Was this page helpful?
Your feedback about this content is important. Let us know what you think.
Additional feedback?
1500 characters remaining
Export (0) Print
Expand All

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

/** @attribute ComVisibleAttribute(true) */ 
public interface IContainer extends IDisposable
ComVisibleAttribute(true) 
public interface IContainer extends IDisposable
Not applicable.

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

// 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 ArrayList mBookList;

    public LibraryContainer()
    {
        mBookList = new ArrayList();
    } //LibraryContainer

    public void Add(IComponent book)
    {
        // The book will be added without creation of the ISite object.
        mBookList.Add(book);
    } //Add

    public void Add(IComponent book, String isndNNum) throws SystemException
    {
        for (int i = 0; i < mBookList.get_Count(); ++i) {
            IComponent curObj = (IComponent)mBookList.get_Item(i);
            if (curObj.get_Site() != null) {
                if (curObj.get_Site().get_Name().Equals(isndNNum)) {
                    throw new SystemException(
                        "The ISBN number already exists in the container");
                }
            }
        }
        ISBNSite data = new ISBNSite(this, book);
        data.set_Name(isndNNum);
        book.set_Site(data);
        mBookList.Add(book);
    } //Add

    public void Remove(IComponent book)
    {
        for (int i = 0; i < mBookList.get_Count(); ++i) {
            if (book.Equals(mBookList.get_Item(i))) {
                mBookList.RemoveAt(i);
                break;
            }
        }
    } //Remove

    /** @property 
     */
    public ComponentCollection get_Components()
    {
        IComponent dataList[] = new BookComponent[mBookList.get_Count()];
        mBookList.CopyTo(dataList);
        return new ComponentCollection(dataList);
    } //get_Components

    public void Dispose()
    {
        for (int i = 0; i < mBookList.get_Count(); ++i) {
            IComponent curObj = (IComponent)mBookList.get_Item(i);
            curObj.Dispose();
        }
        mBookList.Clear();
    } //Dispose

    public static void main(String[] args)
    {
        LibraryContainer cntrExmpl = new LibraryContainer();
        try {
            BookComponent book1 = new BookComponent("Wizard's First Rule", 
                "Terry Gooodkind");
            cntrExmpl.Add(book1, "0812548051");
            BookComponent book2 = new BookComponent("Stone of Tears", 
                "Terry Gooodkind");
            cntrExmpl.Add(book2, "0812548094");
            BookComponent book3 = new BookComponent("Blood of the Fold", 
                "Terry Gooodkind");
            cntrExmpl.Add(book3, "0812551478");
            BookComponent book4 = new BookComponent("The Soul of the Fire", 
                "Terry Gooodkind");

            // This will generate exception because the ISBN already exists in 
            // the container.
            cntrExmpl.Add(book4, "0812551478");
        }
        catch (SystemException e) {
            Console.WriteLine("Error description: " + e.get_Message());
        }
        ComponentCollection dataList = cntrExmpl.get_Components();
        IEnumerator denum = dataList.GetEnumerator();

        while (denum.MoveNext()) {
            BookComponent cmp = (BookComponent)denum.get_Current();
            Console.WriteLine("Book Title: " + cmp.get_Title());
            Console.WriteLine("Book Author: " + cmp.get_Author());
            Console.WriteLine("Book ISBN: " + cmp.get_Site().get_Name());
        }
    } //main
} //LibraryContainer

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0

Community Additions

ADD
Show:
© 2015 Microsoft