ComponentCollection 类

定义

IComponent 对象的集合提供只读容器。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
继承
ComponentCollection
属性

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。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.

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 ReadOnlyCollectionBaseThis collection inherits from ReadOnlyCollectionBase. IComponent 对象添加到此集合的唯一方法是使用类构造函数。The only way to add IComponent objects to this collection is to use the class constructor.

此集合提供了两个索引器属性:一个字符串索引器和一个整数索引器。This collection provides two indexer properties, a string indexer and an integer indexer. 如果集合中某个组件的 Site 属性不 null,并且该组件的 Site 属性的 Name 属性与指定的字符串匹配,则 string 索引器属性按名称返回集合中的一个组件。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. Integer 索引器属性返回指定集合索引处的 IComponentThe integer indexer property returns the IComponent at the specified collection index. CopyTo 方法将集合的内容复制到指定的数组,并向数组中指定索引处开始写入。The CopyTo method copies the contents of the collection to a specified array, beginning writing to the array at the specified index.

构造函数

ComponentCollection(IComponent[])

使用指定的组件数组初始化 ComponentCollection 类的新实例。Initializes a new instance of the ComponentCollection class using the specified array of components.

属性

Count

获取包含在 ReadOnlyCollectionBase 实例中的元素数。Gets the number of elements contained in the ReadOnlyCollectionBase instance.

(继承自 ReadOnlyCollectionBase)
InnerList

获取 ReadOnlyCollectionBase 实例中包含的元素的列表。Gets the list of elements contained in the ReadOnlyCollectionBase instance.

(继承自 ReadOnlyCollectionBase)
Item[Int32]

获取集合中位于指定集合索引处的 ComponentGets the Component in the collection at the specified collection index.

Item[String]

获取集合中与指定的名称相匹配的任何组件。Gets any component in the collection matching the specified name.

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

Equals(Object)

确定指定的对象是否等于当前对象。Determines whether the specified object is equal to the current object.

(继承自 Object)
GetEnumerator()

返回循环访问 ReadOnlyCollectionBase 实例的枚举器。Returns an enumerator that iterates through the ReadOnlyCollectionBase instance.

(继承自 ReadOnlyCollectionBase)
GetHashCode()

用作默认哈希函数。Serves as the default hash function.

(继承自 Object)
GetType()

获取当前实例的 TypeGets the Type of the current instance.

(继承自 Object)
MemberwiseClone()

创建当前 Object 的浅表副本。Creates a shallow copy of the current Object.

(继承自 Object)
ToString()

返回一个表示当前对象的 string。Returns a string that represents the current object.

(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 ArrayCopies the entire ReadOnlyCollectionBase to a compatible one-dimensional Array, starting at the specified index of the target 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)。Gets a value indicating whether access to a ReadOnlyCollectionBase object is synchronized (thread safe).

(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。Gets an object that can be used to synchronize access to a ReadOnlyCollectionBase object.

(继承自 ReadOnlyCollectionBase)

扩展方法

Cast<TResult>(IEnumerable)

IEnumerable 的元素强制转换为指定的类型。Casts the elements of an IEnumerable to the specified type.

OfType<TResult>(IEnumerable)

根据指定类型筛选 IEnumerable 的元素。Filters the elements of an IEnumerable based on a specified type.

AsParallel(IEnumerable)

启用查询的并行化。Enables parallelization of a query.

AsQueryable(IEnumerable)

IEnumerable 转换为 IQueryableConverts an IEnumerable to an IQueryable.

适用于

另请参阅