ComponentCollection 类

定义

命名空间:

System.ComponentModel

程序集:

System.ComponentModel.Primitives.dll

Source:

ComponentCollection.cs

为 IComponent 对象的集合提供只读容器。

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

public class ComponentCollection : System.Collections.ReadOnlyCollectionBase

type ComponentCollection = class
    inherit ReadOnlyCollectionBase

Public Class ComponentCollection
Inherits ReadOnlyCollectionBase

继承

Object

ReadOnlyCollectionBase

ComponentCollection

示例

下面的代码示例演示如何使用 ComponentCollection 枚举自定义 BookComponent 对象的集合。

//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 ArgumentException("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 (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

注解

此集合继承自 ReadOnlyCollectionBase。 将 对象添加到 IComponent 此集合的唯一方法是使用 类构造函数。

此集合提供两个索引器属性：一个字符串索引器和一个整数索引器。 如果Site集合中某个组件的属性不是null，并且NameSite该组件的 属性与指定的字符串匹配，则字符串索引器属性按名称返回集合中的组件。 整数索引器属性返回 IComponent 指定集合索引处的 。 方法 CopyTo 将集合的内容复制到指定的数组，从指定索引处开始写入数组。

构造函数

ComponentCollection(IComponent[])

使用指定的组件数组初始化 ComponentCollection 类的新实例。

属性

Count	获取 ReadOnlyCollectionBase 实例中包含的元素数。 (继承自 ReadOnlyCollectionBase)
InnerList	获取 ReadOnlyCollectionBase 实例中包含的元素的列表。 (继承自 ReadOnlyCollectionBase)
Item[Int32]	获取集合中位于指定集合索引处的 Component。
Item[String]	获取集合中与指定的名称相匹配的任何组件。

方法

CopyTo(IComponent[], Int32)	将整个集合复制到数组中，从指定的数组索引处开始写入。
Equals(Object)	确定指定对象是否等于当前对象。 (继承自 Object)
GetEnumerator()	返回循环访问 ReadOnlyCollectionBase 实例的枚举器。 (继承自 ReadOnlyCollectionBase)
GetHashCode()	作为默认哈希函数。 (继承自 Object)
GetType()	获取当前实例的 Type。 (继承自 Object)
MemberwiseClone()	创建当前 Object 的浅表副本。 (继承自 Object)
ToString()	返回表示当前对象的字符串。 (继承自 Object)

显式接口实现

ICollection.CopyTo(Array, Int32)	从目标数组的指定索引处开始将整个 ReadOnlyCollectionBase 复制到兼容的一维 Array。 (继承自 ReadOnlyCollectionBase)
ICollection.IsSynchronized	获取一个值，该值指示对 ReadOnlyCollectionBase 对象的访问是否同步（线程安全）。 (继承自 ReadOnlyCollectionBase)
ICollection.SyncRoot	获取一个对象，该对象可用于同步对 ReadOnlyCollectionBase 对象的访问。 (继承自 ReadOnlyCollectionBase)

扩展方法

Cast<TResult>(IEnumerable)	将 IEnumerable 的元素强制转换为指定的类型。
OfType<TResult>(IEnumerable)	根据指定类型筛选 IEnumerable 的元素。
AsParallel(IEnumerable)	启用查询的并行化。
AsQueryable(IEnumerable)	将 IEnumerable 转换为 IQueryable。

另请参阅

• IComponent