IList Interface

Définition

Représente une collection non générique d'objets accessibles séparément par index.Represents a non-generic collection of objects that can be individually accessed by index.

public interface class IList : System::Collections::ICollection
[System.Runtime.InteropServices.ComVisible(true)]
public interface IList : System.Collections.ICollection
type IList = interface
    interface ICollection
    interface IEnumerable
Public Interface IList
Implements ICollection
Dérivé
Attributs
Implémente

Exemples

L’exemple suivant illustre l’implémentation de l' IList interface pour créer une liste simple, avec une liste de taille fixe.The following example demonstrates the implementation of the IList interface to create a simple list, fixed-size list.

using System;
using System.Collections;

class Program
{
    static void Main()
    {
        var test = new SimpleList();

        // Populate the List.
        Console.WriteLine("Populate the List");
        test.Add("one");
        test.Add("two");
        test.Add("three");
        test.Add("four");
        test.Add("five");
        test.Add("six");
        test.Add("seven");
        test.Add("eight");
        test.PrintContents();
        Console.WriteLine();

        // Remove elements from the list.
        Console.WriteLine("Remove elements from the list");
        test.Remove("six");
        test.Remove("eight");
        test.PrintContents();
        Console.WriteLine();

        // Add an element to the end of the list.
        Console.WriteLine("Add an element to the end of the list");
        test.Add("nine");
        test.PrintContents();
        Console.WriteLine();

        // Insert an element into the middle of the list.
        Console.WriteLine("Insert an element into the middle of the list");
        test.Insert(4, "number");
        test.PrintContents();
        Console.WriteLine();

        // Check for specific elements in the list.
        Console.WriteLine("Check for specific elements in the list");
        Console.WriteLine($"List contains \"three\": {test.Contains("three")}");
        Console.WriteLine($"List contains \"ten\": {test.Contains("ten")}");
    }
} 

class SimpleList : IList
{
    private object[] _contents = new object[8];
    private int _count;

    public SimpleList()
    {
        _count = 0;
    }

    // IList Members
    public int Add(object value)
    {
        if (_count < _contents.Length)
        {
            _contents[_count] = value;
            _count++;

            return (_count - 1);
        }

        return -1;
    }

    public void Clear()
    {
        _count = 0;
    }

    public bool Contains(object value)
    {
        for (int i = 0; i < Count; i++)
        {
            if (_contents[i] == value)
            {
                return true;
            }
        }
        return false;
    }

    public int IndexOf(object value)
    {
        for (int i = 0; i < Count; i++)
        {
            if (_contents[i] == value)
            {
                return i;
            }
        }
        return -1;
    }

    public void Insert(int index, object value)
    {
        if ((_count + 1 <= _contents.Length) && (index < Count) && (index >= 0))
        {
            _count++;

            for (int i = Count - 1; i > index; i--)
            {
                _contents[i] = _contents[i - 1];
            }
            _contents[index] = value;
        }
    }

    public bool IsFixedSize
    {
        get
        {
            return true;
        }
    }

    public bool IsReadOnly
    {
        get
        {
            return false;
        }
    }

    public void Remove(object value)
    {
        RemoveAt(IndexOf(value));
    }

    public void RemoveAt(int index)
    {
        if ((index >= 0) && (index < Count))
        {
            for (int i = index; i < Count - 1; i++)
            {
                _contents[i] = _contents[i + 1];
            }
            _count--;
        }
    }

    public object this[int index]
    {
        get
        {
            return _contents[index];
        }
        set
        {
            _contents[index] = value;
        }
    }

    // ICollection members.

    public void CopyTo(Array array, int index)
    {
        for (int i = 0; i < Count; i++)
        {
            array.SetValue(_contents[i], index++);
        }
    }

    public int Count
    {
        get
        {
            return _count;
        }
    }

    public bool IsSynchronized
    {
        get
        {
            return false;
        }
    }

    // Return the current instance since the underlying store is not
    // publicly available.
    public object SyncRoot
    {
        get
        {
            return this;
        }
    }

    // IEnumerable Members

    public IEnumerator GetEnumerator()
    {
        // Refer to the IEnumerator documentation for an example of
        // implementing an enumerator.
        throw new NotImplementedException("The method or operation is not implemented.");
    }

    public void PrintContents()
    {
        Console.WriteLine($"List has a capacity of {_contents.Length} and currently has {_count} elements.");
        Console.Write("List contents:");
        for (int i = 0; i < Count; i++)
        {
            Console.Write($" {_contents[i]}");
        }
        Console.WriteLine();
    }
}

// This code produces output similar to the following:
// Populate the List:
// List has a capacity of 8 and currently has 8 elements.
// List contents: one two three four five six seven eight
//
// Remove elements from the list:
// List has a capacity of 8 and currently has 6 elements.
// List contents: one two three four five seven
//
// Add an element to the end of the list:
// List has a capacity of 8 and currently has 7 elements.
// List contents: one two three four five seven nine
//
// Insert an element into the middle of the list:
// List has a capacity of 8 and currently has 8 elements.
// List contents: one two three four number five seven nine
//
// Check for specific elements in the list:
// List contains "three": True
// List contains "ten": False
Imports System.Collections

Public Class Program
    Shared Sub Main()

        Dim myList As New SimpleList()

        ' Populate the List.
        Console.WriteLine("Populate the List")
        myList.Add("one")
        myList.Add("two")
        myList.Add("three")
        myList.Add("four")
        myList.Add("five")
        myList.Add("six")
        myList.Add("seven")
        myList.Add("eight")
        myList.PrintContents()
        Console.WriteLine()

        ' Remove elements from the list.
        Console.WriteLine("Remove elements from the list")
        myList.Remove("six")
        myList.Remove("eight")
        myList.PrintContents()
        Console.WriteLine()

        ' Add an element to the end of the list.
        Console.WriteLine("Add an element to the end of the list")
        myList.Add("nine")
        myList.PrintContents()
        Console.WriteLine()

        ' Insert an element into the middle of the list.
        Console.WriteLine("Insert an element into the middle of the list")
        myList.Insert(4, "number")
        myList.PrintContents()
        Console.WriteLine()

        ' Check for specific elements in the list.
        Console.WriteLine("Check for specific elements in the list")
        Console.WriteLine($"List contains 'three': {myList.Contains("three")}")
        Console.WriteLine($"List contains 'ten': {myList.Contains("ten")}")
    End Sub
End Class

Public Class SimpleList
    Implements IList

    Private _contents(7) As Object
    Private _count As Integer

    Public Sub New()

        _count = 0
    End Sub

    ' IList members.
    Public Function Add(ByVal value As Object) As Integer Implements IList.Add
        If _count < _contents.Length Then
            _contents(_count) = value
            _count += 1

            Return _count - 1
        End If

        Return -1
    End Function

    Public Sub Clear() Implements IList.Clear
        _count = 0
    End Sub

    Public Function Contains(ByVal value As Object) As Boolean Implements IList.Contains
        For i As Integer = 0 To Count - 1
            If _contents(i) = value Then Return True
        Next

        Return False
    End Function

    Public Function IndexOf(ByVal value As Object) As Integer Implements IList.IndexOf
        For i As Integer = 0 To Count - 1
            If _contents(i) = value Then Return i
        Next
        Return -1
    End Function

    Public Sub Insert(ByVal index As Integer, ByVal value As Object) Implements IList.Insert

        If _count + 1 <= _contents.Length AndAlso index < Count AndAlso index >= 0 Then
            _count += 1

            For i As Integer = Count - 1 To index Step -1
                _contents(i) = _contents(i - 1)
            Next
            _contents(index) = value
        End If
    End Sub

    Public ReadOnly Property IsFixedSize() As Boolean Implements IList.IsFixedSize
        Get
            Return True
        End Get
    End Property

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

    Public Sub Remove(ByVal value As Object) Implements IList.Remove
        RemoveAt(IndexOf(value))
    End Sub

    Public Sub RemoveAt(ByVal index As Integer) Implements IList.RemoveAt

        if index >= 0 AndAlso index < Count Then
            for i As Integer = index To Count - 2
                _contents(i) = _contents(i + 1)
            Next
            _count -= 1
        End If
    End Sub

    Public Property Item(ByVal index As Integer) As Object Implements IList.Item
        Get
            Return _contents(index)
        End Get

        Set(ByVal value As Object)
            _contents(index) = value
        End Set
    End Property

    ' ICollection members.
    Public Sub CopyTo(ByVal array As Array, ByVal index As Integer) Implements ICollection.CopyTo
        For i As Integer = 0 To Count - 1
            array.SetValue(_contents(i), index)
            index += 1
        Next
    End Sub

    Public ReadOnly Property Count() As Integer Implements ICollection.Count
        Get
            Return _count
        End Get
    End Property

    Public ReadOnly Property IsSynchronized() As Boolean Implements ICollection.IsSynchronized
        Get
            Return False
        End Get
    End Property

    ' Return the current instance since the underlying store is not
    ' publicly available.
    Public ReadOnly Property SyncRoot() As Object Implements ICollection.SyncRoot
        Get
            Return Me
        End Get
    End Property

    ' IEnumerable members.
    Public Function GetEnumerator() As IEnumerator Implements IEnumerable.GetEnumerator

        ' Refer to the IEnumerator documentation for an example of
        ' implementing an enumerator.
        Throw New NotImplementedException("The method or operation is not implemented.")
    End Function

    Public Sub PrintContents()
        Console.WriteLine($"List has a capacity of {_contents.Length} and currently has {_count} elements.")
        Console.Write("List contents:")

        For i As Integer = 0 To Count - 1
            Console.Write($" {_contents(i)}")
        Next

        Console.WriteLine()
    End Sub
End Class

' This code produces output similar to the following:
' Populate the List:
' List has a capacity of 8 and currently has 8 elements.
' List contents: one two three four five six seven eight
'
' Remove elements from the list:
' List has a capacity of 8 and currently has 6 elements.
' List contents: one two three four five seven
'
' Add an element to the end of the list:
' List has a capacity of 8 and currently has 7 elements.
' List contents: one two three four five seven nine
'
' Insert an element into the middle of the list:
' List has a capacity of 8 and currently has 8 elements.
' List contents: one two three four number five seven nine
'
' Check for specific elements in the list:
' List contains "three": True
' List contains "ten": False

Remarques

IListest un descendant de l' ICollection interface et est l’interface de base de toutes les listes non génériques.IList is a descendant of the ICollection interface and is the base interface of all non-generic lists. IListles implémentations se répartissent en trois catégories: en lecture seule, à taille fixe et à taille variable.IList implementations fall into three categories: read-only, fixed-size, and variable-size. Un en lecture seule IList ne peut pas être modifié.A read-only IList cannot be modified. Une taille IList fixe ne permet pas l’ajout ou la suppression d’éléments, mais permet la modification des éléments existants.A fixed-size IList does not allow the addition or removal of elements, but it allows the modification of existing elements. Une taille IList variable permet l’ajout, la suppression et la modification d’éléments.A variable-size IList allows the addition, removal, and modification of elements.

Pour obtenir la version générique de cette interface, System.Collections.Generic.IList<T>consultez.For the generic version of this interface, see System.Collections.Generic.IList<T>.

Propriétés

Count

Obtient le nombre d'éléments contenus dans le ICollection.Gets the number of elements contained in the ICollection.

(Hérité de ICollection)
IsFixedSize

Obtient une valeur indiquant si IList est de taille fixe.Gets a value indicating whether the IList has a fixed size.

IsReadOnly

Obtient une valeur indiquant si IList est en lecture seule.Gets a value indicating whether the IList is read-only.

IsSynchronized

Obtient une valeur indiquant si l'accès à ICollection est synchronisé (thread-safe).Gets a value indicating whether access to the ICollection is synchronized (thread safe).

(Hérité de ICollection)
Item[Int32]

Obtient ou définit l'élément au niveau de l'index spécifié.Gets or sets the element at the specified index.

SyncRoot

Obtient un objet qui peut être utilisé pour synchroniser l'accès à ICollection.Gets an object that can be used to synchronize access to the ICollection.

(Hérité de ICollection)

Méthodes

Add(Object)

Ajoute un élément à IList.Adds an item to the IList.

Clear()

Supprime tous les éléments de IList.Removes all items from the IList.

Contains(Object)

Détermine si IList contient une valeur spécifique.Determines whether the IList contains a specific value.

CopyTo(Array, Int32)

Copie les éléments de ICollection dans Array, à partir d'un index particulier de Array.Copies the elements of the ICollection to an Array, starting at a particular Array index.

(Hérité de ICollection)
GetEnumerator()

Retourne un énumérateur qui itère au sein d’une collection.Returns an enumerator that iterates through a collection.

(Hérité de IEnumerable)
IndexOf(Object)

Détermine l'index d'un élément spécifique d'IList.Determines the index of a specific item in the IList.

Insert(Int32, Object)

Insère un élément dans IList à l'index spécifié.Inserts an item to the IList at the specified index.

Remove(Object)

Supprime la première occurrence d'un objet spécifique de IList.Removes the first occurrence of a specific object from the IList.

RemoveAt(Int32)

Supprime l'élément IList au niveau de l'index spécifié.Removes the IList item at the specified index.

Méthodes d’extension

Cast<TResult>(IEnumerable)

Effectue un cast des éléments d'un IEnumerable vers le type spécifié.Casts the elements of an IEnumerable to the specified type.

OfType<TResult>(IEnumerable)

Filtre les éléments d'un IEnumerable en fonction du type spécifié.Filters the elements of an IEnumerable based on a specified type.

AsParallel(IEnumerable)

Active la parallélisation d'une requête.Enables parallelization of a query.

AsQueryable(IEnumerable)

Convertit un IEnumerable en IQueryable.Converts an IEnumerable to an IQueryable.

S’applique à

Voir aussi