IContainer Interface
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IContainer Interface

Provides functionality for containers. Containers are objects that logically contain zero or more components.

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

'Declaration
<ComVisibleAttribute(True)> _
Public Interface IContainer _
	Inherits IDisposable
'Usage
Dim instance As IContainer

Containers are objects that encapsulate and track zero or more components. In this context, containment refers to logical containment, not visual containment. You can use components and containers in a variety of scenarios, including scenarios that are both visual and not visual.

Notes to Implementers:

To be a container, the class must implement the IContainer interface, which supports methods for adding, removing, and retrieving components.

The following code example demonstrates how to implement the IContainer interface.

	'This code segment implements the IContainer interface.  The code segment  
	'containing the implementation of ISite and IComponent can be found in the documentation 
	'for those interfaces. 
	
	'Implement the LibraryContainer using the IContainer interface. 

Class LibraryContainer
    Implements IContainer
    Private m_bookList As ArrayList

    Public Sub New()
        m_bookList = New ArrayList()
    End Sub 

    Public Sub Add(ByVal book As IComponent) Implements IContainer.Add
        'The book will be added without creation of the ISite object.
        m_bookList.Add(book)
    End Sub 

    Public Sub Add(ByVal book As IComponent, ByVal ISNDNNum As String) Implements IContainer.Add

        Dim i As Integer 
        Dim curObj As IComponent

        For i = 0 To m_bookList.Count - 1
            curObj = CType(m_bookList(i), IComponent)
            If curObj.Site IsNot Nothing Then 
                If (curObj.Site.Name.Equals(ISNDNNum)) Then 
                    Throw New SystemException("The ISBN number already exists in the container")
                End If 
            End If 
        Next i

        Dim data As ISBNSite = New ISBNSite(Me, book)
        data.Name = ISNDNNum
        book.Site = data
        m_bookList.Add(book)

    End Sub 

    Public Sub Remove(ByVal book As IComponent) Implements IContainer.Remove
        Dim i As Integer 
        Dim curComp As BookComponent = CType(book, BookComponent)

        For i = 0 To m_bookList.Count - 1
            If (curComp.Equals(m_bookList(i)) = True) Then
                m_bookList.RemoveAt(i)
                Exit For 
            End If 
        Next i
    End Sub 


    Public ReadOnly Property Components() As ComponentCollection Implements IContainer.Components
        Get 
            Dim datalist(m_bookList.Count - 1) As IComponent

            m_bookList.CopyTo(datalist)
            Return New ComponentCollection(datalist)
        End Get 
    End Property 

    Public Overridable Sub Dispose() Implements IDisposable.Dispose
        Dim i As Integer 
        For i = 0 To m_bookList.Count - 1
            Dim curObj As IComponent = CType(m_bookList(i), IComponent)
            curObj.Dispose()
        Next i

        m_bookList.Clear()
    End Sub 

    Public Shared Sub Main()
        Dim cntrExmpl As LibraryContainer = New LibraryContainer()

        Try 
            Dim book1 As BookComponent = New BookComponent("Wizard's First Rule", "Terry Gooodkind")
            cntrExmpl.Add(book1, "0812548051")
            Dim book2 As BookComponent = New BookComponent("Stone of Tears", "Terry Gooodkind")
            cntrExmpl.Add(book2, "0812548094")
            Dim book3 As BookComponent = New BookComponent("Blood of the Fold", "Terry Gooodkind")
            cntrExmpl.Add(book3, "0812551478")
            Dim book4 As BookComponent = New BookComponent("The Soul of the Fire", "Terry Gooodkind")
            'This will generate an exception, because the ISBN already exists in the container.
            cntrExmpl.Add(book4, "0812551478")
        Catch e As SystemException
            Console.WriteLine("Error description: " + e.Message)
        End Try 

        Dim datalist As ComponentCollection = cntrExmpl.Components
        Dim denum As IEnumerator = datalist.GetEnumerator()

        While (denum.MoveNext())
            Dim cmp As BookComponent = CType(denum.Current, BookComponent)
            Console.WriteLine("Book Title: " + cmp.Title)
            Console.WriteLine("Book Author: " + cmp.Author)
            Console.WriteLine("Book ISBN: " + cmp.Site.Name)
        End While 
    End Sub 
End Class

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, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

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, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0

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