ComponentCollection Classe

Definizione

public ref class ComponentCollection : System::Collections::ReadOnlyCollectionBase

public ref class ComponentCollection

public class ComponentCollection : System.Collections.ReadOnlyCollectionBase

public class ComponentCollection

[System.Runtime.InteropServices.ComVisible(true)]
public class ComponentCollection : System.Collections.ReadOnlyCollectionBase

type ComponentCollection = class
    inherit ReadOnlyCollectionBase

type ComponentCollection = class

[<System.Runtime.InteropServices.ComVisible(true)>]
type ComponentCollection = class
    inherit ReadOnlyCollectionBase

Public Class ComponentCollection
Inherits ReadOnlyCollectionBase

Public Class ComponentCollection

Ereditarietà

Object

ReadOnlyCollectionBase

ComponentCollection

Ereditarietà

Object

ComponentCollection

Attributi

ComVisibleAttribute

Esempio

Nell'esempio di codice seguente viene illustrato come utilizzare un ComponentCollection oggetto per enumerare una raccolta di oggetti personalizzati BookComponent .

//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
{
    readonly ArrayList m_bookList = [];

    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 ArgumentException("The ISBN number already exists in the container");
                }
            }
        }

        book.Site = new ISBNSite(this, book) { Name = ISNDNNum };
        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()
    {
        LibraryContainer cntrExmpl = new();

        try
        {
            BookComponent book1 = new("Wizard's First Rule", "Terry Gooodkind");
            cntrExmpl.Add(book1, "0812548051");
            BookComponent book2 = new("Stone of Tears", "Terry Gooodkind");
            cntrExmpl.Add(book2, "0812548094");
            BookComponent book3 = new("Blood of the Fold", "Terry Gooodkind");
            cntrExmpl.Add(book3, "0812551478");
            BookComponent book4 = new("The Soul of the Fire", "Terry Gooodkind");
            //This will generate exception because the ISBN already exists in the container.
            cntrExmpl.Add(book4, "0812551478");
        }
        catch (ArgumentException e)
        {
            Console.WriteLine("Unable to add books: " + 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 ArgumentException("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 ArgumentException
            Console.WriteLine("Unable to add books: " + 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

Commenti

Questa raccolta eredita da ReadOnlyCollectionBase. L'unico modo per aggiungere IComponent oggetti a questa raccolta consiste nell'usare il costruttore della classe .

Questa raccolta fornisce due proprietà dell'indicizzatore, un indicizzatore di stringhe e un indicizzatore integer. La proprietà dell'indicizzatore di stringhe restituisce un componente nell'insieme in base al nome se la Site proprietà di un componente nell'insieme non null è e la NameSite proprietà della proprietà del componente corrisponde alla stringa specificata. La proprietà dell'indicizzatore integer restituisce l'oggetto IComponent in corrispondenza dell'indice dell'insieme specificato. Il CopyTo metodo copia il contenuto dell'insieme in una matrice specificata, iniziando a scrivere nella matrice in corrispondenza dell'indice specificato.

Vedi anche

• IComponent