ComponentCollection ComponentCollection ComponentCollection ComponentCollection Class

Definition

Provides a read-only container for a collection of IComponent objects.

public ref class ComponentCollection : System::Collections::ReadOnlyCollectionBase
[System.Runtime.InteropServices.ComVisible(true)]
public class ComponentCollection : System.Collections.ReadOnlyCollectionBase
type ComponentCollection = class
    inherit ReadOnlyCollectionBase
Public Class ComponentCollection
Inherits ReadOnlyCollectionBase
Inheritance
ComponentCollectionComponentCollectionComponentCollectionComponentCollection
Attributes

Examples

The following code example demonstrates how to use a ComponentCollection to enumerate a collection of custom BookComponent objects.

 //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.
 ref class LibraryContainer: public IContainer
 {
 private:
    ArrayList^ m_bookList;

 public:
    LibraryContainer()
    {
       m_bookList = gcnew ArrayList;
    }

    virtual void Add( IComponent^ book )
    {
       
       //The book will be added without creation of the ISite object.
       m_bookList->Add( book );
    }

    virtual void Add( IComponent^ book, String^ ISNDNNum )
    {
       for ( int i = 0; i < m_bookList->Count; ++i )
       {
          IComponent^ curObj = static_cast<IComponent^>(m_bookList->default[ i ]);
          if ( curObj->Site != nullptr )
          {
             if ( curObj->Site->Name->Equals( ISNDNNum ) )
                            throw gcnew SystemException( "The ISBN number already exists in the container" );
          }

       }
       ISBNSite^ data = gcnew ISBNSite( this,book );
       data->Name = ISNDNNum;
       book->Site = data;
       m_bookList->Add( book );
    }

    virtual void Remove( IComponent^ book )
    {
       for ( int i = 0; i < m_bookList->Count; ++i )
       {
          if ( book->Equals( m_bookList->default[ i ] ) )
          {
             m_bookList->RemoveAt( i );
             break;
          }

       }
    }


    property ComponentCollection^ Components 
    {
       virtual ComponentCollection^ get() 
       {
          array<IComponent^>^datalist = gcnew array<BookComponent^>(m_bookList->Count);
          m_bookList->CopyTo( datalist );
          return gcnew ComponentCollection( datalist );
       }

    }

    ~LibraryContainer()
    {
       for ( int i = 0; i < m_bookList->Count; ++i )
       {
          IComponent^ curObj = static_cast<IComponent^>(m_bookList->default[ i ]);
          delete curObj;

       }
       m_bookList->Clear();
    }



 };



 [STAThreadAttribute]
 int main()
    {
       LibraryContainer^ cntrExmpl = gcnew LibraryContainer;
       try
       {
          BookComponent^ book1 = gcnew BookComponent( "Wizard's First Rule","Terry Gooodkind" );
          cntrExmpl->Add( book1, "0812548051" );
          BookComponent^ book2 = gcnew BookComponent( "Stone of Tears","Terry Gooodkind" );
          cntrExmpl->Add( book2, "0812548094" );
          BookComponent^ book3 = gcnew BookComponent( "Blood of the Fold","Terry Gooodkind" );
          cntrExmpl->Add( book3, "0812551478" );
          BookComponent^ book4 = gcnew 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: {0}", e->Message );
       }

       ComponentCollection^ datalist = cntrExmpl->Components;
       IEnumerator^ denum = datalist->GetEnumerator();
       while ( denum->MoveNext() )
       {
          BookComponent^ cmp = static_cast<BookComponent^>(denum->Current);
          Console::WriteLine( "Book Title: {0}", cmp->Title );
          Console::WriteLine(  "Book Author: {0}", cmp->Author );
          Console::WriteLine(  "Book ISBN: {0}", cmp->Site->Name );
       }

return 0;
    }

//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 : IContainer
{
	private ArrayList m_bookList;

	public LibraryContainer()
	{
		m_bookList = new ArrayList();
	}

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

	public virtual void Add(IComponent book, string ISNDNNum)
	{
		for(int i =0; i < m_bookList.Count; ++i)
		{
			IComponent curObj = (IComponent)m_bookList[i];
			if(curObj.Site != null)
			{
				if(curObj.Site.Name.Equals(ISNDNNum))
					throw new SystemException("The ISBN number already exists in the container"); 
			}
		}

		ISBNSite data = new ISBNSite(this, book);
		data.Name = ISNDNNum;
		book.Site = data;
		m_bookList.Add(book);
	}

	public virtual void Remove(IComponent book)
	{
		for(int i =0; i < m_bookList.Count; ++i)
		{				
			if(book.Equals(m_bookList[i]))
			{
				m_bookList.RemoveAt(i);
					break;
			}
		}
	}

	public ComponentCollection Components
	{
		get
		{
			IComponent[] datalist = new BookComponent[m_bookList.Count];
			m_bookList.CopyTo(datalist);
			return new ComponentCollection(datalist);
		}
	}

	public virtual void Dispose()
	{	
		for(int i =0; i < m_bookList.Count; ++i)
		{
			IComponent curObj = (IComponent)m_bookList[i];
			curObj.Dispose();
		}
		
		m_bookList.Clear();
	}

	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.Message);
		}

		ComponentCollection datalist =cntrExmpl.Components;
		IEnumerator denum = datalist.GetEnumerator();

		while(denum.MoveNext())
		{
			BookComponent cmp = (BookComponent)denum.Current;
			Console.WriteLine("Book Title: " + cmp.Title);
			Console.WriteLine("Book Author: " + cmp.Author);
			Console.WriteLine("Book ISBN: " + cmp.Site.Name);
		}
	}
}
	'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

Remarks

This collection inherits from ReadOnlyCollectionBase. The only way to add IComponent objects to this collection is to use the class constructor.

This collection provides two indexer properties, a string indexer and an integer indexer. The string indexer property returns a component in the collection by name if the Site property of a component in the collection is not null and the Name property of the Site property of the component matches the specified string. The integer indexer property returns the IComponent at the specified collection index. The CopyTo method copies the contents of the collection to a specified array, beginning writing to the array at the specified index.

Constructors

ComponentCollection(IComponent[]) ComponentCollection(IComponent[]) ComponentCollection(IComponent[]) ComponentCollection(IComponent[])

Initializes a new instance of the ComponentCollection class using the specified array of components.

Properties

Item[Int32] Item[Int32] Item[Int32] Item[Int32]

Gets the Component in the collection at the specified collection index.

Item[String] Item[String] Item[String] Item[String]

Gets any component in the collection matching the specified name.

Methods

CopyTo(IComponent[], Int32) CopyTo(IComponent[], Int32) CopyTo(IComponent[], Int32) CopyTo(IComponent[], Int32)

Copies the entire collection to an array, starting writing at the specified array index.

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

Returns a string that represents the current object.

(Inherited from Object)

Applies to

See Also