IOrderedDictionary Интерфейс

Определение

Представляет индексированную коллекцию пар «ключ-значение».

public interface class IOrderedDictionary : System::Collections::IDictionary
public interface IOrderedDictionary : System.Collections.IDictionary
type IOrderedDictionary = interface
    interface ICollection
    interface IEnumerable
    interface IDictionary
type IOrderedDictionary = interface
    interface IDictionary
    interface ICollection
    interface IEnumerable
Public Interface IOrderedDictionary
Implements IDictionary
Производный
Реализации

Примеры

В следующем примере кода демонстрируется реализация простого IOrderedDictionary на основе ArrayList класса. Реализованная функция IOrderedDictionary сохраняет имена в качестве ключей и фамилий в качестве значений, при этом добавлено требование, что каждое имя является уникальным.


#using <System.dll>

using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;

public ref class PeopleEnum : IDictionaryEnumerator
{
private:
    // Enumerators are positioned before the first element
    // until the first MoveNext() call.
    int position;
    ArrayList^ _people;

public:
    PeopleEnum(ArrayList^ list)
    {
        this->Reset();
        _people = list;
    }

    virtual bool MoveNext()
    {
        position++;
        return (position < _people->Count);
    }

    virtual void Reset()
    {
        position = -1;
    }

    virtual property Object^ Current
    {
        Object^ get()
        {
            try
            {
                return _people[position];
            }
            catch (IndexOutOfRangeException^)
            {
                throw gcnew InvalidOperationException();
            }
        }
    }

    virtual property DictionaryEntry Entry
    {
        DictionaryEntry get()
        {
            return (DictionaryEntry)(Current);
        }
    }

    virtual property Object^ Key
    {
        Object^ get()
        {
            try
            {
                return ((DictionaryEntry^)_people[position])->Key;
            }
            catch (IndexOutOfRangeException^)
            {
                throw gcnew InvalidOperationException();
            }
        }
    }

    virtual property Object^ Value
    {
        Object^ get()
        {
            try
            {
                return ((DictionaryEntry^)_people[position])->Value;
            }
            catch (IndexOutOfRangeException^)
            {
                throw gcnew InvalidOperationException();
            }
        }
    }
};

public ref class People : IOrderedDictionary
{
private:
    ArrayList^ _people;

public:
    People(int numItems)
    {
        _people = gcnew ArrayList(numItems);
    }

    int IndexOfKey(Object^ key)
    {
        for (int i = 0; i < _people->Count; i++)
        {
            if (((DictionaryEntry^)_people[i])->Key == key)
                return i;
        }

        // key not found, return -1.
        return -1;
    }

    virtual property Object^ default[Object^]
    {
        Object^ get(Object^ key)
        {
            return ((DictionaryEntry^)_people[IndexOfKey(key)])->Value;
        }
        void set(Object^ key, Object^ value)
        {
            _people[IndexOfKey(key)] = gcnew DictionaryEntry(key, value);
        }
    }

    // IOrderedDictionary Members
    virtual IDictionaryEnumerator^ GetEnumerator()
    {
        return gcnew PeopleEnum(_people);
    }

    virtual void Insert(int index, Object^ key, Object^ value)
    {
        if (IndexOfKey(key) != -1)
        {
            throw gcnew ArgumentException("An element with the same key already exists in the collection.");
        }
        _people->Insert(index, gcnew DictionaryEntry(key, value));
    }

    virtual void RemoveAt(int index)
    {
        _people->RemoveAt(index);
    }

    virtual property Object^ default[int]
    {
        Object^ get(int index)
        {
            return ((DictionaryEntry^)_people[index])->Value;
        }
        void set(int index, Object^ value)
        {
            Object^ key = ((DictionaryEntry^)_people[index])->Key;
            _people[index] = gcnew DictionaryEntry(key, value);
        }
    }

    // IDictionary Members

    virtual void Add(Object^ key, Object^ value)
    {
        if (IndexOfKey(key) != -1)
        {
            throw gcnew ArgumentException("An element with the same key already exists in the collection.");
        }
        _people->Add(gcnew DictionaryEntry(key, value));
    }

    virtual void Clear()
    {
        _people->Clear();
    }

    virtual bool Contains(Object^ key)
    {
        if (IndexOfKey(key) == -1)
        {
            return false;
        }
        else
        {
            return true;
        }
    }

    virtual property bool IsFixedSize
    {
        bool get()
        {
            return false;
        }
    }

    virtual property bool IsReadOnly
    {
        bool get()
        {
            return false;
        }
    }

    virtual property ICollection^ Keys
    {
        ICollection^ get()
        {
            ArrayList^ KeyCollection = gcnew ArrayList(_people->Count);
            for (int i = 0; i < _people->Count; i++)
            {
                KeyCollection->Add( ((DictionaryEntry^)_people[i])->Key );
            }
            return KeyCollection;
        }
    }

    virtual void Remove(Object^ key)
    {
        _people->RemoveAt(IndexOfKey(key));
    }

    virtual property ICollection^ Values
    {
        ICollection ^get()
        {
            ArrayList^ ValueCollection = gcnew ArrayList(_people->Count);
            for (int i = 0; i < _people->Count; i++)
            {
                ValueCollection->Add( ((DictionaryEntry^)_people[i])->Value );
            }
            return ValueCollection;
        }
    }

    // ICollection Members

    virtual void CopyTo(Array^ array, int index)
    {
        _people->CopyTo(array, index);
    }

    virtual property int Count
    {
        int get()
        {
            return _people->Count;
        }
    }

    virtual property bool IsSynchronized
    {
        bool get()
        {
            return _people->IsSynchronized;
        }
    }

    virtual property Object^ SyncRoot
    {
        Object^ get()
        {
            return _people->SyncRoot;
        }
    }

    // IEnumerable Members

    virtual IEnumerator^ IfcGetEnumerator() = IEnumerable::GetEnumerator
    {
        return (IEnumerator^) gcnew PeopleEnum(_people);
    }
};

class App
{
public:
    static void Main()
    {
        People^ peopleCollection = gcnew People(3);
        peopleCollection->Add("John", "Smith");
        peopleCollection->Add("Jim", "Johnson");
        peopleCollection->Add("Sue", "Rabon");

        Console::WriteLine("Displaying the entries in peopleCollection:");
        for each (DictionaryEntry^ de in peopleCollection)
        {
            Console::WriteLine("{0} {1}", de->Key, de->Value);
        }
        Console::WriteLine();
        Console::WriteLine("Displaying the entries in the modified peopleCollection:");
        peopleCollection["Jim"] = "Jackson";
        peopleCollection->Remove("Sue");
        peopleCollection->Insert(0, "Fred", "Anderson");

        for each (DictionaryEntry^ de in peopleCollection)
        {
            Console::WriteLine("{0} {1}", de->Key, de->Value);
        }

    }
};

int main()
{
    App::Main();
}
/* This code produces output similar to the following:
 *
 * Displaying the entries in peopleCollection:
 * John Smith
 * Jim Johnson
 * Sue Rabon
 *
 * Displaying the entries in the modified peopleCollection:
 * Fred Anderson
 * John Smith
 * Jim Jackson
 */
using System;
using System.Collections;
using System.Collections.Specialized;

public class People : IOrderedDictionary
{
    private ArrayList _people;

    public People(int numItems)
    {
        _people = new ArrayList(numItems);
    }

    public int IndexOfKey(object key)
    {
        for (int i = 0; i < _people.Count; i++)
        {
            if (((DictionaryEntry)_people[i]).Key == key)
                return i;
        }

        // key not found, return -1.
        return -1;
    }

    public object this[object key]
    {
        get
        {
            return ((DictionaryEntry)_people[IndexOfKey(key)]).Value;
        }
        set
        {
            _people[IndexOfKey(key)] = new DictionaryEntry(key, value);
        }
    }

    // IOrderedDictionary Members
    public IDictionaryEnumerator GetEnumerator()
    {
        return new PeopleEnum(_people);
    }

    public void Insert(int index, object key, object value)
    {
        if (IndexOfKey(key) != -1)
        {
            throw new ArgumentException("An element with the same key already exists in the collection.");
        }
        _people.Insert(index, new DictionaryEntry(key, value));
    }

    public void RemoveAt(int index)
    {
        _people.RemoveAt(index);
    }

    public object this[int index]
    {
        get
        {
            return ((DictionaryEntry)_people[index]).Value;
        }
        set
        {
            object key = ((DictionaryEntry)_people[index]).Key;
            _people[index] = new DictionaryEntry(key, value);
        }
    }
    // IDictionary Members

    public void Add(object key, object value)
    {
        if (IndexOfKey(key) != -1)
        {
            throw new ArgumentException("An element with the same key already exists in the collection.");
        }
        _people.Add(new DictionaryEntry(key, value));
    }

    public void Clear()
    {
        _people.Clear();
    }

    public bool Contains(object key)
    {
        if (IndexOfKey(key) == -1)
        {
            return false;
        }
        else
        {
            return true;
        }
    }

    public bool IsFixedSize
    {
        get
        {
            return false;
        }
    }

    public bool IsReadOnly
    {
        get
        {
            return false;
        }
    }

    public ICollection Keys
    {
        get
        {
            ArrayList KeyCollection = new ArrayList(_people.Count);
            for (int i = 0; i < _people.Count; i++)
            {
                KeyCollection.Add( ((DictionaryEntry)_people[i]).Key );
            }
            return KeyCollection;
        }
    }

    public void Remove(object key)
    {
        _people.RemoveAt(IndexOfKey(key));
    }

    public ICollection Values
    {
        get
        {
            ArrayList ValueCollection = new ArrayList(_people.Count);
            for (int i = 0; i < _people.Count; i++)
            {
                ValueCollection.Add( ((DictionaryEntry)_people[i]).Value );
            }
            return ValueCollection;
        }
    }

    // ICollection Members

    public void CopyTo(Array array, int index)
    {
        _people.CopyTo(array, index);
    }

    public int Count
    {
        get
        {
            return _people.Count;
        }
    }

    public bool IsSynchronized
    {
        get
        {
            return _people.IsSynchronized;
        }
    }

    public object SyncRoot
    {
        get
        {
            return _people.SyncRoot;
        }
    }

    // IEnumerable Members

    IEnumerator IEnumerable.GetEnumerator()
    {
        return new PeopleEnum(_people);
    }
}

public class PeopleEnum : IDictionaryEnumerator
{
    public ArrayList _people;

    // Enumerators are positioned before the first element
    // until the first MoveNext() call.
    int position = -1;

    public PeopleEnum(ArrayList list)
    {
        _people = list;
    }

    public bool MoveNext()
    {
        position++;
        return (position < _people.Count);
    }

    public void Reset()
    {
        position = -1;
    }

    public object Current
    {
        get
        {
            try
            {
                return _people[position];
            }
            catch (IndexOutOfRangeException)
            {
                throw new InvalidOperationException();
            }
        }
    }

    public DictionaryEntry Entry
    {
        get
        {
            return (DictionaryEntry)Current;
        }
    }

    public object Key
    {
        get
        {
            try
            {
                return ((DictionaryEntry)_people[position]).Key;
            }
            catch (IndexOutOfRangeException)
            {
                throw new InvalidOperationException();
            }
        }
    }

    public object Value
    {
        get
        {
            try
            {
                return ((DictionaryEntry)_people[position]).Value;
            }
            catch (IndexOutOfRangeException)
            {
                throw new InvalidOperationException();
            }
        }
    }
}

class App
{
    static void Main()
    {
        People peopleCollection = new People(3);
        peopleCollection.Add("John", "Smith");
        peopleCollection.Add("Jim", "Johnson");
        peopleCollection.Add("Sue", "Rabon");

        Console.WriteLine("Displaying the entries in peopleCollection:");
        foreach (DictionaryEntry de in peopleCollection)
        {
            Console.WriteLine("{0} {1}", de.Key, de.Value);
        }

        Console.WriteLine();
        Console.WriteLine("Displaying the entries in the modified peopleCollection:");
        peopleCollection["Jim"] = "Jackson";
        peopleCollection.Remove("Sue");
        peopleCollection.Insert(0, "Fred", "Anderson");

        foreach (DictionaryEntry de in peopleCollection)
        {
            Console.WriteLine("{0} {1}", de.Key, de.Value);
        }
    }
}
/* This code produces output similar to the following:
 *
 * Displaying the entries in peopleCollection:
 * John Smith
 * Jim Johnson
 * Sue Rabon
 *
 * Displaying the entries in the modified peopleCollection:
 * Fred Anderson
 * John Smith
 * Jim Jackson
 */
Imports System.Collections
Imports System.Collections.Specialized

Public Class People
    Implements IOrderedDictionary
    Private _people As ArrayList

    Public Sub New(ByVal numItems As Integer)
        _people = New ArrayList(numItems)
    End Sub

    Public Function IndexOfKey(ByVal key As Object) As Integer
        Dim i As Integer
        For i = 0 To _people.Count - 1
            If CType(_people(i), DictionaryEntry).Key = key Then
                Return i
            End If
        Next i

        ' key not found, return -1.
        Return -1
    End Function

    ' IOrderedDictionary Members
    Public Function GetEnumerator() As IDictionaryEnumerator _
        Implements IOrderedDictionary.GetEnumerator

        Return New PeopleEnum(_people)
    End Function

    Public Sub Insert(ByVal index As Integer, ByVal key As Object, _
        ByVal value As Object) Implements IOrderedDictionary.Insert

        If Not IndexOfKey(key) = -1 Then
            Throw New ArgumentException("An element with the same key already exists in the collection.")
        End If
        _people.Insert(index, New DictionaryEntry(key, value))
    End Sub

    Public Sub RemoveAt(ByVal index As Integer) _
        Implements IOrderedDictionary.RemoveAt

        _people.RemoveAt(index)
    End Sub

    Public Property Item(ByVal index As Integer) As Object _
        Implements IOrderedDictionary.Item

        Get
            Return CType(_people(index), DictionaryEntry).Value
        End Get
        Set(ByVal value As Object)
            Dim key As Object = CType(_people(index), DictionaryEntry).Key
            _people(index) = New DictionaryEntry(key, value)
        End Set
    End Property

    ' IDictionary Members
    Public Function IDictionaryGetEnumerator() As IDictionaryEnumerator _
    Implements IDictionary.GetEnumerator

        Return New PeopleEnum(_people)
    End Function

    Public Property Item(ByVal key As Object) As Object _
        Implements IDictionary.Item

        Get
            Return CType(_people(IndexOfKey(key)), DictionaryEntry).Value
        End Get
        Set(ByVal value)
            _people(IndexOfKey(key)) = New DictionaryEntry(key, value)
        End Set
    End Property


    Public Sub Add(ByVal key As Object, ByVal value As Object) _
        Implements IDictionary.Add

        If Not IndexOfKey(key) = -1 Then
            Throw New ArgumentException("An element with the same key already exists in the collection.")
        End If

        _people.Add(New DictionaryEntry(key, value))
    End Sub

    Public Sub Clear() Implements IDictionary.Clear
        _people.Clear()
    End Sub

    Public Function Contains(ByVal key As Object) As Boolean _
        Implements IDictionary.Contains

        If IndexOfKey(key) = -1 Then
            Return False
        Else
            Return True
        End If
    End Function

    Public ReadOnly Property IsFixedSize() As Boolean _
        Implements IDictionary.IsFixedSize

        Get
            Return False
        End Get
    End Property

    Public ReadOnly Property IsReadOnly() As Boolean _
        Implements IDictionary.IsReadOnly
        Get
            Return False
        End Get
    End Property

    Public ReadOnly Property Keys() As ICollection _
        Implements IDictionary.Keys
        Get
            Dim KeyCollection As ArrayList = New ArrayList(_people.Count)
            Dim i As Integer
            For i = 0 To _people.Count - 1
                KeyCollection.Add( CType(_people(i), DictionaryEntry).Key )
            Next i
            Return KeyCollection
        End Get
    End Property

    Public Sub Remove(ByVal key As Object) _
        Implements IDictionary.Remove

        _people.RemoveAt(IndexOfKey(key))
    End Sub

    Public ReadOnly Property Values() As ICollection _
        Implements IDictionary.Values
        Get
            Dim ValueCollection As ArrayList = New ArrayList(_people.Count)
            Dim i As Integer
            For i = 0 To _people.Count - 1
                ValueCollection.Add( CType(_people(i), DictionaryEntry).Value )
            Next i
            Return ValueCollection
        End Get
    End Property

    ' ICollection Members
    Public Sub CopyTo(ByVal array As Array, ByVal index As Integer) _
    Implements ICollection.CopyTo

        _people.CopyTo(Array, index)
    End Sub

    Public ReadOnly Property Count() As Integer _
        Implements ICollection.Count

        Get
            Return _people.Count
        End Get
    End Property

    Public ReadOnly Property IsSynchronized() As Boolean _
        Implements ICollection.IsSynchronized

        Get
            Return _people.IsSynchronized
        End Get
    End Property

    Public ReadOnly Property SyncRoot() As Object _
        Implements ICollection.SyncRoot

        Get
            Return _people.SyncRoot
        End Get
    End Property

    ' IEnumerable Members
    Public Function IEnumerableGetEnumerator() As IEnumerator _
        Implements IEnumerable.GetEnumerator

        Return New PeopleEnum(_people)
    End Function
End Class

Public Class PeopleEnum
    Implements IDictionaryEnumerator

    Public _people As ArrayList

    ' Enumerators are positioned before the first element
    ' until the first MoveNext() call.
    Dim position As Integer = -1

    Public Sub New(ByVal list As ArrayList)
        _people = list
    End Sub

    Public Function MoveNext() As Boolean _
        Implements IEnumerator.MoveNext

        position = position + 1
        Return (position < _people.Count)
    End Function

    Public Sub Reset() _
        Implements IEnumerator.Reset

        position = -1
    End Sub

    Public ReadOnly Property Current() As Object _
        Implements IEnumerator.Current

        Get
            Try
                Return _people(position)
            Catch e As IndexOutOfRangeException
                Throw New InvalidOperationException()
            End Try
        End Get
    End Property

    Public ReadOnly Property Entry() As DictionaryEntry _
        Implements IDictionaryEnumerator.Entry
        Get
            Return CType(Current, DictionaryEntry)
        End Get
    End Property

    Public ReadOnly Property Key() As Object _
        Implements IDictionaryEnumerator.Key

        Get
            Try
                Return CType(_people(position), DictionaryEntry).Key
            Catch e As IndexOutOfRangeException
                Throw New InvalidOperationException()
            End Try
        End Get
    End Property

    Public ReadOnly Property Value() As Object _
        Implements IDictionaryEnumerator.Value

        Get
            Try
                Return CType(_people(position), DictionaryEntry).Value
            Catch e As IndexOutOfRangeException
                Throw New InvalidOperationException()
            End Try
        End Get
    End Property
End Class

Class App
    Shared Sub Main()
        Dim peopleCollection As People = New People(3)
        peopleCollection.Add("John", "Smith")
        peopleCollection.Add("Jim", "Johnson")
        peopleCollection.Add("Sue", "Rabon")

        Console.WriteLine("Displaying the entries in peopleCollection:")
        Dim de As DictionaryEntry
        For Each de In peopleCollection
            Console.WriteLine("{0} {1}", de.Key, de.Value)
        Next

        Console.WriteLine()
        Console.WriteLine("Displaying the entries in the modified peopleCollection:")
        'peopleCollection("Jim") = "Jackson"
        peopleCollection.Remove("Sue")
        peopleCollection.Insert(0, "Fred", "Anderson")

        For Each de In peopleCollection
            Console.WriteLine("{0} {1}", de.Key, de.Value)
        Next
    End Sub
End Class
' This code produces output similar to the following:
' 
' Displaying the entries in peopleCollection:
' John Smith
' Jim Johnson
' Sue Rabon
' 
' Displaying the entries in the modified peopleCollection:
' Fred Anderson
' John Smith
' Jim Jackson

Комментарии

IOrderedDictionary доступ к элементам можно получить либо с помощью ключа, либо с помощью индекса.

Каждый элемент представляет собой пару "ключ-значение", хранящуюся в DictionaryEntry структуре.

Каждая пара должна иметь уникальный ключ, который не nullявляется, но значение может быть null и не должно быть уникальным. Интерфейс IOrderedDictionary позволяет перечислять содержащиеся ключи и значения, но не подразумевает определенный порядок сортировки.

Оператор foreach языка C# (For Eachв Visual Basic) возвращает объект типа элементов в коллекции. Так как каждый элемент IDictionary является парой "ключ-значение", тип элемента не является типом ключа или типа значения. Вместо этого используется DictionaryEntryтип элемента, как показано в следующем примере.

for each (DictionaryEntry de in myOrderedDictionary)
{
    //...
}
foreach (DictionaryEntry de in myOrderedDictionary)
{
    //...
}
For Each de In myOrderedDictionary
    '...
Next

Оператор foreach является оболочкой вокруг перечислителя, который позволяет только считывать данные из коллекции, а не записывать в нее.

Примечания для тех, кто реализует этот метод

Реализующий класс должен иметь средства для сравнения ключей.

Свойства

Count

Получает число элементов, содержащихся в интерфейсе ICollection.

(Унаследовано от ICollection)
IsFixedSize

Получает значение, показывающее, имеет ли объект IDictionary фиксированный размер.

(Унаследовано от IDictionary)
IsReadOnly

Получает значение, показывающее, является ли объект IDictionary доступным только для чтения.

(Унаследовано от IDictionary)
IsSynchronized

Возвращает значение, показывающее, является ли доступ к коллекции ICollection синхронизированным (потокобезопасным).

(Унаследовано от ICollection)
Item[Int32]

Возвращает или задает элемент по указанному индексу.

Item[Object]

Возвращает или задает элемент с указанным ключом.

(Унаследовано от IDictionary)
Keys

Получает объект ICollection, содержащий ключи объекта IDictionary.

(Унаследовано от IDictionary)
SyncRoot

Получает объект, с помощью которого можно синхронизировать доступ к коллекции ICollection.

(Унаследовано от ICollection)
Values

Получает объект ICollection, содержащий значения из объекта IDictionary.

(Унаследовано от IDictionary)

Методы

Add(Object, Object)

Добавляет элемент с указанными ключом и значением в объект IDictionary.

(Унаследовано от IDictionary)
Clear()

Удаляет все элементы из объекта IDictionary.

(Унаследовано от IDictionary)
Contains(Object)

Определяет, содержится ли элемент с указанным ключом в объекте IDictionary.

(Унаследовано от IDictionary)
CopyTo(Array, Int32)

Копирует элементы коллекции ICollection в массив Array, начиная с указанного индекса массива Array.

(Унаследовано от ICollection)
GetEnumerator()

Возвращает перечислитель, выполняющий итерацию элементов коллекции IOrderedDictionary.

Insert(Int32, Object, Object)

Вставляет пару "ключ-значение" в коллекцию по указанному индексу.

Remove(Object)

Удаляет элемент с указанным ключом из объекта IDictionary.

(Унаследовано от IDictionary)
RemoveAt(Int32)

Удаляет элемент по указанному индексу.

Методы расширения

Cast<TResult>(IEnumerable)

Приводит элементы объекта IEnumerable к заданному типу.

OfType<TResult>(IEnumerable)

Выполняет фильтрацию элементов объекта IEnumerable по заданному типу.

AsParallel(IEnumerable)

Позволяет осуществлять параллельный запрос.

AsQueryable(IEnumerable)

Преобразовывает коллекцию IEnumerable в объект IQueryable.

Применяется к

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