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AppSettingsSection Class

Provides configuration system support for the appSettings configuration section. This class cannot be inherited.

System.Object
  System.Configuration.ConfigurationElement
    System.Configuration.ConfigurationSection
      System.Configuration.AppSettingsSection

Namespace:  System.Configuration
Assembly:  System.Configuration (in System.Configuration.dll)
public sealed class AppSettingsSection : ConfigurationSection

The AppSettingsSection type exposes the following members.

  Name Description
Public method AppSettingsSection Infrastructure. Initializes a new instance of the AppSettingsSection class.
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  Name Description
Public property CurrentConfiguration Gets a reference to the top-level Configuration instance that represents the configuration hierarchy that the current ConfigurationElement instance belongs to. (Inherited from ConfigurationElement.)
Public property ElementInformation Gets an ElementInformation object that contains the non-customizable information and functionality of the ConfigurationElement object. (Inherited from ConfigurationElement.)
Protected property ElementProperty Gets the ConfigurationElementProperty object that represents the ConfigurationElement object itself. (Inherited from ConfigurationElement.)
Protected property EvaluationContext Gets the ContextInformation object for the ConfigurationElement object. (Inherited from ConfigurationElement.)
Public property File Gets or sets a configuration file that provides additional settings or overrides the settings specified in the appSettings element.
Protected property Item[ConfigurationProperty] Gets or sets a property or attribute of this configuration element. (Inherited from ConfigurationElement.)
Protected property Item[String] Gets or sets a property, attribute, or child element of this configuration element. (Inherited from ConfigurationElement.)
Public property LockAllAttributesExcept Gets the collection of locked attributes. (Inherited from ConfigurationElement.)
Public property LockAllElementsExcept Gets the collection of locked elements. (Inherited from ConfigurationElement.)
Public property LockAttributes Gets the collection of locked attributes (Inherited from ConfigurationElement.)
Public property LockElements Gets the collection of locked elements. (Inherited from ConfigurationElement.)
Public property LockItem Gets or sets a value indicating whether the element is locked. (Inherited from ConfigurationElement.)
Protected property Properties Gets the collection of properties. (Inherited from ConfigurationElement.)
Public property SectionInformation Gets a SectionInformation object that contains the non-customizable information and functionality of the ConfigurationSection object. (Inherited from ConfigurationSection.)
Public property Settings Gets a collection of key/value pairs that contains application settings.
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  Name Description
Protected method DeserializeElement Reads XML from the configuration file. (Inherited from ConfigurationElement.)
Protected method DeserializeSection Infrastructure. Reads XML from the configuration file. (Inherited from ConfigurationSection.)
Public method Equals Compares the current ConfigurationElement instance to the specified object. (Inherited from ConfigurationElement.)
Protected method Finalize Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public method GetHashCode Gets a unique value representing the current ConfigurationElement instance. (Inherited from ConfigurationElement.)
Protected method GetRuntimeObject Returns a custom object when overridden in a derived class. (Inherited from ConfigurationSection.)
Protected method GetTransformedAssemblyString Returns the transformed version of the specified assembly name. (Inherited from ConfigurationElement.)
Protected method GetTransformedTypeString Returns the transformed version of the specified type name. (Inherited from ConfigurationElement.)
Public method GetType Gets the Type of the current instance. (Inherited from Object.)
Protected method Init Sets the ConfigurationElement object to its initial state. (Inherited from ConfigurationElement.)
Protected method InitializeDefault Used to initialize a default set of values for the ConfigurationElement object. (Inherited from ConfigurationElement.)
Protected method IsModified Indicates whether this configuration element has been modified since it was last saved or loaded when implemented in a derived class. (Inherited from ConfigurationSection.)
Public method IsReadOnly Gets a value indicating whether the ConfigurationElement object is read-only. (Inherited from ConfigurationElement.)
Protected method ListErrors Adds the invalid-property errors in this ConfigurationElement object, and in all subelements, to the passed list. (Inherited from ConfigurationElement.)
Protected method MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Protected method OnDeserializeUnrecognizedAttribute Gets a value indicating whether an unknown attribute is encountered during deserialization. (Inherited from ConfigurationElement.)
Protected method OnDeserializeUnrecognizedElement Gets a value indicating whether an unknown element is encountered during deserialization. (Inherited from ConfigurationElement.)
Protected method OnRequiredPropertyNotFound Throws an exception when a required property is not found. (Inherited from ConfigurationElement.)
Protected method PostDeserialize Called after deserialization. (Inherited from ConfigurationElement.)
Protected method PreSerialize Called before serialization. (Inherited from ConfigurationElement.)
Protected method Reset Resets the internal state of the ConfigurationElement object, including the locks and the properties collections. (Inherited from ConfigurationElement.)
Protected method ResetModified Resets the value of the IsModified method to false when implemented in a derived class. (Inherited from ConfigurationSection.)
Protected method SerializeElement Writes the contents of this configuration element to the configuration file when implemented in a derived class. (Inherited from ConfigurationElement.)
Protected method SerializeSection Infrastructure. Creates an XML string containing an unmerged view of the ConfigurationSection object as a single section to write to a file. (Inherited from ConfigurationSection.)
Protected method SerializeToXmlElement Writes the outer tags of this configuration element to the configuration file when implemented in a derived class. (Inherited from ConfigurationElement.)
Protected method SetPropertyValue Sets a property to the specified value. (Inherited from ConfigurationElement.)
Protected method SetReadOnly Sets the IsReadOnly property for the ConfigurationElement object and all subelements. (Inherited from ConfigurationElement.)
Protected method ShouldSerializeElementInTargetVersion Indicates whether the specified element should be serialized when the configuration object hierarchy is serialized for the specified target version of the .NET Framework. (Inherited from ConfigurationSection.)
Protected method ShouldSerializePropertyInTargetVersion Indicates whether the specified property should be serialized when the configuration object hierarchy is serialized for the specified target version of the .NET Framework. (Inherited from ConfigurationSection.)
Protected method ShouldSerializeSectionInTargetVersion Indicates whether the current ConfigurationSection instance should be serialized when the configuration object hierarchy is serialized for the specified target version of the .NET Framework. (Inherited from ConfigurationSection.)
Public method ToString Returns a string that represents the current object. (Inherited from Object.)
Protected method Unmerge Modifies the ConfigurationElement object to remove all values that should not be saved. (Inherited from ConfigurationElement.)
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The appSettings configuration section provides for key/value pairs of string values for an application. Rather than accessing these values by using an instance of an AppSettingsSection object, you should use the AppSettings property of the ConfigurationManager class or the AppSettings property of the WebConfigurationManager class.

The following example shows how to use the AppSettingsSection class in a console application. It reads and writes the key/value pairs that are contained by the appSettings section. It also shows how to access the File property of the AppSettingsSection class.

Note Note

Before you compile this code, add a reference in your project to System.Configuration.dll.


Imports System
Imports System.Collections.Specialized
Imports System.Configuration
Imports System.Text
Imports System.IO

' IMPORTANT: To compile this example, you must add to the project 
' a reference to the System.Configuration assembly.
'

Class UsingAppSettingsSection
#Region "UsingAppSettingsSection"

    ' This function shows how to use the File property of the
    ' appSettings section.
    ' The File property is used to specify an auxiliary 
    ' configuration file.
    ' Usually you create an auxiliary file off-line to store 
    ' additional settings that you can modify as needed without
    ' causing an application restart,as in the case of a Web 
    ' application.
    ' These settings are then added to the ones defined in the
    ' application configuration file.
    Private Shared Sub IntializeConfigurationFile()
        ' Create a set of unique key/value pairs to store in
        ' the appSettings section of an auxiliary configuration
        ' file.
        Dim time1 As String = String.Concat(Date.Now.ToLongDateString(), " ", Date.Now.ToLongTimeString())

        Dim time2 As String = String.Concat(Date.Now.ToLongDateString(), " ", New Date(2009, 6, 30).ToLongTimeString())

        Dim buffer() As String = {"<appSettings>", "<add key='AuxAppStg0' value='" & time1 & "'/>", "<add key='AuxAppStg1' value='" & time2 & "'/>", "</appSettings>"}

        ' Create an auxiliary configuration file and store the
        ' appSettings defined before.
        ' Note creating a file at run-time is just for demo 
        ' purposes to run this example.
        File.WriteAllLines("auxiliaryFile.config", buffer)

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

        ' Associate the auxiliary with the default
        ' configuration file. 
        Dim appSettings As System.Configuration.AppSettingsSection = config.AppSettings
        appSettings.File = "auxiliaryFile.config"

        ' Save the configuration file.
        config.Save(ConfigurationSaveMode.Modified)

        ' Force a reload in memory of the 
        ' changed section.
        ConfigurationManager.RefreshSection("appSettings")

    End Sub

    ' This function shows how to write a key/value
    ' pair to the appSettings section.
    Private Shared Sub WriteAppSettings()
        Try
            ' Get the application configuration file.
            Dim config As System.Configuration.Configuration = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None)

            ' Create a unique key/value pair to add to 
            ' the appSettings section.
            Dim keyName As String = "AppStg" & config.AppSettings.Settings.Count
            Dim value As String = String.Concat(Date.Now.ToLongDateString(), " ", Date.Now.ToLongTimeString())

            ' Add the key/value pair to the appSettings 
            ' section.
            ' config.AppSettings.Settings.Add(keyName, value);
            Dim appSettings As System.Configuration.AppSettingsSection = config.AppSettings
            appSettings.Settings.Add(keyName, value)

            ' Save the configuration file.
            config.Save(ConfigurationSaveMode.Modified)

            ' Force a reload in memory of the changed section.
            ' This to to read the section with the
            ' updated values.
            ConfigurationManager.RefreshSection("appSettings")

            Console.WriteLine("Added the following Key: {0} Value: {1} .", keyName, value)
        Catch e As Exception
            Console.WriteLine("Exception raised: {0}", e.Message)
        End Try
    End Sub

    ' This function shows how to read the key/value
    ' pairs (settings collection)contained in the 
    ' appSettings section.
    Private Shared Sub ReadAppSettings()
        Try

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

            ' Get the appSettings section.
            Dim appSettings As System.Configuration.AppSettingsSection = CType(config.GetSection("appSettings"), System.Configuration.AppSettingsSection)

            ' Get the auxiliary file name.
            Console.WriteLine("Auxiliary file: {0}", config.AppSettings.File)


            ' Get the settings collection (key/value pairs).
            If appSettings.Settings.Count <> 0 Then
                For Each key As String In appSettings.Settings.AllKeys
                    Dim value As String = appSettings.Settings(key).Value
                    Console.WriteLine("Key: {0} Value: {1}", key, value)
                Next key
            Else
                Console.WriteLine("The appSettings section is empty. Write first.")
            End If
        Catch e As Exception
            Console.WriteLine("Exception raised: {0}", e.Message)
        End Try
    End Sub

#End Region ' UsingAppSettingsSection


#Region "ApplicationMain"

    Shared Sub UserMenu()
        Dim buffer As New StringBuilder()

        buffer.AppendLine("Please, make your selection.")
        buffer.AppendLine("1    -- Write appSettings section.")
        buffer.AppendLine("2    -- Read  appSettings section.")
        buffer.AppendLine("?    -- Display help.")
        buffer.AppendLine("Q,q  -- Exit the application.")

        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)

        IntializeConfigurationFile()

        ' 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"
                    WriteAppSettings()

                Case "2"
                    ReadAppSettings()

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



using System;
using System.Collections.Specialized;
using System.Configuration;
using System.Text;
using System.IO;

// IMPORTANT: To compile this example, you must add to the project 
// a reference to the System.Configuration assembly.
//

class UsingAppSettingsSection
{
    #region UsingAppSettingsSection

    // This function shows how to use the File property of the
    // appSettings section.
    // The File property is used to specify an auxiliary 
    // configuration file.
    // Usually you create an auxiliary file off-line to store 
    // additional settings that you can modify as needed without
    // causing an application restart,as in the case of a Web 
    // application.
    // These settings are then added to the ones defined in the
    // application configuration file.
    static void  IntializeConfigurationFile()
    {
        // Create a set of unique key/value pairs to store in
        // the appSettings section of an auxiliary configuration
        // file.
        string time1 = String.Concat(DateTime.Now.ToLongDateString(),
                               " ", DateTime.Now.ToLongTimeString());

        string time2 = String.Concat(DateTime.Now.ToLongDateString(),
                               " ", new DateTime(2009, 06, 30).ToLongTimeString());

        string[] buffer = {"<appSettings>",
        "<add key='AuxAppStg0' value='" + time1 + "'/>", 
        "<add key='AuxAppStg1' value='" + time2 + "'/>",
        "</appSettings>"};

        // Create an auxiliary configuration file and store the
        // appSettings defined before.
        // Note creating a file at run-time is just for demo 
        // purposes to run this example.
        File.WriteAllLines("auxiliaryFile.config", buffer);

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

        // Associate the auxiliary with the default
        // configuration file. 
        System.Configuration.AppSettingsSection appSettings = config.AppSettings;
        appSettings.File = "auxiliaryFile.config";

        // Save the configuration file.
        config.Save(ConfigurationSaveMode.Modified);

        // Force a reload in memory of the 
        // changed section.
        ConfigurationManager.RefreshSection("appSettings");

    }

    // This function shows how to write a key/value
    // pair to the appSettings section.
    static void WriteAppSettings()
    {
        try
        {
            // Get the application configuration file.
            System.Configuration.Configuration config =
               ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);

            // Create a unique key/value pair to add to 
            // the appSettings section.
            string keyName = "AppStg" + config.AppSettings.Settings.Count;
            string value = string.Concat(DateTime.Now.ToLongDateString(),
                           " ", DateTime.Now.ToLongTimeString());

            // Add the key/value pair to the appSettings 
            // section.
            // config.AppSettings.Settings.Add(keyName, value);
            System.Configuration.AppSettingsSection appSettings = config.AppSettings;
            appSettings.Settings.Add(keyName, value);

            // Save the configuration file.
            config.Save(ConfigurationSaveMode.Modified);

            // Force a reload in memory of the changed section.
            // This to to read the section with the
            // updated values.
            ConfigurationManager.RefreshSection("appSettings");

            Console.WriteLine(
                "Added the following Key: {0} Value: {1} .", keyName, value);
        }
        catch (Exception e)
        {
            Console.WriteLine("Exception raised: {0}",
                e.Message);
        }
    }

    // This function shows how to read the key/value
    // pairs (settings collection)contained in the 
    // appSettings section.
    static void ReadAppSettings()
	{
        try
        {

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

            // Get the appSettings section.
            System.Configuration.AppSettingsSection appSettings =
                (System.Configuration.AppSettingsSection)config.GetSection("appSettings");

            // Get the auxiliary file name.
            Console.WriteLine("Auxiliary file: {0}", config.AppSettings.File);


            // Get the settings collection (key/value pairs).
            if (appSettings.Settings.Count != 0)
            {
                foreach (string key in appSettings.Settings.AllKeys)
                {
                    string value = appSettings.Settings[key].Value;
                    Console.WriteLine("Key: {0} Value: {1}", key, value);
                }
            }
            else
                Console.WriteLine("The appSettings section is empty. Write first.");
        }
        catch (Exception e)
        {
            Console.WriteLine("Exception raised: {0}",
                e.Message);
        }
	}

    #endregion UsingAppSettingsSection


    #region ApplicationMain

    // This class obtains user's input and provide feedback.
    // It contains the application Main.
    class ApplicationMain
    {
        // Display user's menu.
        public static void UserMenu()
        {
            StringBuilder buffer = new StringBuilder();

            buffer.AppendLine("Please, make your selection.");
            buffer.AppendLine("1    -- Write appSettings section.");
            buffer.AppendLine("2    -- Read  appSettings section.");
            buffer.AppendLine("?    -- Display help.");
            buffer.AppendLine("Q,q  -- Exit the application.");

            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];

            IntializeConfigurationFile();

            // Get user selection.
            while (true)
            {

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

            while (selection.ToLower() != "q")
            {
                // Process user's input.
                switch (selection)
                {
                    case "1":
                        WriteAppSettings();
                        break;

                    case "2":
                        ReadAppSettings();
                        break;

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



.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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