List<T>.Sort Méthode

Définition

Trie les éléments ou une partie des éléments dans List<T> à l’aide de l’implémentation IComparer<T> spécifiée ou par défaut ou un délégué Comparison<T> fourni pour comparer les éléments de la liste.Sorts the elements or a portion of the elements in the List<T> using either the specified or default IComparer<T> implementation or a provided Comparison<T> delegate to compare list elements.

Surcharges

Sort(Comparison<T>)

Trie les éléments dans l'ensemble de List<T> à l'aide du Comparison<T> spécifié.Sorts the elements in the entire List<T> using the specified Comparison<T>.

Sort(Int32, Int32, IComparer<T>)

Trie les éléments dans une plage d'éléments de List<T> à l'aide du comparateur spécifié.Sorts the elements in a range of elements in List<T> using the specified comparer.

Sort()

Trie les éléments dans l'ensemble de List<T> à l'aide du comparateur par défaut.Sorts the elements in the entire List<T> using the default comparer.

Sort(IComparer<T>)

Trie les éléments dans l'ensemble de List<T> à l'aide du comparateur spécifié.Sorts the elements in the entire List<T> using the specified comparer.

Sort(Comparison<T>)

Trie les éléments dans l'ensemble de List<T> à l'aide du Comparison<T> spécifié.Sorts the elements in the entire List<T> using the specified Comparison<T>.

public:
 void Sort(Comparison<T> ^ comparison);
public void Sort (Comparison<T> comparison);
member this.Sort : Comparison<'T> -> unit
Public Sub Sort (comparison As Comparison(Of T))

Paramètres

comparison
Comparison<T>

Comparison<T> à utiliser pendant la comparaison d'éléments.The Comparison<T> to use when comparing elements.

Exceptions

comparison a la valeur null.comparison is null.

L’implémentation de comparison a provoqué une erreur pendant le tri.The implementation of comparison caused an error during the sort. Par exemple, comparison peut ne pas retourner 0 pendant la comparaison d’un élément à lui-même.For example, comparison might not return 0 when comparing an item with itself.

Exemples

Le code suivant illustre les surcharges de méthode Sort et Sort sur un objet métier simple.The following code demonstrates the Sort and Sort method overloads on a simple business object. L’appel de la méthode Sort entraîne l’utilisation du comparateur par défaut pour le type de composant, et la méthode Sort est implémentée à l’aide d’une méthode anonyme.Calling the Sort method results in the use of the default comparer for the Part type, and the Sort method is implemented using an anonymous method.

using System;
using System.Collections.Generic;
// Simple business object. A PartId is used to identify the type of part 
// but the part name can change. 
public class Part : IEquatable<Part> , IComparable<Part>
{
    public string PartName { get; set; }

    public int PartId { get; set; }

    public override string ToString()
    {
        return "ID: " + PartId + "   Name: " + PartName;
    }
    public override bool Equals(object obj)
    {
        if (obj == null) return false;
        Part objAsPart = obj as Part;
        if (objAsPart == null) return false;
        else return Equals(objAsPart);
    }
    public int SortByNameAscending(string name1, string name2)
    {
        
        return name1.CompareTo(name2);
    }

    // Default comparer for Part type.
    public int CompareTo(Part comparePart)
    {
          // A null value means that this object is greater.
        if (comparePart == null)
            return 1;
            
        else
            return this.PartId.CompareTo(comparePart.PartId);
    }
    public override int GetHashCode()
    {
        return PartId;
    }
    public bool Equals(Part other)
    {
        if (other == null) return false;
        return (this.PartId.Equals(other.PartId));
    }
    // Should also override == and != operators.

}
public class Example
{
    public static void Main()
    {
        // Create a list of parts.
        List<Part> parts = new List<Part>();

        // Add parts to the list.
        parts.Add(new Part() { PartName = "regular seat", PartId = 1434 });
        parts.Add(new Part() { PartName= "crank arm", PartId = 1234 });
        parts.Add(new Part() { PartName = "shift lever", PartId = 1634 }); ;
        // Name intentionally left null.
        parts.Add(new Part() {  PartId = 1334 });
        parts.Add(new Part() { PartName = "banana seat", PartId = 1444 });
        parts.Add(new Part() { PartName = "cassette", PartId = 1534 });
       

        // Write out the parts in the list. This will call the overridden 
        // ToString method in the Part class.
        Console.WriteLine("\nBefore sort:");
        foreach (Part aPart in parts)
        {
            Console.WriteLine(aPart);
        }


        // Call Sort on the list. This will use the 
        // default comparer, which is the Compare method 
        // implemented on Part.
        parts.Sort();


        Console.WriteLine("\nAfter sort by part number:");
        foreach (Part aPart in parts)
        {
            Console.WriteLine(aPart);
        }
       
        // This shows calling the Sort(Comparison(T) overload using 
        // an anonymous method for the Comparison delegate. 
        // This method treats null as the lesser of two values.
        parts.Sort(delegate(Part x, Part y)
        {
            if (x.PartName == null && y.PartName == null) return 0;
            else if (x.PartName == null) return -1;
            else if (y.PartName == null) return 1;
            else return x.PartName.CompareTo(y.PartName);
        });

        Console.WriteLine("\nAfter sort by name:");
        foreach (Part aPart in parts)
        {
            Console.WriteLine(aPart);
        }
       
        /*
       
            Before sort:
        ID: 1434   Name: regular seat
        ID: 1234   Name: crank arm
        ID: 1634   Name: shift lever
        ID: 1334   Name:
        ID: 1444   Name: banana seat
        ID: 1534   Name: cassette

        After sort by part number:
        ID: 1234   Name: crank arm
        ID: 1334   Name:
        ID: 1434   Name: regular seat
        ID: 1444   Name: banana seat
        ID: 1534   Name: cassette
        ID: 1634   Name: shift lever

        After sort by name:
        ID: 1334   Name:
        ID: 1444   Name: banana seat
        ID: 1534   Name: cassette
        ID: 1234   Name: crank arm
        ID: 1434   Name: regular seat
        ID: 1634   Name: shift lever

         */

    }
}
Imports System.Collections.Generic

' Simple business object. A PartId is used to identify the type of part 
' but the part name can change. 
Public Class Part
    Implements IEquatable(Of Part)
    Implements IComparable(Of Part)
    Public Property PartName() As String
        Get
            Return m_PartName
        End Get
        Set(value As String)
            m_PartName = Value
        End Set
    End Property
    Private m_PartName As String

    Public Property PartId() As Integer
        Get
            Return m_PartId
        End Get
        Set(value As Integer)
            m_PartId = Value
        End Set
    End Property
    Private m_PartId As Integer

    Public Overrides Function ToString() As String
        Return "ID: " & PartId & "   Name: " & PartName
    End Function

    Public Overrides Function Equals(obj As Object) As Boolean
        If obj Is Nothing Then
            Return False
        End If
        Dim objAsPart As Part = TryCast(obj, Part)
        If objAsPart Is Nothing Then
            Return False
        Else
            Return Equals(objAsPart)
        End If
    End Function

    Public Function SortByNameAscending(name1 As String, name2 As String) As Integer

        Return name1.CompareTo(name2)
    End Function

    ' Default comparer for Part.
    Public Function CompareTo(comparePart As Part) As Integer _
            Implements IComparable(Of ListSortVB.Part).CompareTo
        ' A null value means that this object is greater.
        If comparePart Is Nothing Then
            Return 1
        Else

            Return Me.PartId.CompareTo(comparePart.PartId)
        End If
    End Function
    Public Overrides Function GetHashCode() As Integer
        Return PartId
    End Function
    Public Overloads Function Equals(other As Part) As Boolean Implements IEquatable(Of ListSortVB.Part).Equals
        If other Is Nothing Then
            Return False
        End If
        Return (Me.PartId.Equals(other.PartId))
    End Function
    ' Should also override == and != operators.

End Class
Public Class Example
    Public Shared Sub Main()
        ' Create a list of parts.
        Dim parts As New List(Of Part)()

        ' Add parts to the list.
        parts.Add(New Part() With { _
             .PartName = "regular seat", _
             .PartId = 1434 _
        })
        parts.Add(New Part() With { _
             .PartName = "crank arm", _
             .PartId = 1234 _
        })
        parts.Add(New Part() With { _
             .PartName = "shift lever", _
             .PartId = 1634 _
        })


        ' Name intentionally left null.
        parts.Add(New Part() With { _
             .PartId = 1334 _
        })
        parts.Add(New Part() With { _
             .PartName = "banana seat", _
             .PartId = 1444 _
        })
        parts.Add(New Part() With { _
             .PartName = "cassette", _
             .PartId = 1534 _
        })


        ' Write out the parts in the list. This will call the overridden 
        ' ToString method in the Part class.
        Console.WriteLine(vbLf & "Before sort:")
        For Each aPart As Part In parts
            Console.WriteLine(aPart)
        Next


        ' Call Sort on the list. This will use the 
        ' default comparer, which is the Compare method 
        ' implemented on Part.
        parts.Sort()


        Console.WriteLine(vbLf & "After sort by part number:")
        For Each aPart As Part In parts
            Console.WriteLine(aPart)
        Next

        ' This shows calling the Sort(Comparison(T) overload using 
        ' an anonymous delegate method. 
        ' This method treats null as the lesser of two values.
        parts.Sort(Function(x As Part, y As Part)
                             If x.PartName Is Nothing AndAlso y.PartName Is Nothing Then
                                 Return 0
                             ElseIf x.PartName Is Nothing Then
                                 Return -1
                             ElseIf y.PartName Is Nothing Then
                                 Return 1
                             Else
                                 Return x.PartName.CompareTo(y.PartName)
                             End If
                         End Function)
        

        Console.WriteLine(vbLf & "After sort by name:")
        For Each aPart As Part In parts
            Console.WriteLine(aPart)
        Next

        '
        '        
        '            Before sort:
        '            ID: 1434   Name: regular seat
        '            ID: 1234   Name: crank arm
        '            ID: 1634   Name: shift lever
        '            ID: 1334   Name:
        '            ID: 1444   Name: banana seat
        '            ID: 1534   Name: cassette
        '
        '            After sort by part number:
        '            ID: 1234   Name: crank arm
        '            ID: 1334   Name:
        '            ID: 1434   Name: regular seat
        '            ID: 1444   Name: banana seat
        '            ID: 1534   Name: cassette
        '            ID: 1634   Name: shift lever
        '
        '            After sort by name:
        '            ID: 1334   Name:
        '            ID: 1444   Name: banana seat
        '            ID: 1534   Name: cassette
        '            ID: 1234   Name: crank arm
        '            ID: 1434   Name: regular seat
        '            ID: 1634   Name: shift lever

    End Sub
End Class

L’exemple suivant illustre la surcharge de la méthode Sort(Comparison<T>).The following example demonstrates the Sort(Comparison<T>) method overload.

L’exemple définit une autre méthode de comparaison pour les chaînes, nommée CompareDinosByLength.The example defines an alternative comparison method for strings, named CompareDinosByLength. Cette méthode fonctionne comme suit : Tout d’abord, les comparateurs sont testés pour null, et une référence null est traitée comme inférieure à une valeur non null.This method works as follows: First, the comparands are tested for null, and a null reference is treated as less than a non-null. Deuxièmement, les longueurs de chaîne sont comparées et la chaîne la plus longue est considérée comme supérieure.Second, the string lengths are compared, and the longer string is deemed to be greater. Troisièmement, si les longueurs sont égales, la comparaison de chaînes ordinaire est utilisée.Third, if the lengths are equal, ordinary string comparison is used.

Une List<T> de chaînes est créée et remplie avec quatre chaînes, dans aucun ordre particulier.A List<T> of strings is created and populated with four strings, in no particular order. La liste comprend également une chaîne vide et une référence null.The list also includes an empty string and a null reference. La liste s’affiche, triée à l’aide d’un délégué générique Comparison<T> représentant la méthode CompareDinosByLength, puis affichée à nouveau.The list is displayed, sorted using a Comparison<T> generic delegate representing the CompareDinosByLength method, and displayed again.

using namespace System;
using namespace System::Collections::Generic;

int CompareDinosByLength(String^ x, String^ y)
{
    if (x == nullptr)
    {
        if (y == nullptr)
        {
            // If x is null and y is null, they're
            // equal. 
            return 0;
        }
        else
        {
            // If x is null and y is not null, y
            // is greater. 
            return -1;
        }
    }
    else
    {
        // If x is not null...
        //
        if (y == nullptr)
            // ...and y is null, x is greater.
        {
            return 1;
        }
        else
        {
            // ...and y is not null, compare the 
            // lengths of the two strings.
            //
            int retval = x->Length.CompareTo(y->Length);

            if (retval != 0)
            {
                // If the strings are not of equal length,
                // the longer string is greater.
                //
                return retval;
            }
            else
            {
                // If the strings are of equal length,
                // sort them with ordinary string comparison.
                //
                return x->CompareTo(y);
            }
        }
    }
};

void Display(List<String^>^ list)
{
    Console::WriteLine();
    for each(String^ s in list)
    {
        if (s == nullptr)
            Console::WriteLine("(null)");
        else
            Console::WriteLine("\"{0}\"", s);
    }
};

void main()
{
    List<String^>^ dinosaurs = gcnew List<String^>();
    dinosaurs->Add("Pachycephalosaurus");
    dinosaurs->Add("Amargasaurus");
    dinosaurs->Add("");
    dinosaurs->Add(nullptr);
    dinosaurs->Add("Mamenchisaurus");
    dinosaurs->Add("Deinonychus");
    Display(dinosaurs);

    Console::WriteLine("\nSort with generic Comparison<String^> delegate:");
    dinosaurs->Sort(
        gcnew Comparison<String^>(CompareDinosByLength));
    Display(dinosaurs);

}

/* This code example produces the following output:

"Pachycephalosaurus"
"Amargasaurus"
""
(null)
"Mamenchisaurus"
"Deinonychus"

Sort with generic Comparison<String^> delegate:

(null)
""
"Deinonychus"
"Amargasaurus"
"Mamenchisaurus"
"Pachycephalosaurus"
 */
using System;
using System.Collections.Generic;

public class Example
{
    private static int CompareDinosByLength(string x, string y)
    {
        if (x == null)
        {
            if (y == null)
            {
                // If x is null and y is null, they're
                // equal. 
                return 0;
            }
            else
            {
                // If x is null and y is not null, y
                // is greater. 
                return -1;
            }
        }
        else
        {
            // If x is not null...
            //
            if (y == null)
                // ...and y is null, x is greater.
            {
                return 1;
            }
            else
            {
                // ...and y is not null, compare the 
                // lengths of the two strings.
                //
                int retval = x.Length.CompareTo(y.Length);

                if (retval != 0)
                {
                    // If the strings are not of equal length,
                    // the longer string is greater.
                    //
                    return retval;
                }
                else
                {
                    // If the strings are of equal length,
                    // sort them with ordinary string comparison.
                    //
                    return x.CompareTo(y);
                }
            }
        }
    }

    public static void Main()
    {
        List<string> dinosaurs = new List<string>();
        dinosaurs.Add("Pachycephalosaurus");
        dinosaurs.Add("Amargasaurus");
        dinosaurs.Add("");
        dinosaurs.Add(null);
        dinosaurs.Add("Mamenchisaurus");
        dinosaurs.Add("Deinonychus");
        Display(dinosaurs);

        Console.WriteLine("\nSort with generic Comparison<string> delegate:");
        dinosaurs.Sort(CompareDinosByLength);
        Display(dinosaurs);

    }

    private static void Display(List<string> list)
    {
        Console.WriteLine();
        foreach( string s in list )
        {
            if (s == null)
                Console.WriteLine("(null)");
            else
                Console.WriteLine("\"{0}\"", s);
        }
    }
}

/* This code example produces the following output:

"Pachycephalosaurus"
"Amargasaurus"
""
(null)
"Mamenchisaurus"
"Deinonychus"

Sort with generic Comparison<string> delegate:

(null)
""
"Deinonychus"
"Amargasaurus"
"Mamenchisaurus"
"Pachycephalosaurus"
 */
Imports System.Collections.Generic

Public Class Example

    Private Shared Function CompareDinosByLength( _
        ByVal x As String, ByVal y As String) As Integer

        If x Is Nothing Then
            If y Is Nothing Then 
                ' If x is Nothing and y is Nothing, they're
                ' equal. 
                Return 0
            Else
                ' If x is Nothing and y is not Nothing, y
                ' is greater. 
                Return -1
            End If
        Else
            ' If x is not Nothing...
            '
            If y Is Nothing Then
                ' ...and y is Nothing, x is greater.
                Return 1
            Else
                ' ...and y is not Nothing, compare the 
                ' lengths of the two strings.
                '
                Dim retval As Integer = _
                    x.Length.CompareTo(y.Length)

                If retval <> 0 Then 
                    ' If the strings are not of equal length,
                    ' the longer string is greater.
                    '
                    Return retval
                Else
                    ' If the strings are of equal length,
                    ' sort them with ordinary string comparison.
                    '
                    Return x.CompareTo(y)
                End If
            End If
        End If

    End Function

    Public Shared Sub Main()

        Dim dinosaurs As New List(Of String)
        dinosaurs.Add("Pachycephalosaurus")
        dinosaurs.Add("Amargasaurus")
        dinosaurs.Add("")
        dinosaurs.Add(Nothing)
        dinosaurs.Add("Mamenchisaurus")
        dinosaurs.Add("Deinonychus")
        Display(dinosaurs)

        Console.WriteLine(vbLf & "Sort with generic Comparison(Of String) delegate:")
        dinosaurs.Sort(AddressOf CompareDinosByLength)
        Display(dinosaurs)

    End Sub

    Private Shared Sub Display(ByVal lis As List(Of String))
        Console.WriteLine()
        For Each s As String In lis
            If s Is Nothing Then
                Console.WriteLine("(Nothing)")
            Else
                Console.WriteLine("""{0}""", s)
            End If
        Next
    End Sub
End Class

' This code example produces the following output:
'
'"Pachycephalosaurus"
'"Amargasaurus"
'""
'(Nothing)
'"Mamenchisaurus"
'"Deinonychus"
'
'Sort with generic Comparison(Of String) delegate:
'
'(Nothing)
'""
'"Deinonychus"
'"Amargasaurus"
'"Mamenchisaurus"
'"Pachycephalosaurus"

Remarques

Si comparison est fourni, les éléments de la List<T> sont triés à l’aide de la méthode représentée par le délégué.If comparison is provided, the elements of the List<T> are sorted using the method represented by the delegate.

Si comparison est null, une ArgumentNullException est levée.If comparison is null, an ArgumentNullException is thrown.

Cette méthode utilise Array.Sort, qui applique le tri inretrospect de la façon suivante :This method uses Array.Sort, which applies the introspective sort as follows:

  • Si la taille de la partition est inférieure ou égale à 16 éléments, elle utilise un algorithme de tri d’insertionIf the partition size is less than or equal to 16 elements, it uses an insertion sort algorithm

  • Si le nombre de partitions dépasse 2 log n, où n est la plage du tableau d’entrée, il utilise un algorithme HeapSort .If the number of partitions exceeds 2 log n, where n is the range of the input array, it uses a Heapsort algorithm.

  • Dans le cas contraire, il utilise un algorithme tri rapide.Otherwise, it uses a Quicksort algorithm.

Cette implémentation effectue un tri instable ; autrement dit, si deux éléments sont égaux, leur ordre peut ne pas être préservé.This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. En revanche, un tri stable préserve l’ordre des éléments qui sont égaux.In contrast, a stable sort preserves the order of elements that are equal.

En moyenne, cette méthode est une opération O (n log n), où n est Count; dans le pire des cas, il s’agit d’une opération O (n2).On average, this method is an O(n log n) operation, where n is Count; in the worst case it is an O(n2) operation.

Voir aussi

Sort(Int32, Int32, IComparer<T>)

Trie les éléments dans une plage d'éléments de List<T> à l'aide du comparateur spécifié.Sorts the elements in a range of elements in List<T> using the specified comparer.

public:
 void Sort(int index, int count, System::Collections::Generic::IComparer<T> ^ comparer);
public void Sort (int index, int count, System.Collections.Generic.IComparer<T> comparer);
member this.Sort : int * int * System.Collections.Generic.IComparer<'T> -> unit
Public Sub Sort (index As Integer, count As Integer, comparer As IComparer(Of T))

Paramètres

index
Int32

Index de début de base zéro de la plage à trier.The zero-based starting index of the range to sort.

count
Int32

Longueur de la plage à trier.The length of the range to sort.

comparer
IComparer<T>

Implémentation de IComparer<T> à utiliser pendant la comparaison d'éléments, ou null pour utiliser le comparateur par défaut Default.The IComparer<T> implementation to use when comparing elements, or null to use the default comparer Default.

Exceptions

index est inférieur à 0.index is less than 0.

- ou --or- count est inférieur à 0.count is less than 0.

index et count ne spécifient pas une plage valide dans le List<T>.index and count do not specify a valid range in the List<T>.

- ou --or- L’implémentation de comparer a provoqué une erreur pendant le tri.The implementation of comparer caused an error during the sort. Par exemple, comparer peut ne pas retourner 0 lors de la comparaison d’un élément à lui-même.For example, comparer might not return 0 when comparing an item with itself.

comparer a la valeur null, et le comparateur par défaut Default ne peut pas trouver d’implémentation de l’interface générique IComparable<T> ou de l’interface IComparable pour le type T.comparer is null, and the default comparer Default cannot find implementation of the IComparable<T> generic interface or the IComparable interface for type T.

Exemples

L’exemple suivant illustre la surcharge de méthode Sort(Int32, Int32, IComparer<T>) et la surcharge de méthode BinarySearch(Int32, Int32, T, IComparer<T>).The following example demonstrates the Sort(Int32, Int32, IComparer<T>) method overload and the BinarySearch(Int32, Int32, T, IComparer<T>) method overload.

L’exemple définit un autre comparateur pour les chaînes nommées DinoCompare, qui implémente le IComparer<string> (IComparer(Of String) dans Visual Basic, C++IComparer<String^> en visuel) interface générique.The example defines an alternative comparer for strings named DinoCompare, which implements the IComparer<string> (IComparer(Of String) in Visual Basic, IComparer<String^> in Visual C++) generic interface. Le comparateur fonctionne comme suit : Tout d’abord, les comparateurs sont testés pour null, et une référence null est traitée comme inférieure à une valeur non null.The comparer works as follows: First, the comparands are tested for null, and a null reference is treated as less than a non-null. Deuxièmement, les longueurs de chaîne sont comparées et la chaîne la plus longue est considérée comme supérieure.Second, the string lengths are compared, and the longer string is deemed to be greater. Troisièmement, si les longueurs sont égales, la comparaison de chaînes ordinaire est utilisée.Third, if the lengths are equal, ordinary string comparison is used.

Une List<T> de chaînes est créée et remplie avec les noms de cinq dinosaures herbivorous et trois dinosaures carnivores.A List<T> of strings is created and populated with the names of five herbivorous dinosaurs and three carnivorous dinosaurs. Dans chacun des deux groupes, les noms ne sont pas dans un ordre de tri particulier.Within each of the two groups, the names are not in any particular sort order. La liste s’affiche, la plage de herbivores est triée à l’aide de l’autre comparateur, et la liste s’affiche à nouveau.The list is displayed, the range of herbivores is sorted using the alternate comparer, and the list is displayed again.

La surcharge de méthode BinarySearch(Int32, Int32, T, IComparer<T>) est ensuite utilisée pour rechercher uniquement la plage de herbivores pour « Brachiosaurus ».The BinarySearch(Int32, Int32, T, IComparer<T>) method overload is then used to search only the range of herbivores for "Brachiosaurus". La chaîne est introuvable et le complément au niveau du bit (opérateur C# ~ dans C++et Visual,Xor-1 en Visual Basic) du nombre négatif retourné par la méthodeBinarySearch(Int32, Int32, T, IComparer<T>)est utilisé comme index pour l’insertion de la nouvelle chaîne.The string is not found, and the bitwise complement (the ~ operator in C# and Visual C++, Xor -1 in Visual Basic) of the negative number returned by the BinarySearch(Int32, Int32, T, IComparer<T>) method is used as an index for inserting the new string.

using namespace System;
using namespace System::Collections::Generic;

public ref class DinoComparer: IComparer<String^>
{
public:
    virtual int Compare(String^ x, String^ y)
    {
        if (x == nullptr)
        {
            if (y == nullptr)
            {
                // If x is null and y is null, they're
                // equal. 
                return 0;
            }
            else
            {
                // If x is null and y is not null, y
                // is greater. 
                return -1;
            }
        }
        else
        {
            // If x is not null...
            //
            if (y == nullptr)
                // ...and y is null, x is greater.
            {
                return 1;
            }
            else
            {
                // ...and y is not null, compare the 
                // lengths of the two strings.
                //
                int retval = x->Length.CompareTo(y->Length);

                if (retval != 0)
                {
                    // If the strings are not of equal length,
                    // the longer string is greater.
                    //
                    return retval;
                }
                else
                {
                    // If the strings are of equal length,
                    // sort them with ordinary string comparison.
                    //
                    return x->CompareTo(y);
                }
            }
        }
    }
};

void Display(List<String^>^ list)
{
    Console::WriteLine();
    for each(String^ s in list)
    {
        Console::WriteLine(s);
    }
};

void main()
{
    List<String^>^ dinosaurs = gcnew List<String^>();

    dinosaurs->Add("Pachycephalosaurus");
    dinosaurs->Add("Parasauralophus");
    dinosaurs->Add("Amargasaurus");
    dinosaurs->Add("Galimimus");
    dinosaurs->Add("Mamenchisaurus");
    dinosaurs->Add("Deinonychus");
    dinosaurs->Add("Oviraptor");
    dinosaurs->Add("Tyrannosaurus");

    int herbivores = 5;
    Display(dinosaurs);

    DinoComparer^ dc = gcnew DinoComparer();

    Console::WriteLine("\nSort a range with the alternate comparer:");
    dinosaurs->Sort(0, herbivores, dc);
    Display(dinosaurs);

    Console::WriteLine("\nBinarySearch a range and Insert \"{0}\":",
            "Brachiosaurus");

    int index = dinosaurs->BinarySearch(0, herbivores, "Brachiosaurus", dc);

    if (index < 0)
    {
        dinosaurs->Insert(~index, "Brachiosaurus");
        herbivores++;
    }

    Display(dinosaurs);
}

/* This code example produces the following output:

Pachycephalosaurus
Parasauralophus
Amargasaurus
Galimimus
Mamenchisaurus
Deinonychus
Oviraptor
Tyrannosaurus

Sort a range with the alternate comparer:

Galimimus
Amargasaurus
Mamenchisaurus
Parasauralophus
Pachycephalosaurus
Deinonychus
Oviraptor
Tyrannosaurus

BinarySearch a range and Insert "Brachiosaurus":

Galimimus
Amargasaurus
Brachiosaurus
Mamenchisaurus
Parasauralophus
Pachycephalosaurus
Deinonychus
Oviraptor
Tyrannosaurus
 */
using System;
using System.Collections.Generic;

public class DinoComparer: IComparer<string>
{
    public int Compare(string x, string y)
    {
        if (x == null)
        {
            if (y == null)
            {
                // If x is null and y is null, they're
                // equal. 
                return 0;
            }
            else
            {
                // If x is null and y is not null, y
                // is greater. 
                return -1;
            }
        }
        else
        {
            // If x is not null...
            //
            if (y == null)
                // ...and y is null, x is greater.
            {
                return 1;
            }
            else
            {
                // ...and y is not null, compare the 
                // lengths of the two strings.
                //
                int retval = x.Length.CompareTo(y.Length);

                if (retval != 0)
                {
                    // If the strings are not of equal length,
                    // the longer string is greater.
                    //
                    return retval;
                }
                else
                {
                    // If the strings are of equal length,
                    // sort them with ordinary string comparison.
                    //
                    return x.CompareTo(y);
                }
            }
        }
    }
}

public class Example
{
    public static void Main()
    {
        List<string> dinosaurs = new List<string>();

        dinosaurs.Add("Pachycephalosaurus");
        dinosaurs.Add("Parasauralophus");
        dinosaurs.Add("Amargasaurus");
        dinosaurs.Add("Galimimus");
        dinosaurs.Add("Mamenchisaurus");
        dinosaurs.Add("Deinonychus");
        dinosaurs.Add("Oviraptor");
        dinosaurs.Add("Tyrannosaurus");

        int herbivores = 5;
        Display(dinosaurs);

        DinoComparer dc = new DinoComparer();

        Console.WriteLine("\nSort a range with the alternate comparer:");
        dinosaurs.Sort(0, herbivores, dc);
        Display(dinosaurs);

        Console.WriteLine("\nBinarySearch a range and Insert \"{0}\":",
            "Brachiosaurus");

        int index = dinosaurs.BinarySearch(0, herbivores, "Brachiosaurus", dc);

        if (index < 0)
        {
            dinosaurs.Insert(~index, "Brachiosaurus");
            herbivores++;
        }

        Display(dinosaurs);
    }

    private static void Display(List<string> list)
    {
        Console.WriteLine();
        foreach( string s in list )
        {
            Console.WriteLine(s);
        }
    }
}

/* This code example produces the following output:

Pachycephalosaurus
Parasauralophus
Amargasaurus
Galimimus
Mamenchisaurus
Deinonychus
Oviraptor
Tyrannosaurus

Sort a range with the alternate comparer:

Galimimus
Amargasaurus
Mamenchisaurus
Parasauralophus
Pachycephalosaurus
Deinonychus
Oviraptor
Tyrannosaurus

BinarySearch a range and Insert "Brachiosaurus":

Galimimus
Amargasaurus
Brachiosaurus
Mamenchisaurus
Parasauralophus
Pachycephalosaurus
Deinonychus
Oviraptor
Tyrannosaurus
 */
Imports System.Collections.Generic

Public Class DinoComparer
    Implements IComparer(Of String)

    Public Function Compare(ByVal x As String, _
        ByVal y As String) As Integer _
        Implements IComparer(Of String).Compare

        If x Is Nothing Then
            If y Is Nothing Then 
                ' If x is Nothing and y is Nothing, they're
                ' equal. 
                Return 0
            Else
                ' If x is Nothing and y is not Nothing, y
                ' is greater. 
                Return -1
            End If
        Else
            ' If x is not Nothing...
            '
            If y Is Nothing Then
                ' ...and y is Nothing, x is greater.
                Return 1
            Else
                ' ...and y is not Nothing, compare the 
                ' lengths of the two strings.
                '
                Dim retval As Integer = _
                    x.Length.CompareTo(y.Length)

                If retval <> 0 Then 
                    ' If the strings are not of equal length,
                    ' the longer string is greater.
                    '
                    Return retval
                Else
                    ' If the strings are of equal length,
                    ' sort them with ordinary string comparison.
                    '
                    Return x.CompareTo(y)
                End If
            End If
        End If
    End Function
End Class

Public Class Example

    Public Shared Sub Main()

        Dim dinosaurs As New List(Of String)

        dinosaurs.Add("Pachycephalosaurus")
        dinosaurs.Add("Parasauralophus")
        dinosaurs.Add("Amargasaurus")
        dinosaurs.Add("Galimimus")
        dinosaurs.Add("Mamenchisaurus")
        dinosaurs.Add("Deinonychus")
        dinosaurs.Add("Oviraptor")
        dinosaurs.Add("Tyrannosaurus")

        Dim herbivores As Integer = 5
        Display(dinosaurs)

        Dim dc As New DinoComparer

        Console.WriteLine(vbLf & _
            "Sort a range with the alternate comparer:")
        dinosaurs.Sort(0, herbivores, dc)
        Display(dinosaurs)

        Console.WriteLine(vbLf & _
            "BinarySearch a range and Insert ""{0}"":", _
            "Brachiosaurus")

        Dim index As Integer = _
            dinosaurs.BinarySearch(0, herbivores, "Brachiosaurus", dc)

        If index < 0 Then
            index = index Xor -1
            dinosaurs.Insert(index, "Brachiosaurus")
            herbivores += 1
        End If

        Display(dinosaurs)

    End Sub

    Private Shared Sub Display(ByVal lis As List(Of String))
        Console.WriteLine()
        For Each s As String In lis
            Console.WriteLine(s)
        Next
    End Sub
End Class

' This code example produces the following output:
'
'Pachycephalosaurus
'Parasauralophus
'Amargasaurus
'Galimimus
'Mamenchisaurus
'Deinonychus
'Oviraptor
'Tyrannosaurus
'
'Sort a range with the alternate comparer:
'
'Galimimus
'Amargasaurus
'Mamenchisaurus
'Parasauralophus
'Pachycephalosaurus
'Deinonychus
'Oviraptor
'Tyrannosaurus
'
'BinarySearch a range and Insert "Brachiosaurus":
'
'Galimimus
'Amargasaurus
'Brachiosaurus
'Mamenchisaurus
'Parasauralophus
'Pachycephalosaurus
'Deinonychus
'Oviraptor
'Tyrannosaurus

Remarques

Si comparer est fourni, les éléments de la List<T> sont triés à l’aide de l’implémentation de IComparer<T> spécifiée.If comparer is provided, the elements of the List<T> are sorted using the specified IComparer<T> implementation.

Si comparer est null, le comparateur par défaut Comparer<T>.Default vérifie si le type T implémente l’interface générique IComparable<T> et utilise cette implémentation, si elle est disponible.If comparer is null, the default comparer Comparer<T>.Default checks whether type T implements the IComparable<T> generic interface and uses that implementation, if available. Si ce n’est pas le cas, Comparer<T>.Default vérifie si le type T implémente l’interface IComparable.If not, Comparer<T>.Default checks whether type T implements the IComparable interface. Si le type T n’implémente aucune interface, Comparer<T>.Default lève une InvalidOperationException.If type T does not implement either interface, Comparer<T>.Default throws an InvalidOperationException.

Cette méthode utilise Array.Sort, qui applique le tri inretrospect de la façon suivante :This method uses Array.Sort, which applies the introspective sort as follows:

  • Si la taille de la partition est inférieure ou égale à 16 éléments, elle utilise un algorithme de tri d’insertionIf the partition size is less than or equal to 16 elements, it uses an insertion sort algorithm

  • Si le nombre de partitions dépasse 2 log n, où n est la plage du tableau d’entrée, il utilise un algorithme HeapSort .If the number of partitions exceeds 2 log n, where n is the range of the input array, it uses a Heapsort algorithm.

  • Dans le cas contraire, il utilise un algorithme tri rapide.Otherwise, it uses a Quicksort algorithm.

Cette implémentation effectue un tri instable ; autrement dit, si deux éléments sont égaux, leur ordre peut ne pas être préservé.This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. En revanche, un tri stable préserve l’ordre des éléments qui sont égaux.In contrast, a stable sort preserves the order of elements that are equal.

En moyenne, cette méthode est une opération O (n log n), où n est Count; dans le pire des cas, il s’agit d’une opération O (n2).On average, this method is an O(n log n) operation, where n is Count; in the worst case it is an O(n2) operation.

Voir aussi

Sort()

Trie les éléments dans l'ensemble de List<T> à l'aide du comparateur par défaut.Sorts the elements in the entire List<T> using the default comparer.

public:
 void Sort();
public void Sort ();
member this.Sort : unit -> unit
Public Sub Sort ()

Exceptions

Le comparateur par défaut Default ne peut pas trouver une implémentation de l’interface générique IComparable<T> ou de l’interface IComparable pour le type T.The default comparer Default cannot find an implementation of the IComparable<T> generic interface or the IComparable interface for type T.

Exemples

L’exemple suivant ajoute des noms à un objet List<String>, affiche la liste dans un ordre non trié, appelle la méthode Sort, puis affiche la liste triée.The following example adds some names to a List<String> object, displays the list in unsorted order, calls the Sort method, and then displays the sorted list.

String[] names = { "Samuel", "Dakota", "Koani", "Saya", "Vanya", "Jody",
                   "Yiska", "Yuma", "Jody", "Nikita" };
var nameList = new List<String>();
nameList.AddRange(names);
Console.WriteLine("List in unsorted order: ");
foreach (var name in nameList)
   Console.Write("   {0}", name);

Console.WriteLine(Environment.NewLine);

nameList.Sort();
Console.WriteLine("List in sorted order: ");
foreach (var name in nameList)
   Console.Write("   {0}", name);

Console.WriteLine();

// The example displays the following output:
//    List in unsorted order:
//       Samuel   Dakota   Koani   Saya   Vanya   Jody   Yiska   Yuma   Jody   Nikita
//
//    List in sorted order:
//       Dakota   Jody   Jody   Koani   Nikita   Samuel   Saya   Vanya   Yiska   Yuma
Imports System.Collections.Generic

Module Example
   Public Sub Main()
      Dim names() As String = { "Samuel", "Dakota", "Koani", "Saya",
                                "Vanya", "Jody", "Yiska", "Yuma", 
                                "Jody", "Nikita" }
      Dim nameList As New List(Of String)()
      nameList.AddRange(names)
      Console.WriteLine("List in unsorted order: ")
      For Each name In nameList
         Console.Write("   {0}", name)
      Next
      Console.WriteLine(vbCrLf)

      nameList.Sort()
      Console.WriteLine("List in sorted order: ")
      For Each name In nameList
         Console.Write("   {0}", name)
      Next
      Console.WriteLine()
    End Sub
End Module
' The example displays the following output:
'    List in unsorted order:
'       Samuel   Dakota   Koani   Saya   Vanya   Jody   Yiska   Yuma   Jody   Nikita
'
'    List in sorted order:
'       Dakota   Jody   Jody   Koani   Nikita   Samuel   Saya   Vanya   Yiska   Yuma

Le code suivant illustre les surcharges de méthode Sort() et Sort(Comparison<T>) sur un objet métier simple.The following code demonstrates the Sort() and Sort(Comparison<T>) method overloads on a simple business object. L’appel de la méthode Sort() entraîne l’utilisation du comparateur par défaut pour le type de composant, et la méthode Sort(Comparison<T>) est implémentée à l’aide d’une méthode anonyme.Calling the Sort() method results in the use of the default comparer for the Part type, and the Sort(Comparison<T>) method is implemented by using an anonymous method.

using System;
using System.Collections.Generic;
// Simple business object. A PartId is used to identify the type of part 
// but the part name can change. 
public class Part : IEquatable<Part> , IComparable<Part>
{
    public string PartName { get; set; }

    public int PartId { get; set; }

    public override string ToString()
    {
        return "ID: " + PartId + "   Name: " + PartName;
    }
    public override bool Equals(object obj)
    {
        if (obj == null) return false;
        Part objAsPart = obj as Part;
        if (objAsPart == null) return false;
        else return Equals(objAsPart);
    }
    public int SortByNameAscending(string name1, string name2)
    {
        
        return name1.CompareTo(name2);
    }

    // Default comparer for Part type.
    public int CompareTo(Part comparePart)
    {
          // A null value means that this object is greater.
        if (comparePart == null)
            return 1;
            
        else
            return this.PartId.CompareTo(comparePart.PartId);
    }
    public override int GetHashCode()
    {
        return PartId;
    }
    public bool Equals(Part other)
    {
        if (other == null) return false;
        return (this.PartId.Equals(other.PartId));
    }
    // Should also override == and != operators.

}
public class Example
{
    public static void Main()
    {
        // Create a list of parts.
        List<Part> parts = new List<Part>();

        // Add parts to the list.
        parts.Add(new Part() { PartName = "regular seat", PartId = 1434 });
        parts.Add(new Part() { PartName= "crank arm", PartId = 1234 });
        parts.Add(new Part() { PartName = "shift lever", PartId = 1634 }); ;
        // Name intentionally left null.
        parts.Add(new Part() {  PartId = 1334 });
        parts.Add(new Part() { PartName = "banana seat", PartId = 1444 });
        parts.Add(new Part() { PartName = "cassette", PartId = 1534 });
       

        // Write out the parts in the list. This will call the overridden 
        // ToString method in the Part class.
        Console.WriteLine("\nBefore sort:");
        foreach (Part aPart in parts)
        {
            Console.WriteLine(aPart);
        }


        // Call Sort on the list. This will use the 
        // default comparer, which is the Compare method 
        // implemented on Part.
        parts.Sort();


        Console.WriteLine("\nAfter sort by part number:");
        foreach (Part aPart in parts)
        {
            Console.WriteLine(aPart);
        }
       
        // This shows calling the Sort(Comparison(T) overload using 
        // an anonymous method for the Comparison delegate. 
        // This method treats null as the lesser of two values.
        parts.Sort(delegate(Part x, Part y)
        {
            if (x.PartName == null && y.PartName == null) return 0;
            else if (x.PartName == null) return -1;
            else if (y.PartName == null) return 1;
            else return x.PartName.CompareTo(y.PartName);
        });

        Console.WriteLine("\nAfter sort by name:");
        foreach (Part aPart in parts)
        {
            Console.WriteLine(aPart);
        }
       
        /*
       
            Before sort:
        ID: 1434   Name: regular seat
        ID: 1234   Name: crank arm
        ID: 1634   Name: shift lever
        ID: 1334   Name:
        ID: 1444   Name: banana seat
        ID: 1534   Name: cassette

        After sort by part number:
        ID: 1234   Name: crank arm
        ID: 1334   Name:
        ID: 1434   Name: regular seat
        ID: 1444   Name: banana seat
        ID: 1534   Name: cassette
        ID: 1634   Name: shift lever

        After sort by name:
        ID: 1334   Name:
        ID: 1444   Name: banana seat
        ID: 1534   Name: cassette
        ID: 1234   Name: crank arm
        ID: 1434   Name: regular seat
        ID: 1634   Name: shift lever

         */

    }
}
Imports System.Collections.Generic

' Simple business object. A PartId is used to identify the type of part 
' but the part name can change. 
Public Class Part
    Implements IEquatable(Of Part)
    Implements IComparable(Of Part)
    Public Property PartName() As String
        Get
            Return m_PartName
        End Get
        Set(value As String)
            m_PartName = Value
        End Set
    End Property
    Private m_PartName As String

    Public Property PartId() As Integer
        Get
            Return m_PartId
        End Get
        Set(value As Integer)
            m_PartId = Value
        End Set
    End Property
    Private m_PartId As Integer

    Public Overrides Function ToString() As String
        Return "ID: " & PartId & "   Name: " & PartName
    End Function

    Public Overrides Function Equals(obj As Object) As Boolean
        If obj Is Nothing Then
            Return False
        End If
        Dim objAsPart As Part = TryCast(obj, Part)
        If objAsPart Is Nothing Then
            Return False
        Else
            Return Equals(objAsPart)
        End If
    End Function

    Public Function SortByNameAscending(name1 As String, name2 As String) As Integer

        Return name1.CompareTo(name2)
    End Function

    ' Default comparer for Part.
    Public Function CompareTo(comparePart As Part) As Integer _
            Implements IComparable(Of ListSortVB.Part).CompareTo
        ' A null value means that this object is greater.
        If comparePart Is Nothing Then
            Return 1
        Else

            Return Me.PartId.CompareTo(comparePart.PartId)
        End If
    End Function
    Public Overrides Function GetHashCode() As Integer
        Return PartId
    End Function
    Public Overloads Function Equals(other As Part) As Boolean Implements IEquatable(Of ListSortVB.Part).Equals
        If other Is Nothing Then
            Return False
        End If
        Return (Me.PartId.Equals(other.PartId))
    End Function
    ' Should also override == and != operators.

End Class
Public Class Example
    Public Shared Sub Main()
        ' Create a list of parts.
        Dim parts As New List(Of Part)()

        ' Add parts to the list.
        parts.Add(New Part() With { _
             .PartName = "regular seat", _
             .PartId = 1434 _
        })
        parts.Add(New Part() With { _
             .PartName = "crank arm", _
             .PartId = 1234 _
        })
        parts.Add(New Part() With { _
             .PartName = "shift lever", _
             .PartId = 1634 _
        })


        ' Name intentionally left null.
        parts.Add(New Part() With { _
             .PartId = 1334 _
        })
        parts.Add(New Part() With { _
             .PartName = "banana seat", _
             .PartId = 1444 _
        })
        parts.Add(New Part() With { _
             .PartName = "cassette", _
             .PartId = 1534 _
        })


        ' Write out the parts in the list. This will call the overridden 
        ' ToString method in the Part class.
        Console.WriteLine(vbLf & "Before sort:")
        For Each aPart As Part In parts
            Console.WriteLine(aPart)
        Next


        ' Call Sort on the list. This will use the 
        ' default comparer, which is the Compare method 
        ' implemented on Part.
        parts.Sort()


        Console.WriteLine(vbLf & "After sort by part number:")
        For Each aPart As Part In parts
            Console.WriteLine(aPart)
        Next

        ' This shows calling the Sort(Comparison(T) overload using 
        ' an anonymous delegate method. 
        ' This method treats null as the lesser of two values.
        parts.Sort(Function(x As Part, y As Part)
                             If x.PartName Is Nothing AndAlso y.PartName Is Nothing Then
                                 Return 0
                             ElseIf x.PartName Is Nothing Then
                                 Return -1
                             ElseIf y.PartName Is Nothing Then
                                 Return 1
                             Else
                                 Return x.PartName.CompareTo(y.PartName)
                             End If
                         End Function)
        

        Console.WriteLine(vbLf & "After sort by name:")
        For Each aPart As Part In parts
            Console.WriteLine(aPart)
        Next

        '
        '        
        '            Before sort:
        '            ID: 1434   Name: regular seat
        '            ID: 1234   Name: crank arm
        '            ID: 1634   Name: shift lever
        '            ID: 1334   Name:
        '            ID: 1444   Name: banana seat
        '            ID: 1534   Name: cassette
        '
        '            After sort by part number:
        '            ID: 1234   Name: crank arm
        '            ID: 1334   Name:
        '            ID: 1434   Name: regular seat
        '            ID: 1444   Name: banana seat
        '            ID: 1534   Name: cassette
        '            ID: 1634   Name: shift lever
        '
        '            After sort by name:
        '            ID: 1334   Name:
        '            ID: 1444   Name: banana seat
        '            ID: 1534   Name: cassette
        '            ID: 1234   Name: crank arm
        '            ID: 1434   Name: regular seat
        '            ID: 1634   Name: shift lever

    End Sub
End Class

L’exemple suivant illustre la surcharge de méthode Sort() et la surcharge de méthode BinarySearch(T).The following example demonstrates the Sort() method overload and the BinarySearch(T) method overload. Une List<T> de chaînes est créée et remplie avec quatre chaînes, dans aucun ordre particulier.A List<T> of strings is created and populated with four strings, in no particular order. La liste s’affiche, est triée et s’affiche à nouveau.The list is displayed, sorted, and displayed again.

La surcharge de méthode BinarySearch(T) est ensuite utilisée pour rechercher deux chaînes qui ne sont pas dans la liste, et la méthode Insert est utilisée pour les insérer.The BinarySearch(T) method overload is then used to search for two strings that are not in the list, and the Insert method is used to insert them. La valeur de retour de la méthode BinarySearch est négative dans chaque cas, car les chaînes ne sont pas dans la liste.The return value of the BinarySearch method is negative in each case, because the strings are not in the list. En prenant le complément de bits (l’opérateur C# ~ dans C++et Visual,Xor-1 en Visual Basic) de ce nombre négatif produit l’index du premier élément de la liste qui est plus grand que la chaîne de recherche, et l’insertion à cet emplacement conserve ordre de tri.Taking the bitwise complement (the ~ operator in C# and Visual C++, Xor -1 in Visual Basic) of this negative number produces the index of the first element in the list that is larger than the search string, and inserting at this location preserves the sort order. La deuxième chaîne de recherche est plus grande que n’importe quel élément de la liste, donc la position d’insertion se trouve à la fin de la liste.The second search string is larger than any element in the list, so the insertion position is at the end of the list.

using namespace System;
using namespace System::Collections::Generic;

void main()
{
    List<String^>^ dinosaurs = gcnew List<String^>();

    dinosaurs->Add("Pachycephalosaurus");
    dinosaurs->Add("Amargasaurus");
    dinosaurs->Add("Mamenchisaurus");
    dinosaurs->Add("Deinonychus");

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs)
    {
        Console::WriteLine(dinosaur);
    }

    Console::WriteLine("\nSort");
    dinosaurs->Sort();

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs)
    {
        Console::WriteLine(dinosaur);
    }

    Console::WriteLine("\nBinarySearch and Insert \"Coelophysis\":");
    int index = dinosaurs->BinarySearch("Coelophysis");
    if (index < 0)
    {
        dinosaurs->Insert(~index, "Coelophysis");
    }

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs)
    {
        Console::WriteLine(dinosaur);
    }

    Console::WriteLine("\nBinarySearch and Insert \"Tyrannosaurus\":");
    index = dinosaurs->BinarySearch("Tyrannosaurus");
    if (index < 0)
    {
        dinosaurs->Insert(~index, "Tyrannosaurus");
    }

    Console::WriteLine();
    for each(String^ dinosaur in dinosaurs)
    {
        Console::WriteLine(dinosaur);
    }
}

/* This code example produces the following output:

Pachycephalosaurus
Amargasaurus
Mamenchisaurus
Deinonychus

Sort

Amargasaurus
Deinonychus
Mamenchisaurus
Pachycephalosaurus

BinarySearch and Insert "Coelophysis":

Amargasaurus
Coelophysis
Deinonychus
Mamenchisaurus
Pachycephalosaurus

BinarySearch and Insert "Tyrannosaurus":

Amargasaurus
Coelophysis
Deinonychus
Mamenchisaurus
Pachycephalosaurus
Tyrannosaurus
 */
using System;
using System.Collections.Generic;

public class Example
{
    public static void Main()
    {
        List<string> dinosaurs = new List<string>();

        dinosaurs.Add("Pachycephalosaurus");
        dinosaurs.Add("Amargasaurus");
        dinosaurs.Add("Mamenchisaurus");
        dinosaurs.Add("Deinonychus");

        Console.WriteLine();
        foreach(string dinosaur in dinosaurs)
        {
            Console.WriteLine(dinosaur);
        }

        Console.WriteLine("\nSort");
        dinosaurs.Sort();

        Console.WriteLine();
        foreach(string dinosaur in dinosaurs)
        {
            Console.WriteLine(dinosaur);
        }

        Console.WriteLine("\nBinarySearch and Insert \"Coelophysis\":");
        int index = dinosaurs.BinarySearch("Coelophysis");
        if (index < 0)
        {
            dinosaurs.Insert(~index, "Coelophysis");
        }

        Console.WriteLine();
        foreach(string dinosaur in dinosaurs)
        {
            Console.WriteLine(dinosaur);
        }

        Console.WriteLine("\nBinarySearch and Insert \"Tyrannosaurus\":");
        index = dinosaurs.BinarySearch("Tyrannosaurus");
        if (index < 0)
        {
            dinosaurs.Insert(~index, "Tyrannosaurus");
        }

        Console.WriteLine();
        foreach(string dinosaur in dinosaurs)
        {
            Console.WriteLine(dinosaur);
        }
    }
}

/* This code example produces the following output:

Pachycephalosaurus
Amargasaurus
Mamenchisaurus
Deinonychus

Sort

Amargasaurus
Deinonychus
Mamenchisaurus
Pachycephalosaurus

BinarySearch and Insert "Coelophysis":

Amargasaurus
Coelophysis
Deinonychus
Mamenchisaurus
Pachycephalosaurus

BinarySearch and Insert "Tyrannosaurus":

Amargasaurus
Coelophysis
Deinonychus
Mamenchisaurus
Pachycephalosaurus
Tyrannosaurus
 */
Imports System.Collections.Generic

Public Class Example

    Public Shared Sub Main()

        Dim dinosaurs As New List(Of String)

        dinosaurs.Add("Pachycephalosaurus")
        dinosaurs.Add("Amargasaurus")
        dinosaurs.Add("Mamenchisaurus")
        dinosaurs.Add("Deinonychus")

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        Console.WriteLine(vbLf & "Sort")
        dinosaurs.Sort

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        Console.WriteLine(vbLf & _
            "BinarySearch and Insert ""Coelophysis"":")
        Dim index As Integer = dinosaurs.BinarySearch("Coelophysis")
        If index < 0 Then
            index = index Xor -1
            dinosaurs.Insert(index, "Coelophysis")
        End If

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

        Console.WriteLine(vbLf & _
            "BinarySearch and Insert ""Tyrannosaurus"":")
        index = dinosaurs.BinarySearch("Tyrannosaurus")
        If index < 0 Then
            index = index Xor -1
            dinosaurs.Insert(index, "Tyrannosaurus")
        End If

        Console.WriteLine()
        For Each dinosaur As String In dinosaurs
            Console.WriteLine(dinosaur)
        Next

    End Sub
End Class

' This code example produces the following output:
'
'Pachycephalosaurus
'Amargasaurus
'Mamenchisaurus
'Deinonychus
'
'Sort
'
'Amargasaurus
'Deinonychus
'Mamenchisaurus
'Pachycephalosaurus
'
'BinarySearch and Insert "Coelophysis":
'
'Amargasaurus
'Coelophysis
'Deinonychus
'Mamenchisaurus
'Pachycephalosaurus
'
'BinarySearch and Insert "Tyrannosaurus":
'
'Amargasaurus
'Coelophysis
'Deinonychus
'Mamenchisaurus
'Pachycephalosaurus
'Tyrannosaurus

Remarques

Cette méthode utilise le comparateur par défaut Comparer<T>.Default pour le type T pour déterminer l’ordre des éléments de liste.This method uses the default comparer Comparer<T>.Default for type T to determine the order of list elements. La propriété Comparer<T>.Default vérifie si le type T implémente l’interface générique IComparable<T> et utilise cette implémentation, si elle est disponible.The Comparer<T>.Default property checks whether type T implements the IComparable<T> generic interface and uses that implementation, if available. Si ce n’est pas le cas, Comparer<T>.Default vérifie si le type T implémente l’interface IComparable.If not, Comparer<T>.Default checks whether type T implements the IComparable interface. Si le type T n’implémente aucune interface, Comparer<T>.Default lève une InvalidOperationException.If type T does not implement either interface, Comparer<T>.Default throws an InvalidOperationException.

Cette méthode utilise la méthode Array.Sort, qui applique le tri inretrospect comme suit :This method uses the Array.Sort method, which applies the introspective sort as follows:

  • Si la taille de la partition est inférieure ou égale à 16 éléments, elle utilise un algorithme de tri d’insertion.If the partition size is less than or equal to 16 elements, it uses an insertion sort algorithm.

  • Si le nombre de partitions dépasse 2 log n, où n est la plage du tableau d’entrée, il utilise un algorithme HeapSort.If the number of partitions exceeds 2 log n, where n is the range of the input array, it uses a Heapsort algorithm.

  • Dans le cas contraire, il utilise un algorithme tri rapide.Otherwise, it uses a Quicksort algorithm.

Cette implémentation effectue un tri instable ; autrement dit, si deux éléments sont égaux, leur ordre peut ne pas être préservé.This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. En revanche, un tri stable préserve l’ordre des éléments qui sont égaux.In contrast, a stable sort preserves the order of elements that are equal.

En moyenne, cette méthode est une opération O (n log n), où n est Count; dans le pire des cas, il s’agit d’une opération O (n2).On average, this method is an O(n log n) operation, where n is Count; in the worst case it is an O(n2) operation.

Voir aussi

Sort(IComparer<T>)

Trie les éléments dans l'ensemble de List<T> à l'aide du comparateur spécifié.Sorts the elements in the entire List<T> using the specified comparer.

public:
 void Sort(System::Collections::Generic::IComparer<T> ^ comparer);
public void Sort (System.Collections.Generic.IComparer<T> comparer);
member this.Sort : System.Collections.Generic.IComparer<'T> -> unit
Public Sub Sort (comparer As IComparer(Of T))

Paramètres

comparer
IComparer<T>

Implémentation de IComparer<T> à utiliser pendant la comparaison d'éléments, ou null pour utiliser le comparateur par défaut Default.The IComparer<T> implementation to use when comparing elements, or null to use the default comparer Default.

Exceptions

comparer a la valeur null, et le comparateur par défaut Default ne peut pas trouver d’implémentation de l’interface générique IComparable<T> ou de l’interface IComparable pour le type T.comparer is null, and the default comparer Default cannot find implementation of the IComparable<T> generic interface or the IComparable interface for type T.

L’implémentation de comparer a provoqué une erreur pendant le tri.The implementation of comparer caused an error during the sort. Par exemple, comparer peut ne pas retourner 0 pendant la comparaison d’un élément à lui-même.For example, comparer might not return 0 when comparing an item with itself.

Exemples

L’exemple suivant illustre la surcharge de méthode Sort(IComparer<T>) et la surcharge de méthode BinarySearch(T, IComparer<T>).The following example demonstrates the Sort(IComparer<T>) method overload and the BinarySearch(T, IComparer<T>) method overload.

L’exemple définit un autre comparateur pour les chaînes nommées DinoCompare, qui implémente le IComparer<string> (IComparer(Of String) dans Visual Basic, C++IComparer<String^> en visuel) interface générique.The example defines an alternative comparer for strings named DinoCompare, which implements the IComparer<string> (IComparer(Of String) in Visual Basic, IComparer<String^> in Visual C++) generic interface. Le comparateur fonctionne comme suit : Tout d’abord, les comparateurs sont testés pour null, et une référence null est traitée comme inférieure à une valeur non null.The comparer works as follows: First, the comparands are tested for null, and a null reference is treated as less than a non-null. Deuxièmement, les longueurs de chaîne sont comparées et la chaîne la plus longue est considérée comme supérieure.Second, the string lengths are compared, and the longer string is deemed to be greater. Troisièmement, si les longueurs sont égales, la comparaison de chaînes ordinaire est utilisée.Third, if the lengths are equal, ordinary string comparison is used.

Une List<T> de chaînes est créée et remplie avec quatre chaînes, dans aucun ordre particulier.A List<T> of strings is created and populated with four strings, in no particular order. La liste est affichée, triée à l’aide de l’autre comparateur et affichée à nouveau.The list is displayed, sorted using the alternate comparer, and displayed again.

La surcharge de méthode BinarySearch(T, IComparer<T>) est ensuite utilisée pour rechercher plusieurs chaînes qui ne sont pas dans la liste, en utilisant le comparateur de remplacement.The BinarySearch(T, IComparer<T>) method overload is then used to search for several strings that are not in the list, employing the alternate comparer. La méthode Insert est utilisée pour insérer les chaînes.The Insert method is used to insert the strings. Ces deux méthodes se trouvent dans la fonction nommée SearchAndInsert, ainsi que le code pour prendre le complément de bits (l’opérateur C# ~ dans C++et Visual,Xor-1 dans Visual Basic) du nombre négatif retourné parBinarySearch(T, IComparer<T>)et l’utiliser comme index pour l’instruction INSERT GN la nouvelle chaîne.These two methods are located in the function named SearchAndInsert, along with code to take the bitwise complement (the ~ operator in C# and Visual C++, Xor -1 in Visual Basic) of the negative number returned by BinarySearch(T, IComparer<T>) and use it as an index for inserting the new string.

using namespace System;
using namespace System::Collections::Generic;

public ref class DinoComparer: IComparer<String^>
{
public:
    virtual int Compare(String^ x, String^ y)
    {
        if (x == nullptr)
        {
            if (y == nullptr)
            {
                // If x is null and y is null, they're
                // equal. 
                return 0;
            }
            else
            {
                // If x is null and y is not null, y
                // is greater. 
                return -1;
            }
        }
        else
        {
            // If x is not null...
            //
            if (y == nullptr)
                // ...and y is null, x is greater.
            {
                return 1;
            }
            else
            {
                // ...and y is not null, compare the 
                // lengths of the two strings.
                //
                int retval = x->Length.CompareTo(y->Length);

                if (retval != 0)
                {
                    // If the strings are not of equal length,
                    // the longer string is greater.
                    //
                    return retval;
                }
                else
                {
                    // If the strings are of equal length,
                    // sort them with ordinary string comparison.
                    //
                    return x->CompareTo(y);
                }
            }
        }
    }
};

void SearchAndInsert(List<String^>^ list, String^ insert, 
    DinoComparer^ dc)
{
    Console::WriteLine("\nBinarySearch and Insert \"{0}\":", insert);

    int index = list->BinarySearch(insert, dc);

    if (index < 0)
    {
        list->Insert(~index, insert);
    }
};

void Display(List<String^>^ list)
{
    Console::WriteLine();
    for each(String^ s in list)
    {
        Console::WriteLine(s);
    }
};

void main()
{
    List<String^>^ dinosaurs = gcnew List<String^>();
    dinosaurs->Add("Pachycephalosaurus");
    dinosaurs->Add("Amargasaurus");
    dinosaurs->Add("Mamenchisaurus");
    dinosaurs->Add("Deinonychus");
    Display(dinosaurs);

    DinoComparer^ dc = gcnew DinoComparer();

    Console::WriteLine("\nSort with alternate comparer:");
    dinosaurs->Sort(dc);
    Display(dinosaurs);

    SearchAndInsert(dinosaurs, "Coelophysis", dc);
    Display(dinosaurs);

    SearchAndInsert(dinosaurs, "Oviraptor", dc);
    Display(dinosaurs);

    SearchAndInsert(dinosaurs, "Tyrannosaur", dc);
    Display(dinosaurs);

    SearchAndInsert(dinosaurs, nullptr, dc);
    Display(dinosaurs);
}

/* This code example produces the following output:

Pachycephalosaurus
Amargasaurus
Mamenchisaurus
Deinonychus

Sort with alternate comparer:

Deinonychus
Amargasaurus
Mamenchisaurus
Pachycephalosaurus

BinarySearch and Insert "Coelophysis":

Coelophysis
Deinonychus
Amargasaurus
Mamenchisaurus
Pachycephalosaurus

BinarySearch and Insert "Oviraptor":

Oviraptor
Coelophysis
Deinonychus
Amargasaurus
Mamenchisaurus
Pachycephalosaurus

BinarySearch and Insert "Tyrannosaur":

Oviraptor
Coelophysis
Deinonychus
Tyrannosaur
Amargasaurus
Mamenchisaurus
Pachycephalosaurus

BinarySearch and Insert "":


Oviraptor
Coelophysis
Deinonychus
Tyrannosaur
Amargasaurus
Mamenchisaurus
Pachycephalosaurus
 */
using System;
using System.Collections.Generic;

public class DinoComparer: IComparer<string>
{
    public int Compare(string x, string y)
    {
        if (x == null)
        {
            if (y == null)
            {
                // If x is null and y is null, they're
                // equal. 
                return 0;
            }
            else
            {
                // If x is null and y is not null, y
                // is greater. 
                return -1;
            }
        }
        else
        {
            // If x is not null...
            //
            if (y == null)
                // ...and y is null, x is greater.
            {
                return 1;
            }
            else
            {
                // ...and y is not null, compare the 
                // lengths of the two strings.
                //
                int retval = x.Length.CompareTo(y.Length);

                if (retval != 0)
                {
                    // If the strings are not of equal length,
                    // the longer string is greater.
                    //
                    return retval;
                }
                else
                {
                    // If the strings are of equal length,
                    // sort them with ordinary string comparison.
                    //
                    return x.CompareTo(y);
                }
            }
        }
    }
}

public class Example
{
    public static void Main()
    {
        List<string> dinosaurs = new List<string>();
        dinosaurs.Add("Pachycephalosaurus");
        dinosaurs.Add("Amargasaurus");
        dinosaurs.Add("Mamenchisaurus");
        dinosaurs.Add("Deinonychus");
        Display(dinosaurs);

        DinoComparer dc = new DinoComparer();

        Console.WriteLine("\nSort with alternate comparer:");
        dinosaurs.Sort(dc);
        Display(dinosaurs);

        SearchAndInsert(dinosaurs, "Coelophysis", dc);
        Display(dinosaurs);

        SearchAndInsert(dinosaurs, "Oviraptor", dc);
        Display(dinosaurs);

        SearchAndInsert(dinosaurs, "Tyrannosaur", dc);
        Display(dinosaurs);

        SearchAndInsert(dinosaurs, null, dc);
        Display(dinosaurs);
    }

    private static void SearchAndInsert(List<string> list, 
        string insert, DinoComparer dc)
    {
        Console.WriteLine("\nBinarySearch and Insert \"{0}\":", insert);

        int index = list.BinarySearch(insert, dc);

        if (index < 0)
        {
            list.Insert(~index, insert);
        }
    }

    private static void Display(List<string> list)
    {
        Console.WriteLine();
        foreach( string s in list )
        {
            Console.WriteLine(s);
        }
    }
}

/* This code example produces the following output:

Pachycephalosaurus
Amargasaurus
Mamenchisaurus
Deinonychus

Sort with alternate comparer:

Deinonychus
Amargasaurus
Mamenchisaurus
Pachycephalosaurus

BinarySearch and Insert "Coelophysis":

Coelophysis
Deinonychus
Amargasaurus
Mamenchisaurus
Pachycephalosaurus

BinarySearch and Insert "Oviraptor":

Oviraptor
Coelophysis
Deinonychus
Amargasaurus
Mamenchisaurus
Pachycephalosaurus

BinarySearch and Insert "Tyrannosaur":

Oviraptor
Coelophysis
Deinonychus
Tyrannosaur
Amargasaurus
Mamenchisaurus
Pachycephalosaurus

BinarySearch and Insert "":


Oviraptor
Coelophysis
Deinonychus
Tyrannosaur
Amargasaurus
Mamenchisaurus
Pachycephalosaurus
 */
Imports System.Collections.Generic

Public Class DinoComparer
    Implements IComparer(Of String)

    Public Function Compare(ByVal x As String, _
        ByVal y As String) As Integer _
        Implements IComparer(Of String).Compare

        If x Is Nothing Then
            If y Is Nothing Then 
                ' If x is Nothing and y is Nothing, they're
                ' equal. 
                Return 0
            Else
                ' If x is Nothing and y is not Nothing, y
                ' is greater. 
                Return -1
            End If
        Else
            ' If x is not Nothing...
            '
            If y Is Nothing Then
                ' ...and y is Nothing, x is greater.
                Return 1
            Else
                ' ...and y is not Nothing, compare the 
                ' lengths of the two strings.
                '
                Dim retval As Integer = _
                    x.Length.CompareTo(y.Length)

                If retval <> 0 Then 
                    ' If the strings are not of equal length,
                    ' the longer string is greater.
                    '
                    Return retval
                Else
                    ' If the strings are of equal length,
                    ' sort them with ordinary string comparison.
                    '
                    Return x.CompareTo(y)
                End If
            End If
        End If
    End Function
End Class

Public Class Example

    Public Shared Sub Main()

        Dim dinosaurs As New List(Of String)
        dinosaurs.Add("Pachycephalosaurus")
        dinosaurs.Add("Amargasaurus")
        dinosaurs.Add("Mamenchisaurus")
        dinosaurs.Add("Deinonychus")
        Display(dinosaurs)

        Dim dc As New DinoComparer

        Console.WriteLine(vbLf & "Sort with alternate comparer:")
        dinosaurs.Sort(dc)
        Display(dinosaurs)

        SearchAndInsert(dinosaurs, "Coelophysis", dc)
        Display(dinosaurs)

        SearchAndInsert(dinosaurs, "Oviraptor", dc)
        Display(dinosaurs)

        SearchAndInsert(dinosaurs, "Tyrannosaur", dc)
        Display(dinosaurs)

        SearchAndInsert(dinosaurs, Nothing, dc)
        Display(dinosaurs)
    End Sub

    Private Shared Sub SearchAndInsert( _
        ByVal lis As List(Of String), _
        ByVal insert As String, ByVal dc As DinoComparer)

        Console.WriteLine(vbLf & _
            "BinarySearch and Insert ""{0}"":", insert)

        Dim index As Integer = lis.BinarySearch(insert, dc)

        If index < 0 Then
            index = index Xor -1
            lis.Insert(index, insert)
        End If
    End Sub

    Private Shared Sub Display(ByVal lis As List(Of String))
        Console.WriteLine()
        For Each s As String In lis
            Console.WriteLine(s)
        Next
    End Sub
End Class

' This code example produces the following output:
'
'Pachycephalosaurus
'Amargasaurus
'Mamenchisaurus
'Deinonychus
'
'Sort with alternate comparer:
'
'Deinonychus
'Amargasaurus
'Mamenchisaurus
'Pachycephalosaurus
'
'BinarySearch and Insert "Coelophysis":
'
'Coelophysis
'Deinonychus
'Amargasaurus
'Mamenchisaurus
'Pachycephalosaurus
'
'BinarySearch and Insert "Oviraptor":
'
'Oviraptor
'Coelophysis
'Deinonychus
'Amargasaurus
'Mamenchisaurus
'Pachycephalosaurus
'
'BinarySearch and Insert "Tyrannosaur":
'
'Oviraptor
'Coelophysis
'Deinonychus
'Tyrannosaur
'Amargasaurus
'Mamenchisaurus
'Pachycephalosaurus
'
'BinarySearch and Insert "":
'
'
'Oviraptor
'Coelophysis
'Deinonychus
'Tyrannosaur
'Amargasaurus
'Mamenchisaurus
'Pachycephalosaurus

Remarques

Si comparer est fourni, les éléments de la List<T> sont triés à l’aide de l’implémentation de IComparer<T> spécifiée.If comparer is provided, the elements of the List<T> are sorted using the specified IComparer<T> implementation.

Si comparer est null, le comparateur par défaut Comparer<T>.Default vérifie si le type T implémente l’interface générique IComparable<T> et utilise cette implémentation, si elle est disponible.If comparer is null, the default comparer Comparer<T>.Default checks whether type T implements the IComparable<T> generic interface and uses that implementation, if available. Si ce n’est pas le cas, Comparer<T>.Default vérifie si le type T implémente l’interface IComparable.If not, Comparer<T>.Default checks whether type T implements the IComparable interface. Si le type T n’implémente aucune interface, Comparer<T>.Default lève une InvalidOperationException.If type T does not implement either interface, Comparer<T>.Default throws an InvalidOperationException.

Cette méthode utilise la méthode Array.Sort, qui applique le tri inretrospect comme suit :This method uses the Array.Sort method, which applies the introspective sort as follows:

  • Si la taille de la partition est inférieure ou égale à 16 éléments, elle utilise un algorithme de tri d’insertion.If the partition size is less than or equal to 16 elements, it uses an insertion sort algorithm.

  • Si le nombre de partitions dépasse 2 log n, où n est la plage du tableau d’entrée, il utilise un algorithme HeapSort.If the number of partitions exceeds 2 log n, where n is the range of the input array, it uses a Heapsort algorithm.

  • Dans le cas contraire, il utilise un algorithme tri rapide.Otherwise, it uses a Quicksort algorithm.

Cette implémentation effectue un tri instable ; autrement dit, si deux éléments sont égaux, leur ordre peut ne pas être préservé.This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. En revanche, un tri stable préserve l’ordre des éléments qui sont égaux.In contrast, a stable sort preserves the order of elements that are equal.

En moyenne, cette méthode est une opération O (n log n), où n est Count; dans le pire des cas, il s’agit d’une opération O (n2).On average, this method is an O(n log n) operation, where n is Count; in the worst case it is an O(n2) operation.

Voir aussi

S’applique à