup group in groups)
 {
 Console.WriteLine("Group Name: {0}", group.Name);
 // Console.WriteLine("Group Type: {0}", group.Type);
 }

 ConfigurationSectionCollection
 sections = config.Sections;
 Console.WriteLine("Sections: {0}", sections.Count.ToString());
 }
 catch (ConfigurationErrorsException err)
 {
 Console.WriteLine("GetConfigurationInformation: {0}",err.ToString());
 }
 }

#endregion 

#region Application Main
 //*** User Interaction Class ***//

 // Obtain user's input and provide feedback.
 // This class contains the application Main() function.
 // It calls the ConfigurationManager methods based 
 // on the user's selection.
 class ApplicationMain
 {
 // Display user's menu.
 public static void UserMenu()
 {
 string applicationName =
 Environment.GetCommandLineArgs()[0] + ".exe";
 StringBuilder buffer = new StringBuilder();

 buffer.AppendLine("Application: " + applicationName);
 buffer.AppendLine("Make your selection.");
 buffer.AppendLine("? -- Display help.");
 buffer.AppendLine("Q,q -- Exit the application.");
 
 buffer.Append("1 -- Instantiate the");
 buffer.AppendLine(" Configuration class.");

 buffer.Append("2 -- Use GetSection(string) to read ");
 buffer.AppendLine(" a custom section.");
 
 buffer.Append("3 -- Use SaveAs methods");
 buffer.AppendLine(" to save the configuration file.");

 buffer.Append("4 -- Use AppSettings property to read");
 buffer.AppendLine(" the appSettings section.");
 buffer.Append("5 -- Use ConnectionStrings property to read");
 buffer.AppendLine(" the connectionStrings section.");

 buffer.Append("6 -- Use Configuration class properties");
 buffer.AppendLine(" to obtain configuration information.");

 Console.Write(buffer.ToString());
 }

 // Obtain user's input and provide
 // feedback.
 static void Main(string[] args)
 {
 // Define user selection string.
 string selection;

 // Get the name of the application.
 string appName =
 Environment.GetCommandLineArgs()[0];

 // Get user selection.
 while (true)
 {

 UserMenu();
 Console.Write("> ");
 selection = Console.ReadLine();
 if (!string.IsNullOrEmpty(selection))
 break;
 }

 while (selection.ToLower() != "q")
 {
 // Process user's input.
 switch (selection)
 {
 case "1":
 // Show how to create an instance of the Configuration class.
 CreateConfigurationFile();
 break;

 case "2":
 // Show how to use GetSection(string) method.
 GetCustomSection();
 break;

 case "3":
 // Show how to use ConnectionStrings.
 SaveConfigurationFile();
 break;

 case "4":
 // Show how to use the AppSettings property.
 GetSections("appSettings");
 break;

 case "5":
 // Show how to use the ConnectionStrings property.
 GetSections("connectionStrings");
 break;

 case "6":
 // Show how to obtain configuration file information.
 GetConfigurationInformation();
 break;

 default:
 UserMenu();
 break;
 }
 Console.Write("> ");
 selection = Console.ReadLine();
 }
 }
 }
#endregion

}

Imports System.Text
Imports System.Configuration
Imports System.Globalization
Imports System.ComponentModel
Imports System.Collections.Specialized

' Before compiling this application, 
' remember to reference the System.Configuration assembly in your project. 
#Region "CustomSection class"

' Define a custom section. This class is used to
' populate the configuration file.
' It creates the following custom section:
' <CustomSection name="Contoso" url="http://www.contoso.com" port="8080" />.
Public NotInheritable Class CustomSection
 Inherits ConfigurationSection

 Public Sub New()

 End Sub


 <ConfigurationProperty("name", DefaultValue:="Contoso", IsRequired:=True, IsKey:=True)> _
 Public Property Name() As String
 Get
 Return CStr(Me("name"))
 End Get
 Set(ByVal value As String)
 Me("name") = value
 End Set
 End Property

 <ConfigurationProperty("url", DefaultValue:="http://www.contoso.com", IsRequired:=True), RegexStringValidator("\w+:\/\/[\w.]+\S*")> _
 Public Property Url() As String
 Get
 Return CStr(Me("url"))
 End Get
 Set(ByVal value As String)
 Me("url") = value
 End Set
 End Property

 <ConfigurationProperty("port", DefaultValue:=CInt(8080), IsRequired:=False), IntegerValidator(MinValue:=0, MaxValue:=8080, ExcludeRange:=False)> _
 Public Property Port() As Integer
 Get
 Return CInt(Fix(Me("port")))
 End Get
 Set(ByVal value As Integer)
 Me("port") = value
 End Set
 End Property



End Class

#End Region

#Region "Using Configuration Class"
Friend Class UsingConfigurationClass

 ' Show how to create an instance of the Configuration class
 ' that represents this application configuration file. 
 Public Shared Sub CreateConfigurationFile()
 Try

 ' Create a custom configuration section.
 Dim customSection As New CustomSection()

 ' Get the current configuration file.
 Dim config As System.Configuration.Configuration = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None)

 ' Create the section entry 
 ' in <configSections> and the 
 ' related target section in <configuration>.
 If config.Sections("CustomSection") Is Nothing Then
 config.Sections.Add("CustomSection", customSection)
 End If

 ' Create and add an entry to appSettings section.

 Dim conStringname As String = "LocalSqlServer"
 Dim conString As String = "data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|aspnetdb.mdf;User Instance=true"
 Dim providerName As String = "System.Data.SqlClient"

 Dim connStrSettings As New ConnectionStringSettings()
 connStrSettings.Name = conStringname
 connStrSettings.ConnectionString = conString
 connStrSettings.ProviderName = providerName

 config.ConnectionStrings.ConnectionStrings.Add(connStrSettings)

 ' Add an entry to appSettings section.
 Dim appStgCnt As Integer = ConfigurationManager.AppSettings.Count
 Dim newKey As String = "NewKey" & appStgCnt.ToString()

 Dim newValue As String = Date.Now.ToLongDateString() & " " & Date.Now.ToLongTimeString()

 config.AppSettings.Settings.Add(newKey, newValue)

 ' Save the configuration file.
 customSection.SectionInformation.ForceSave = True
 config.Save(ConfigurationSaveMode.Full)

 Console.WriteLine("Created configuration file: {0}", config.FilePath)

 Catch err As ConfigurationErrorsException
 Console.WriteLine("CreateConfigurationFile: {0}", err.ToString())
 End Try

 End Sub

 ' Show how to use the GetSection(string) method.
 Public Shared Sub GetCustomSection()
 Try

 Dim customSection As CustomSection

 ' Get the current configuration file.
 Dim config As System.Configuration.Configuration = TryCast(ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None), Configuration)

 customSection = TryCast(config.GetSection("CustomSection"), CustomSection)

 Console.WriteLine("Section name: {0}", customSection.Name)
 Console.WriteLine("Url: {0}", customSection.Url)
 Console.WriteLine("Port: {0}", customSection.Port)

 Catch err As ConfigurationErrorsException
 Console.WriteLine("Using GetSection(string): {0}", err.ToString())
 End Try

 End Sub


 ' Show how to use different modalities to save 
 ' a configuration file.
 Public Shared Sub SaveConfigurationFile()
 Try

 ' Get the current configuration file.
 Dim config As System.Configuration.Configuration = TryCast(ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None), Configuration)

 ' Save the full configuration file and force save even if the file was not modified.
 config.SaveAs("MyConfigFull.config", ConfigurationSaveMode.Full, True)
 Console.WriteLine("Saved config file as MyConfigFull.config using the mode: {0}", ConfigurationSaveMode.Full.ToString())

 config = TryCast(ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None), Configuration)

 ' Save only the part of the configuration file that was modified. 
 config.SaveAs("MyConfigModified.config", ConfigurationSaveMode.Modified, True)
 Console.WriteLine("Saved config file as MyConfigModified.config using the mode: {0}", ConfigurationSaveMode.Modified.ToString())

 config = TryCast(ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None), Configuration)

 ' Save the full configuration file.
 config.SaveAs("MyConfigMinimal.config")
 Console.WriteLine("Saved config file as MyConfigMinimal.config using the mode: {0}", ConfigurationSaveMode.Minimal.ToString())

 Catch err As ConfigurationErrorsException
 Console.WriteLine("SaveConfigurationFile: {0}", err.ToString())
 End Try

 End Sub


 ' Show how use the AppSettings and ConnectionStrings 
 ' properties.
 Public Shared Sub GetSections(ByVal section As String)
 Try

 ' Get the current configuration file.
 Dim config As System.Configuration.Configuration = TryCast(ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None), Configuration)

 ' Get the selected section.
 Select Case section
 Case "appSettings"
 Try
 Dim appSettings As AppSettingsSection = TryCast(config.AppSettings, AppSettingsSection)
 Console.WriteLine("Section name: {0}", appSettings.SectionInformation.SectionName)

 ' Get the AppSettings section elements.
 Console.WriteLine()
 Console.WriteLine("Using AppSettings property.")
 Console.WriteLine("Application settings:")
 ' Get the KeyValueConfigurationCollection 
 ' from the configuration.
 Dim settings As KeyValueConfigurationCollection = config.AppSettings.Settings

 ' Display each KeyValueConfigurationElement.
 For Each keyValueElement As KeyValueConfigurationElement In settings
 Console.WriteLine("Key: {0}", keyValueElement.Key)
 Console.WriteLine("Value: {0}", keyValueElement.Value)
 Console.WriteLine()
 Next keyValueElement
 Catch e As ConfigurationErrorsException
 Console.WriteLine("Using AppSettings property: {0}", e.ToString())
 End Try

 Case "connectionStrings"
 Dim conStrSection As ConnectionStringsSection = TryCast(config.ConnectionStrings, ConnectionStringsSection)
 Console.WriteLine("Section name: {0}", conStrSection.SectionInformation.SectionName)

 Try
 If conStrSection.ConnectionStrings.Count <> 0 Then
 Console.WriteLine()
 Console.WriteLine("Using ConnectionStrings property.")
 Console.WriteLine("Connection strings:")

 ' Get the collection elements.
 For Each connection As ConnectionStringSettings In conStrSection.ConnectionStrings
 Dim name As String = connection.Name
 Dim provider As String = connection.ProviderName
 Dim connectionString As String = connection.ConnectionString

 Console.WriteLine("Name: {0}", name)
 Console.WriteLine("Connection string: {0}", connectionString)
 Console.WriteLine("Provider: {0}", provider)
 Next connection
 End If
 Catch e As ConfigurationErrorsException
 Console.WriteLine("Using ConnectionStrings property: {0}", e.ToString())
 End Try

 Case Else
 Console.WriteLine("GetSections: Unknown section (0)", section)
 End Select

 Catch err As ConfigurationErrorsException
 Console.WriteLine("GetSections: (0)", err.ToString())
 End Try

 End Sub

 ' Show how to use the Configuration object properties 
 ' to obtain configuration file information.
 Public Shared Sub GetConfigurationInformation()
 Try

 ' Get the current configuration file.
 Dim config As System.Configuration.Configuration = TryCast(ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None), Configuration)

 Console.WriteLine("Reading configuration information:")

 Dim evalContext As ContextInformation = TryCast(config.EvaluationContext, ContextInformation)
 Console.WriteLine("Machine level: {0}", evalContext.IsMachineLevel.ToString())

 Dim filePath As String = config.FilePath
 Console.WriteLine("File path: {0}", filePath)

 Dim hasFile As Boolean = config.HasFile
 Console.WriteLine("Has file: {0}", hasFile.ToString())


 Dim groups As ConfigurationSectionGroupCollection = config.SectionGroups
 Console.WriteLine("Groups: {0}", groups.Count.ToString())
 For Each group As ConfigurationSectionGroup In groups
 Console.WriteLine("Group Name: {0}", group.Name)
 ' Console.WriteLine("Group Type: {0}", group.Type);
 Next group


 Dim sections As ConfigurationSectionCollection = config.Sections
 Console.WriteLine("Sections: {0}", sections.Count.ToString())


 Catch err As ConfigurationErrorsException
 Console.WriteLine("GetConfigurationInformation: {0}", err.ToString())
 End Try

 End Sub
End Class

#End Region

#Region "Application Main"
'*** User Interaction Class ***//

' Obtain user's input and provide feedback.
' This class contains the application Main() function.
' It calls the ConfigurationManager methods based 
' on the user's selection.
Public Class ApplicationMain
 ' Display user's menu.
 Public Shared Sub UserMenu()
 Dim applicationName As String = Environment.GetCommandLineArgs()(0) & ".exe"
 Dim buffer As New StringBuilder()

 buffer.AppendLine("Application: " & applicationName)
 buffer.AppendLine("Please, make your selection.")
 buffer.AppendLine("? -- Display help.")
 buffer.AppendLine("Q,q -- Exit the application.")

 buffer.Append("1 -- Instantiate the")
 buffer.AppendLine(" Configuration class.")

 buffer.Append("2 -- Use GetSection(string) to read ")
 buffer.AppendLine(" a custom section.")

 buffer.Append("3 -- Use SaveAs methods")
 buffer.AppendLine(" to save the configuration file.")

 buffer.Append("4 -- Use AppSettings property to read")
 buffer.AppendLine(" the appSettings section.")
 buffer.Append("5 -- Use ConnectionStrings property to read")
 buffer.AppendLine(" the connectionStrings section.")

 buffer.Append("6 -- Use Configuration class properties")
 buffer.AppendLine(" to obtain configuration information.")

 Console.Write(buffer.ToString())
 End Sub

 ' Obtain user's input and provide
 ' feedback.
 Shared Sub Main(ByVal args() As String)
 ' Define user selection string.
 Dim selection As String

 ' Get the name of the application.
 Dim appName As String = Environment.GetCommandLineArgs()(0)


 ' Get user selection.
 Do

 UserMenu()
 Console.Write("> ")
 selection = Console.ReadLine()
 If selection <> String.Empty Then
 Exit Do
 End If
 Loop

 Do While selection.ToLower() <> "q"
 ' Process user's input.
 Select Case selection
 Case "1"
 ' Show how to create an instance of the Configuration class.
 UsingConfigurationClass.CreateConfigurationFile()

 Case "2"
 ' Show how to use GetSection(string) method.
 UsingConfigurationClass.GetCustomSection()

 Case "3"
 ' Show how to use ConnectionStrings.
 UsingConfigurationClass.SaveConfigurationFile()

 Case "4"
 ' Show how to use the AppSettings property.
 UsingConfigurationClass.GetSections("appSettings")

 Case "5"
 ' Show how to use the ConnectionStrings property.
 UsingConfigurationClass.GetSections("connectionStrings")

 Case "6"
 ' Show how to obtain configuration file information.
 UsingConfigurationClass.GetConfigurationInformation()


 Case Else
 UserMenu()
 End Select
 Console.Write("> ")
 selection = Console.ReadLine()
 Loop
 End Sub
End Class
#End Region

Remarks

Configuration settings are stored in a hierarchy of configuration files. The Configuration class instance represents the merged view of the configuration settings from all of the configuration files that apply to a specific physical entity, such as a computer, or to a logical entity, such as an application or a Web site. The logical entity can exist on the local computer or on a remote server. For information about configuration files, see Configuring Apps and ASP.NET Configuration Files.

When no configuration file exists for a specified entity, the Configuration object represents the default configuration settings as defined by the Machine.config file.

You can get a Configuration object by using the following classes:

• The ConfigurationManager class, if your entity is a client application.

• The WebConfigurationManager class, if your entity is a Web application.

The names of the methods that return a Configuration object begin with "Open".

You can also generate a configuration file that represents the configuration settings in a Configuration object. To do this, use one of the following methods:

• Call the Save method to create a new configuration file.

• Call the SaveAs method to generate a new configuration file at another location.

The names of the methods that create configuration files begin with "Save".

Notes to Inheritors

The Configuration class provides programmatic access for editing configuration files. You use one of the "Open" methods provided by the WebConfigurationManager class for Web applications or by the ConfigurationManager class for client applications. These methods return a Configuration object, which in turn provides the methods and properties that handle the underlying configuration files. You can access these files for reading or writing configuration information.

You use the GetSection(String) method or the GetSectionGroup(String) method to read configuration information. Note that 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, it is recommended that you use the GetSection method overloads for Web applications. For client application, use the GetSection(String) method.

These methods provide access to the cached configuration values for the current application, which has better performance than the Configuration class.

Note: If you use a static GetSection method that takes a path parameter, the path parameter must refer to the application in which the code is running, otherwise the parameter is ignored and configuration information for the currently running application is returned.

You use one of the Save methods to write configuration information. Note that 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.

See also

• ConfigurationSection
• ConfigurationManager
• WebConfigurationManager
• Administering ASP.NET Web Sites
• Configuration Files
• ASP.NET Configuration Files