ConfigurationElementCollection Class

 

Represents a configuration element containing a collection of child elements.

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

System.Object
  System.Configuration.ConfigurationElement
    System.Configuration.ConfigurationElementCollection
      System.Configuration.ConnectionStringSettingsCollection
      System.Configuration.KeyValueConfigurationCollection
      System.Configuration.NameValueConfigurationCollection
      System.Configuration.ProviderSettingsCollection
      System.Configuration.SchemeSettingElementCollection
      System.Configuration.SettingElementCollection
      System.IdentityModel.Configuration.AudienceUriElementCollection
      System.IdentityModel.Configuration.IdentityConfigurationElementCollection
      System.IdentityModel.Configuration.SecurityTokenHandlerElementCollection
      System.IdentityModel.Configuration.SecurityTokenHandlerSetElementCollection
      System.IdentityModel.Services.Configuration.FederationConfigurationElementCollection
      System.Net.Configuration.AuthenticationModuleElementCollection
      System.Net.Configuration.BypassElementCollection
      System.Net.Configuration.ConnectionManagementElementCollection
      System.Net.Configuration.WebRequestModuleElementCollection
      System.Runtime.Caching.Configuration.MemoryCacheSettingsCollection
      System.Runtime.Serialization.Configuration.DeclaredTypeElementCollection
      System.Runtime.Serialization.Configuration.ParameterElementCollection
      System.Runtime.Serialization.Configuration.TypeElementCollection
      System.Security.Authentication.ExtendedProtection.Configuration.ServiceNameElementCollection
      System.ServiceModel.Activities.Tracking.Configuration.TrackingConfigurationCollection(Of TConfigurationElement)
      System.ServiceModel.Configuration.ServiceModelConfigurationElementCollection(Of ConfigurationElementType)
      System.ServiceModel.Routing.Configuration.BackupEndpointCollection
      System.ServiceModel.Routing.Configuration.BackupListCollection
      System.ServiceModel.Routing.Configuration.FilterElementCollection
      System.ServiceModel.Routing.Configuration.FilterTableCollection
      System.ServiceModel.Routing.Configuration.FilterTableEntryCollection
      System.ServiceModel.Routing.Configuration.NamespaceElementCollection
      System.Web.Configuration.AssemblyCollection
      System.Web.Configuration.AuthorizationRuleCollection
      System.Web.Configuration.BufferModesCollection
      System.Web.Configuration.BuildProviderCollection
      System.Web.Configuration.ClientTargetCollection
      System.Web.Configuration.CodeSubDirectoriesCollection
      System.Web.Configuration.CompilerCollection
      System.Web.Configuration.ConvertersCollection
      System.Web.Configuration.CustomErrorCollection
      System.Web.Configuration.EventMappingSettingsCollection
      System.Web.Configuration.ExpressionBuilderCollection
      System.Web.Configuration.FolderLevelBuildProviderCollection
      System.Web.Configuration.FormsAuthenticationUserCollection
      System.Web.Configuration.FullTrustAssemblyCollection
      System.Web.Configuration.HttpHandlerActionCollection
      System.Web.Configuration.HttpModuleActionCollection
      System.Web.Configuration.IgnoreDeviceFilterElementCollection
      System.Web.Configuration.NamespaceCollection
      System.Web.Configuration.OutputCacheProfileCollection
      System.Web.Configuration.PartialTrustVisibleAssemblyCollection
      System.Web.Configuration.ProfileGroupSettingsCollection
      System.Web.Configuration.ProfilePropertySettingsCollection
      System.Web.Configuration.ProfileSettingsCollection
      System.Web.Configuration.ProtocolCollection
      System.Web.Configuration.RuleSettingsCollection
      System.Web.Configuration.SqlCacheDependencyDatabaseCollection
      System.Web.Configuration.TagMapCollection
      System.Web.Configuration.TagPrefixCollection
      System.Web.Configuration.TransformerInfoCollection
      System.Web.Configuration.TrustLevelCollection
      System.Web.Configuration.UrlMappingCollection
      System.Web.Mobile.DeviceFilterElementCollection
      System.Web.Services.Configuration.ProtocolElementCollection
      System.Web.Services.Configuration.SoapExtensionTypeElementCollection
      System.Web.Services.Configuration.TypeElementCollection
      System.Web.Services.Configuration.WsiProfilesElementCollection
      System.Web.UI.MobileControls.ControlElementCollection
      System.Web.UI.MobileControls.DeviceElementCollection
      System.Workflow.Runtime.Configuration.WorkflowRuntimeServiceElementCollection
      System.Xml.Serialization.Configuration.SchemaImporterExtensionElementCollection

Public MustInherit Class ConfigurationElementCollection
	Inherits ConfigurationElement
	Implements ICollection, IEnumerable

NameDescription
System_CAPS_protmethodConfigurationElementCollection()

Initializes a new instance of the ConfigurationElementCollection class.

System_CAPS_protmethodConfigurationElementCollection(IComparer)

Creates a new instance of the ConfigurationElementCollection class.

NameDescription
System_CAPS_protpropertyAddElementName

Gets or sets the name of the ConfigurationElement to associate with the add operation in the ConfigurationElementCollection when overridden in a derived class.

System_CAPS_protpropertyClearElementName

Gets or sets the name for the ConfigurationElement to associate with the clear operation in the ConfigurationElementCollection when overridden in a derived class.

System_CAPS_pubpropertyCollectionType

Gets the type of the ConfigurationElementCollection.

System_CAPS_pubpropertyCount

Gets the number of elements in the collection.

System_CAPS_pubpropertyCurrentConfiguration

Gets a reference to the top-level Configuration instance that represents the configuration hierarchy that the current ConfigurationElement instance belongs to.(Inherited from ConfigurationElement.)

System_CAPS_pubpropertyElementInformation

Gets an ElementInformation object that contains the non-customizable information and functionality of the ConfigurationElement object. (Inherited from ConfigurationElement.)

System_CAPS_protpropertyElementName

Gets the name used to identify this collection of elements in the configuration file when overridden in a derived class.

System_CAPS_protpropertyElementProperty

Gets the ConfigurationElementProperty object that represents the ConfigurationElement object itself.(Inherited from ConfigurationElement.)

System_CAPS_pubpropertyEmitClear

Gets or sets a value that specifies whether the collection has been cleared.

System_CAPS_protpropertyEvaluationContext

Gets the ContextInformation object for the ConfigurationElement object.(Inherited from ConfigurationElement.)

System_CAPS_protpropertyHasContext

(Inherited from ConfigurationElement.)

System_CAPS_pubpropertyIsSynchronized

Gets a value indicating whether access to the collection is synchronized.

System_CAPS_protpropertyItem(ConfigurationProperty)

Gets or sets a property or attribute of this configuration element.(Inherited from ConfigurationElement.)

System_CAPS_protpropertyItem(String)

Gets or sets a property, attribute, or child element of this configuration element.(Inherited from ConfigurationElement.)

System_CAPS_pubpropertyLockAllAttributesExcept

Gets the collection of locked attributes.(Inherited from ConfigurationElement.)

System_CAPS_pubpropertyLockAllElementsExcept

Gets the collection of locked elements.(Inherited from ConfigurationElement.)

System_CAPS_pubpropertyLockAttributes

Gets the collection of locked attributes (Inherited from ConfigurationElement.)

System_CAPS_pubpropertyLockElements

Gets the collection of locked elements.(Inherited from ConfigurationElement.)

System_CAPS_pubpropertyLockItem

Gets or sets a value indicating whether the element is locked.(Inherited from ConfigurationElement.)

System_CAPS_protpropertyProperties

Gets the collection of properties.(Inherited from ConfigurationElement.)

System_CAPS_protpropertyRemoveElementName

Gets or sets the name of the ConfigurationElement to associate with the remove operation in the ConfigurationElementCollection when overridden in a derived class.

System_CAPS_pubpropertySyncRoot

Gets an object used to synchronize access to the ConfigurationElementCollection.

System_CAPS_protpropertyThrowOnDuplicate

Gets a value indicating whether an attempt to add a duplicate ConfigurationElement to the ConfigurationElementCollection will cause an exception to be thrown.

NameDescription
System_CAPS_protmethodBaseAdd(ConfigurationElement)

Adds a configuration element to the ConfigurationElementCollection.

System_CAPS_protmethodBaseAdd(ConfigurationElement, Boolean)

Adds a configuration element to the configuration element collection.

System_CAPS_protmethodBaseAdd(Int32, ConfigurationElement)

Adds a configuration element to the configuration element collection.

System_CAPS_protmethodBaseClear()

Removes all configuration element objects from the collection.

System_CAPS_protmethodBaseGet(Int32)

Gets the configuration element at the specified index location.

System_CAPS_protmethodBaseGet(Object)

Returns the configuration element with the specified key.

System_CAPS_protmethodBaseGetAllKeys()

Returns an array of the keys for all of the configuration elements contained in the ConfigurationElementCollection.

System_CAPS_protmethodBaseGetKey(Int32)

Gets the key for the ConfigurationElement at the specified index location.

System_CAPS_protmethodBaseIndexOf(ConfigurationElement)

Indicates the index of the specified ConfigurationElement.

System_CAPS_protmethodBaseIsRemoved(Object)

Indicates whether the ConfigurationElement with the specified key has been removed from the ConfigurationElementCollection.

System_CAPS_protmethodBaseRemove(Object)

Removes a ConfigurationElement from the collection.

System_CAPS_protmethodBaseRemoveAt(Int32)

Removes the ConfigurationElement at the specified index location.

System_CAPS_pubmethodCopyTo(ConfigurationElement(), Int32)

Copies the contents of the ConfigurationElementCollection to an array.

System_CAPS_protmethodCreateNewElement()

When overridden in a derived class, creates a new ConfigurationElement.

System_CAPS_protmethodCreateNewElement(String)

Creates a new ConfigurationElement when overridden in a derived class.

System_CAPS_protmethodDeserializeElement(XmlReader, Boolean)

Reads XML from the configuration file.(Inherited from ConfigurationElement.)

System_CAPS_pubmethodEquals(Object)

Compares the ConfigurationElementCollection to the specified object.(Overrides ConfigurationElement.Equals(Object).)

System_CAPS_protmethodFinalize()

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)

System_CAPS_protmethodGetElementKey(ConfigurationElement)

Gets the element key for a specified configuration element when overridden in a derived class.

System_CAPS_pubmethodGetEnumerator()

This API supports the product infrastructure and is not intended to be used directly from your code. Gets an IEnumerator which is used to iterate through the ConfigurationElementCollection.

System_CAPS_pubmethodGetHashCode()

Gets a unique value representing the ConfigurationElementCollection instance.(Overrides ConfigurationElement.GetHashCode().)

System_CAPS_protmethodGetTransformedAssemblyString(String)

Returns the transformed version of the specified assembly name. (Inherited from ConfigurationElement.)

System_CAPS_protmethodGetTransformedTypeString(String)

Returns the transformed version of the specified type name.(Inherited from ConfigurationElement.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_protmethodInit()

Sets the ConfigurationElement object to its initial state.(Inherited from ConfigurationElement.)

System_CAPS_protmethodInitializeDefault()

Used to initialize a default set of values for the ConfigurationElement object.(Inherited from ConfigurationElement.)

System_CAPS_protmethodIsElementName(String)

Indicates whether the specified ConfigurationElement exists in the ConfigurationElementCollection.

System_CAPS_protmethodIsElementRemovable(ConfigurationElement)

Indicates whether the specified ConfigurationElement can be removed from the ConfigurationElementCollection.

System_CAPS_protmethodIsModified()

Indicates whether this ConfigurationElementCollection has been modified since it was last saved or loaded when overridden in a derived class.(Overrides ConfigurationElement.IsModified().)

System_CAPS_pubmethodIsReadOnly()

Indicates whether the ConfigurationElementCollection object is read only.(Overrides ConfigurationElement.IsReadOnly().)

System_CAPS_protmethodListErrors(IList)

Adds the invalid-property errors in this ConfigurationElement object, and in all subelements, to the passed list.(Inherited from ConfigurationElement.)

System_CAPS_protmethodMemberwiseClone()

Creates a shallow copy of the current Object.(Inherited from Object.)

System_CAPS_protmethodOnDeserializeUnrecognizedAttribute(String, String)

Gets a value indicating whether an unknown attribute is encountered during deserialization.(Inherited from ConfigurationElement.)

System_CAPS_protmethodOnDeserializeUnrecognizedElement(String, XmlReader)

Causes the configuration system to throw an exception.(Overrides ConfigurationElement.OnDeserializeUnrecognizedElement(String, XmlReader).)

System_CAPS_protmethodOnRequiredPropertyNotFound(String)

Throws an exception when a required property is not found.(Inherited from ConfigurationElement.)

System_CAPS_protmethodPostDeserialize()

Called after deserialization.(Inherited from ConfigurationElement.)

System_CAPS_protmethodPreSerialize(XmlWriter)

Called before serialization.(Inherited from ConfigurationElement.)

System_CAPS_protmethodReset(ConfigurationElement)

Resets the ConfigurationElementCollection to its unmodified state when overridden in a derived class.(Overrides ConfigurationElement.Reset(ConfigurationElement).)

System_CAPS_protmethodResetModified()

Resets the value of the IsModified property to false when overridden in a derived class.(Overrides ConfigurationElement.ResetModified().)

System_CAPS_protmethodSerializeElement(XmlWriter, Boolean)

Writes the configuration data to an XML element in the configuration file when overridden in a derived class.(Overrides ConfigurationElement.SerializeElement(XmlWriter, Boolean).)

System_CAPS_protmethodSerializeToXmlElement(XmlWriter, String)

Writes the outer tags of this configuration element to the configuration file when implemented in a derived class.(Inherited from ConfigurationElement.)

System_CAPS_protmethodSetPropertyValue(ConfigurationProperty, Object, Boolean)

Sets a property to the specified value.(Inherited from ConfigurationElement.)

System_CAPS_protmethodSetReadOnly()

This API supports the product infrastructure and is not intended to be used directly from your code. Sets the IsReadOnly property for the ConfigurationElementCollection object and for all sub-elements.(Overrides ConfigurationElement.SetReadOnly().)

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_protmethodUnmerge(ConfigurationElement, ConfigurationElement, ConfigurationSaveMode)

This API supports the product infrastructure and is not intended to be used directly from your code. Reverses the effect of merging configuration information from different levels of the configuration hierarchy (Overrides ConfigurationElement.Unmerge(ConfigurationElement, ConfigurationElement, ConfigurationSaveMode).)

NameDescription
System_CAPS_pubinterfaceSystem_CAPS_privmethodICollection.CopyTo(Array, Int32)

Copies the ConfigurationElementCollection to an array.

NameDescription
System_CAPS_pubmethodAsParallel()

Overloaded. Enables parallelization of a query.(Defined by ParallelEnumerable.)

System_CAPS_pubmethodAsQueryable()

Overloaded. Converts an IEnumerable to an IQueryable.(Defined by Queryable.)

System_CAPS_pubmethodCast(Of TResult)()

Casts the elements of an IEnumerable to the specified type.(Defined by Enumerable.)

System_CAPS_pubmethodOfType(Of TResult)()

Filters the elements of an IEnumerable based on a specified type.(Defined by Enumerable.)

The ConfigurationElementCollection represents a collection of elements within a configuration file.

System_CAPS_noteNote

An element within a configuration file refers to a basic XML element or a section. A simple element is an XML tag with related attributes, if any. A simple element constitutes a section. Complex sections can contain one or more simple elements, a collection of elements, and other sections.

You use the ConfigurationElementCollection to work with a collection of ConfigurationElement objects. Implement this class to add collections of custom ConfigurationElement elements to a ConfigurationSection.

Notes to Implementers:

You can use a programmatic or a declarative (attributed) coding model to create a custom configuration element.

The programmatic model requires that for each element attribute you create a property to get and set its value, and that you add it to the internal property bag of the underlying ConfigurationElement base class.

The declarative model, also referred to as the attributed model, allows you to define an element attribute by using a property and configuring it with attributes. These attributes instruct the ASP.NET configuration system about the property types and their default values. ASP.NET can use reflection to obtain this information and then create the element property objects and perform the required initialization.

The following example shows how to use the ConfigurationElementCollection.

The first example consists of three classes: UrlsSection, UrlsCollection and UrlConfigElement.The UrlsSection class uses the ConfigurationCollectionAttribute to define a custom configuration section. This section contains a URL collection (defined by the UrlsCollection class) of URL elements (defined by the UrlConfigElement class).

Imports Microsoft.VisualBasic
Imports System
Imports System.Configuration

' Define a UrlsSection custom section that contains a 
' UrlsCollection collection of UrlConfigElement elements.
Public Class UrlsSection
    Inherits ConfigurationSection

    ' Declare the UrlsCollection collection property.
    <ConfigurationProperty("urls", IsDefaultCollection:=False), ConfigurationCollection(GetType(UrlsCollection), AddItemName:="add", ClearItemsName:="clear", RemoveItemName:="remove")>
    Public Property Urls() As UrlsCollection
        Get
            Dim urlsCollection As UrlsCollection = CType(MyBase.Item("urls"), UrlsCollection)

            Return urlsCollection
        End Get

        Set(ByVal value As UrlsCollection)
            Dim urlsCollection As UrlsCollection = value
        End Set

    End Property

    ' Create a new instance of the UrlsSection.
    ' This constructor creates a configuration element 
    ' using the UrlConfigElement default values.
    ' It assigns this element to the collection.
    Public Sub New()
        Dim url As New UrlConfigElement()
        Urls.Add(url)

    End Sub

End Class

' Define the UrlsCollection that contains the 
' UrlsConfigElement elements.
' This class shows how to use the ConfigurationElementCollection.
Public Class UrlsCollection
    Inherits System.Configuration.ConfigurationElementCollection


    Public Sub New()

    End Sub

    Public ReadOnly Property CollectionType() As ConfigurationElementCollectionType
        Get
            Return ConfigurationElementCollectionType.AddRemoveClearMap
        End Get
    End Property

    Protected Overloads Overrides Function CreateNewElement() As ConfigurationElement
        Return New UrlConfigElement()
    End Function

    Protected Overrides Function GetElementKey(ByVal element As ConfigurationElement) As Object
        Return (CType(element, UrlConfigElement)).Name
    End Function

    Default Public Shadows Property Item(ByVal index As Integer) As UrlConfigElement
        Get
            Return CType(BaseGet(index), UrlConfigElement)
        End Get
        Set(ByVal value As UrlConfigElement)
            If BaseGet(index) IsNot Nothing Then
                BaseRemoveAt(index)
            End If
            BaseAdd(value)
        End Set
    End Property

    Default Public Shadows ReadOnly Property Item(ByVal Name As String) As UrlConfigElement
        Get
            Return CType(BaseGet(Name), UrlConfigElement)
        End Get
    End Property

    Public Function IndexOf(ByVal url As UrlConfigElement) As Integer
        Return BaseIndexOf(url)
    End Function

    Public Sub Add(ByVal url As UrlConfigElement)
        BaseAdd(url)

        ' Your custom code goes here.

    End Sub

    Protected Overloads Sub BaseAdd(ByVal element As ConfigurationElement)
        BaseAdd(element, False)

        ' Your custom code goes here.

    End Sub

    Public Sub Remove(ByVal url As UrlConfigElement)
        If BaseIndexOf(url) >= 0 Then
            BaseRemove(url.Name)
            ' Your custom code goes here.
            Console.WriteLine("UrlsCollection: {0}", "Removed collection element!")
        End If
    End Sub

    Public Sub RemoveAt(ByVal index As Integer)
        BaseRemoveAt(index)

        ' Your custom code goes here.

    End Sub

    Public Sub Remove(ByVal name As String)
        BaseRemove(name)

        ' Your custom code goes here.

    End Sub

    Public Sub Clear()
        BaseClear()

        ' Your custom code goes here.
        Console.WriteLine("UrlsCollection: {0}", "Removed entire collection!")
    End Sub

End Class

' Define the UrlsConfigElement elements that are contained 
' by the UrlsCollection.
Public Class UrlConfigElement
    Inherits ConfigurationElement
    Public Sub New(ByVal name As String, ByVal url As String, ByVal port As Integer)
        Me.Name = name
        Me.Url = url
        Me.Port = port
    End Sub

    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(4040), 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

This second code example uses the classes specified before. You combine these two examples in a console application project.

Imports System.Configuration
Imports System.Text

Friend Class UsingConfigurationCollectionElement

    ' Create a custom section and save it in the 
    ' application configuration file.
    Private Shared Sub CreateCustomSection()
        Try

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

            ' Add the custom section to the application
            ' configuration file.
            Dim myUrlsSection As UrlsSection = CType(config.Sections("MyUrls"), UrlsSection)

            If myUrlsSection Is Nothing Then
                '  The configuration file does not contain the
                ' custom section yet. Create it.
                myUrlsSection = New UrlsSection()

                config.Sections.Add("MyUrls", myUrlsSection)

                ' Save the application configuration file.
                myUrlsSection.SectionInformation.ForceSave = True
                config.Save(ConfigurationSaveMode.Modified)
            Else
                If myUrlsSection.Urls.Count = 0 Then

                    ' The configuration file contains the
                    ' custom section but its element collection is empty.
                    ' Initialize the collection. 
                    Dim url As New UrlConfigElement()
                    myUrlsSection.Urls.Add(url)

                    ' Save the application configuration file.
                    myUrlsSection.SectionInformation.ForceSave = True
                    config.Save(ConfigurationSaveMode.Modified)
                End If
            End If


            Console.WriteLine("Created custom section in the application configuration file: {0}", config.FilePath)
            Console.WriteLine()

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

    End Sub

    Private Shared Sub ReadCustomSection()
        Try
            ' Get the application configuration file.
            Dim config As System.Configuration.Configuration = TryCast(ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None), Configuration)

            ' Read and display the custom section.
            Dim myUrlsSection As UrlsSection = TryCast(config.GetSection("MyUrls"), UrlsSection)

            If myUrlsSection Is Nothing Then
                Console.WriteLine("Failed to load UrlsSection.")
            Else
                Console.WriteLine("Collection elements contained in the custom section collection:")
                For i As Integer = 0 To myUrlsSection.Urls.Count - 1
                    Console.WriteLine("   Name={0} URL={1} Port={2}", myUrlsSection.Urls(i).Name, myUrlsSection.Urls(i).Url, myUrlsSection.Urls(i).Port)
                Next i
            End If

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

    End Sub

    ' Add an element to the custom section collection.
    ' This function uses the ConfigurationCollectionElement Add method.
    Private Shared Sub AddCollectionElement()
        Try

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


            ' Get the custom configuration section.
            Dim myUrlsSection As UrlsSection = TryCast(config.GetSection("MyUrls"), UrlsSection)


            ' Add the element to the collection in the custom section.
            If config.Sections("MyUrls") IsNot Nothing Then
                Dim urlElement As New UrlConfigElement()
                urlElement.Name = "Microsoft"
                urlElement.Url = "http://www.microsoft.com"
                urlElement.Port = 8080

                ' Use the ConfigurationCollectionElement Add method
                ' to add the new element to the collection.
                myUrlsSection.Urls.Add(urlElement)


                ' Save the application configuration file.
                myUrlsSection.SectionInformation.ForceSave = True
                config.Save(ConfigurationSaveMode.Modified)


                Console.WriteLine("Added collection element to the custom section in the configuration file: {0}", config.FilePath)
                Console.WriteLine()
            Else
                Console.WriteLine("You must create the custom section first.")
            End If

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

    End Sub

    ' Remove element from the custom section collection.
    ' This function uses one of the ConfigurationCollectionElement 
    ' overloaded Remove methods.
    Private Shared Sub RemoveCollectionElement()
        Try

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


            ' Get the custom configuration section.
            Dim myUrlsSection As UrlsSection = TryCast(config.GetSection("MyUrls"), UrlsSection)


            ' Remove the element from the custom section.
            If config.Sections("MyUrls") IsNot Nothing Then
                Dim urlElement As New UrlConfigElement()
                urlElement.Name = "Microsoft"
                urlElement.Url = "http://www.microsoft.com"
                urlElement.Port = 8080

                ' Use one of the ConfigurationCollectionElement Remove 
                ' overloaded methods to remove the element from the collection.
                myUrlsSection.Urls.Remove(urlElement)


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


                Console.WriteLine("Removed collection element from he custom section in the configuration file: {0}", config.FilePath)
                Console.WriteLine()
            Else
                Console.WriteLine("You must create the custom section first.")
            End If

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

    End Sub

    ' Remove the collection of elements from the custom section.
    ' This function uses the ConfigurationCollectionElement Clear method.
    Private Shared Sub ClearCollectionElements()
        Try

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


            ' Get the custom configuration section.
            Dim myUrlsSection As UrlsSection = TryCast(config.GetSection("MyUrls"), UrlsSection)


            ' Remove the collection of elements from the section.
            If config.Sections("MyUrls") IsNot Nothing Then
                myUrlsSection.Urls.Clear()


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


                Console.WriteLine("Removed collection of elements from he custom section in the configuration file: {0}", config.FilePath)
                Console.WriteLine()
            Else
                Console.WriteLine("You must create the custom section first.")
            End If

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

    End Sub

    Public Shared Sub UserMenu()
        Dim applicationName As String = Environment.GetCommandLineArgs()(0) & ".exe"
        Dim buffer As 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    -- Create a custom section that")
        buffer.AppendLine(" contains a collection of elements.")
        buffer.Append("2    -- Read the custom section that")
        buffer.AppendLine(" contains a collection of custom elements.")
        buffer.Append("3    -- Add a collection element to")
        buffer.AppendLine(" the custom section.")
        buffer.Append("4    -- Remove a collection element from")
        buffer.AppendLine(" the custom section.")
        buffer.Append("5    -- Clear the collection of elements from")
        buffer.AppendLine(" the custom section.")

        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"
                    ' Create a custom section and save it in the 
                    ' application configuration file.
                    CreateCustomSection()

                Case "2"
                    ' Read the custom section from the
                    ' application configuration file.
                    ReadCustomSection()

                Case "3"
                    ' Add a collection element to the
                    ' custom section.
                    AddCollectionElement()

                Case "4"
                    ' Remove a collection element from the
                    ' custom section.
                    RemoveCollectionElement()

                Case "5"
                    ' Clear the collection of elements from the
                    ' custom section.
                    ClearCollectionElements()

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

When you run the console application, an instance of the UrlsSection class is created and the following configuration elements are generated in the application configuration file:

<configuration>
    <configSections>
        <section name="MyUrls" type="UrlsSection, 
          ConfigurationElementCollection, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />
    </configSections>
    <MyUrls>
        <urls>
           <add name="Contoso" url="http://www.contoso.com" port="4040 />
        </urls>
    </MyUrls>
</configuration

.NET Framework
Available since 2.0

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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