List<T>.Sort List<T>.Sort List<T>.Sort List<T>.Sort Method

Definizione

Ordina gli elementi o una parte degli elementi in List<T> usando l'implementazione specificata o IComparer<T> predefinita oppure un delegato Comparison<T> specificato per confrontare gli elementi dell'elenco.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.

Overload

Sort(Comparison<T>) Sort(Comparison<T>) Sort(Comparison<T>) Sort(Comparison<T>)

Ordina gli elementi nell'intera classe List<T> usando l'oggetto Comparison<T> specificato.Sorts the elements in the entire List<T> using the specified Comparison<T>.

Sort(Int32, Int32, IComparer<T>) Sort(Int32, Int32, IComparer<T>) Sort(Int32, Int32, IComparer<T>) Sort(Int32, Int32, IComparer<T>)

Ordina gli elementi di un intervallo di elementi di List<T> usando l'operatore di confronto specificato.Sorts the elements in a range of elements in List<T> using the specified comparer.

Sort() Sort() Sort() Sort()

Ordina gli elementi dell'intero oggetto List<T> utilizzando l'operatore di confronto predefinito.Sorts the elements in the entire List<T> using the default comparer.

Sort(IComparer<T>) Sort(IComparer<T>) Sort(IComparer<T>) Sort(IComparer<T>)

Ordina gli elementi dell'intero List<T> usando l'operatore di confronto specificato.Sorts the elements in the entire List<T> using the specified comparer.

Sort(Comparison<T>) Sort(Comparison<T>) Sort(Comparison<T>) Sort(Comparison<T>)

Ordina gli elementi nell'intera classe List<T> usando l'oggetto Comparison<T> specificato.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))

Parametri

comparison
Comparison<T> Comparison<T> Comparison<T> Comparison<T>

Oggetto Comparison<T> da usare quando si confrontano gli elementi.The Comparison<T> to use when comparing elements.

Eccezioni

L'implementazione di comparison ha causato un errore durante l'ordinamento.The implementation of comparison caused an error during the sort. Ad esempio, comparison potrebbe non restituire 0 quando si confronta un elemento con se stesso.For example, comparison might not return 0 when comparing an item with itself.

Esempi

Il codice seguente illustra il Sort e Sort overload del metodo su un semplice oggetto business.The following code demonstrates the Sort and Sort method overloads on a simple business object. Chiama il Sort metodo risulterà nell'uso dell'operatore di confronto predefinito per il tipo di parte e Sort metodo viene implementato usando un metodo anonimo.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

Nell'esempio seguente viene illustrato il Sort(Comparison<T>) overload del metodo.The following example demonstrates the Sort(Comparison<T>) method overload.

L'esempio definisce un metodo alternativo di confronto per le stringhe, denominato CompareDinosByLength.The example defines an alternative comparison method for strings, named CompareDinosByLength. Questo metodo funziona nel modo seguente: In primo luogo, i termini del confronto sono testate per null, e un riferimento null viene considerato minore rispetto a un diverso da 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. In secondo luogo, vengono confrontati con le lunghezze di stringa e la stringa più lunga viene considerata maggiore di.Second, the string lengths are compared, and the longer string is deemed to be greater. In terzo luogo, se le lunghezze sono uguali, viene utilizzato il confronto di stringa normali.Third, if the lengths are equal, ordinary string comparison is used.

Oggetto List<T> di stringhe viene creata e popolata con quattro stringhe, senza alcun ordine specifico.A List<T> of strings is created and populated with four strings, in no particular order. L'elenco include anche una stringa vuota e un riferimento null.The list also includes an empty string and a null reference. Viene visualizzato l'elenco, ordinato utilizzando un Comparison<T> delegato generico che rappresenta il CompareDinosByLength (metodo), quindi viene nuovamente visualizzato.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
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"

Commenti

Se comparison viene specificato, gli elementi del List<T> vengono ordinate usando il metodo rappresentato dal delegato.If comparison is provided, the elements of the List<T> are sorted using the method represented by the delegate.

Se comparison viene null, un ArgumentNullException viene generata un'eccezione.If comparison is null, an ArgumentNullException is thrown.

Questo metodo Usa Array.Sort, cui viene applicato l'ordinamento introspettivo come indicato di seguito:This method uses Array.Sort, which applies the introspective sort as follows:

  • Se la dimensione della partizione è inferiore a 16 elementi, viene utilizzato un algoritmo di ordinamento di inserimentoIf the partition size is fewer than 16 elements, it uses an insertion sort algorithm

  • Se il numero di partizioni supera log 2 n, dove n è l'intervallo della matrice di input, viene utilizzato un Heapsort algoritmo.If the number of partitions exceeds 2 log n, where n is the range of the input array, it uses a Heapsort algorithm.

  • In caso contrario, viene utilizzato un algoritmo Quicksort.Otherwise, it uses a Quicksort algorithm.

Questa implementazione esegue un ordinamento instabile; vale a dire, se due elementi sono uguali, l'ordine potrebbe non essere mantenuta.This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. Al contrario, un ordinamento stabile mantiene l'ordine degli elementi che sono uguali.In contrast, a stable sort preserves the order of elements that are equal.

In Media, questo metodo è un'operazione O (n registro n) operazione, in cui n è Count; nel caso peggiore è un'operazione O (n 2) operazione.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.

Vedi anche

Sort(Int32, Int32, IComparer<T>) Sort(Int32, Int32, IComparer<T>) Sort(Int32, Int32, IComparer<T>) Sort(Int32, Int32, IComparer<T>)

Ordina gli elementi di un intervallo di elementi di List<T> usando l'operatore di confronto specificato.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))

Parametri

index
Int32 Int32 Int32 Int32

Indice iniziale in base zero dell'intervallo da ordinare.The zero-based starting index of the range to sort.

count
Int32 Int32 Int32 Int32

Lunghezza dell'intervallo da ordinare.The length of the range to sort.

comparer
IComparer<T> IComparer<T> IComparer<T> IComparer<T>

Implementazione IComparer<T> da usare durante il confronto di elementi oppure null per usare la proprietà Default dell'operatore di confronto.The IComparer<T> implementation to use when comparing elements, or null to use the default comparer Default.

Eccezioni

index è minore di 0.index is less than 0.

In alternativa-or- count è minore di 0.count is less than 0.

index e count non specificano un intervallo valido in List<T>.index and count do not specify a valid range in the List<T>.

In alternativa-or- L'implementazione di comparer ha causato un errore durante l'ordinamento.The implementation of comparer caused an error during the sort. Ad esempio, comparer potrebbe non restituire 0 quando si confronta un elemento con se stesso.For example, comparer might not return 0 when comparing an item with itself.

comparer è null e l'operatore di confronto predefinito Default non riesce a trovare l'implementazione dell'interfaccia generica IComparable<T> o l'interfaccia IComparable per il tipo 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.

Esempi

Nell'esempio seguente viene illustrato il Sort(Int32, Int32, IComparer<T>) overload del metodo e BinarySearch(Int32, Int32, T, IComparer<T>) overload del metodo.The following example demonstrates the Sort(Int32, Int32, IComparer<T>) method overload and the BinarySearch(Int32, Int32, T, IComparer<T>) method overload.

L'esempio definisce un operatore alternativo per le stringhe denominata DinoCompare, che implementa il IComparer<string> (IComparer(Of String) in Visual Basic IComparer<String^> in Visual C++) dell'interfaccia generica.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. L'operatore di confronto funziona nel modo seguente: In primo luogo, i termini del confronto sono testate per null, e un riferimento null viene considerato minore rispetto a un diverso da 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. In secondo luogo, vengono confrontati con le lunghezze di stringa e la stringa più lunga viene considerata maggiore di.Second, the string lengths are compared, and the longer string is deemed to be greater. In terzo luogo, se le lunghezze sono uguali, viene utilizzato il confronto di stringa normali.Third, if the lengths are equal, ordinary string comparison is used.

Oggetto List<T> di stringhe viene creata e popolata con i nomi di cinque dinosaurs dinosauri e dinosaurs dinosauri tre.A List<T> of strings is created and populated with the names of five herbivorous dinosaurs and three carnivorous dinosaurs. All'interno di ognuno dei due gruppi, i nomi non sono in alcun ordine particolare.Within each of the two groups, the names are not in any particular sort order. Viene visualizzato l'elenco, l'intervallo di erbivori viene ordinato utilizzando l'operatore di confronto alternativo e viene nuovamente visualizzato l'elenco.The list is displayed, the range of herbivores is sorted using the alternate comparer, and the list is displayed again.

Il BinarySearch(Int32, Int32, T, IComparer<T>) overload del metodo viene quindi usato per cercare solo l'intervallo di erbivori "Brachiosaurus".The BinarySearch(Int32, Int32, T, IComparer<T>) method overload is then used to search only the range of herbivores for "Brachiosaurus". La stringa non viene trovata, il complemento bit per bit e (i ~ operatore in C# e Visual C++, Xor -1 in Visual Basic) del numero negativo restituito dal BinarySearch(Int32, Int32, T, IComparer<T>) metodo viene utilizzato come indice per l'inserimento della nuova stringa.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
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

Commenti

Se comparer viene specificato, gli elementi del List<T> vengono ordinate usando l'oggetto specificato IComparer<T> implementazione.If comparer is provided, the elements of the List<T> are sorted using the specified IComparer<T> implementation.

Se comparer viene null, l'operatore di confronto Comparer<T>.Default verifica se il tipo T implementa il IComparable<T> interfaccia generica e utilizza tale implementazione, se disponibile.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. In caso contrario, Comparer<T>.Default verifica se il tipo T implementa il IComparable interfaccia.If not, Comparer<T>.Default checks whether type T implements the IComparable interface. Se tipo T non implementa una delle due interfacce Comparer<T>.Default genera un InvalidOperationException.If type T does not implement either interface, Comparer<T>.Default throws an InvalidOperationException.

Questo metodo Usa Array.Sort, cui viene applicato l'ordinamento introspettivo come indicato di seguito:This method uses Array.Sort, which applies the introspective sort as follows:

  • Se la dimensione della partizione è inferiore a 16 elementi, viene utilizzato un algoritmo di ordinamento di inserimentoIf the partition size is fewer than 16 elements, it uses an insertion sort algorithm

  • Se il numero di partizioni supera log 2 n, dove n è l'intervallo della matrice di input, viene utilizzato un Heapsort algoritmo.If the number of partitions exceeds 2 log n, where n is the range of the input array, it uses a Heapsort algorithm.

  • In caso contrario, viene utilizzato un algoritmo Quicksort.Otherwise, it uses a Quicksort algorithm.

Questa implementazione esegue un ordinamento instabile; vale a dire, se due elementi sono uguali, l'ordine potrebbe non essere mantenuta.This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. Al contrario, un ordinamento stabile mantiene l'ordine degli elementi che sono uguali.In contrast, a stable sort preserves the order of elements that are equal.

In Media, questo metodo è un'operazione O (n registro n) operazione, in cui n è Count; nel caso peggiore è un'operazione O (n 2) operazione.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.

Vedi anche

Sort() Sort() Sort() Sort()

Ordina gli elementi dell'intero oggetto List<T> utilizzando l'operatore di confronto predefinito.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 ()

Eccezioni

Mediante la proprietà Default dell'operatore di confronto predefinito non è possibile rilevare un'implementazione dell'interfaccia generica IComparable<T> o dell'interfaccia IComparable per il tipo T.The default comparer Default cannot find an implementation of the IComparable<T> generic interface or the IComparable interface for type T.

Esempi

L'esempio seguente aggiunge alcuni nomi per un List<String> object, viene visualizzato l'elenco in ordine casuale, chiama il Sort (metodo) e quindi Visualizza l'elenco ordinato.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.

using System;
using System.Collections.Generic;

public class Example
{
   public static void Main()
   {
      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

Il codice seguente illustra il Sort() e Sort(Comparison<T>) overload del metodo su un semplice oggetto business.The following code demonstrates the Sort() and Sort(Comparison<T>) method overloads on a simple business object. Chiama il Sort() metodo risulterà nell'uso dell'operatore di confronto predefinito per il tipo di parte e Sort(Comparison<T>) metodo viene implementato usando un metodo anonimo.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

Nell'esempio seguente viene illustrato il Sort() overload del metodo e BinarySearch(T) overload del metodo.The following example demonstrates the Sort() method overload and the BinarySearch(T) method overload. Oggetto List<T> di stringhe viene creata e popolata con quattro stringhe, senza alcun ordine specifico.A List<T> of strings is created and populated with four strings, in no particular order. L'elenco è visualizzato, ordinato e visualizzato nuovamente.The list is displayed, sorted, and displayed again.

Il BinarySearch(T) overload del metodo viene quindi usato per eseguire la ricerca di due stringhe che non sono presenti nell'elenco, e il Insert metodo viene usato per inserirli.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. Il valore restituito del BinarySearch metodo è negativo in ogni caso, poiché le stringhe non sono presenti nell'elenco.The return value of the BinarySearch method is negative in each case, because the strings are not in the list. Prendendo il complemento bit per bit (di ~ operatore in C# e Visual C++, Xor -1 in Visual Basic) di questo numero negativo produce l'indice del primo elemento nell'elenco che in questa posizione è maggiore della stringa di ricerca e inserimento preserva l'ordinamento ordine.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 seconda stringa di ricerca è maggiore di qualsiasi elemento nell'elenco, in modo che la posizione di inserimento si trova alla fine dell'elenco.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
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

Commenti

Questo metodo Usa l'operatore di confronto Comparer<T>.Default per il tipo T per determinare l'ordine degli elementi dell'elenco.This method uses the default comparer Comparer<T>.Default for type T to determine the order of list elements. Il Comparer<T>.Default proprietà verifica se il tipo T implementa il IComparable<T> interfaccia generica e utilizza tale implementazione, se disponibile.The Comparer<T>.Default property checks whether type T implements the IComparable<T> generic interface and uses that implementation, if available. In caso contrario, Comparer<T>.Default verifica se il tipo T implementa il IComparable interfaccia.If not, Comparer<T>.Default checks whether type T implements the IComparable interface. Se tipo T non implementa una delle due interfacce Comparer<T>.Default genera un InvalidOperationException.If type T does not implement either interface, Comparer<T>.Default throws an InvalidOperationException.

Questo metodo Usa il Array.Sort metodo, che si applica l'ordinamento introspettivo come indicato di seguito:This method uses the Array.Sort method, which applies the introspective sort as follows:

  • Se la dimensione della partizione è inferiore a 16 elementi, viene utilizzato un algoritmo di ordinamento di inserimento.If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • Se il numero di partizioni supera log 2 n, dove n è l'intervallo della matrice di input, viene utilizzato un algoritmo Heapsort.If the number of partitions exceeds 2 log n, where n is the range of the input array, it uses a Heapsort algorithm.

  • In caso contrario, viene utilizzato un algoritmo Quicksort.Otherwise, it uses a Quicksort algorithm.

Questa implementazione esegue un ordinamento instabile; vale a dire, se due elementi sono uguali, l'ordine potrebbe non essere mantenuta.This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. Al contrario, un ordinamento stabile mantiene l'ordine degli elementi che sono uguali.In contrast, a stable sort preserves the order of elements that are equal.

In Media, questo metodo è un'operazione O (n registro n) operazione, in cui n è Count; nel caso peggiore è un'operazione O (n 2) operazione.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.

Vedi anche

Sort(IComparer<T>) Sort(IComparer<T>) Sort(IComparer<T>) Sort(IComparer<T>)

Ordina gli elementi dell'intero List<T> usando l'operatore di confronto specificato.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))

Parametri

comparer
IComparer<T> IComparer<T> IComparer<T> IComparer<T>

Implementazione IComparer<T> da usare durante il confronto di elementi oppure null per usare la proprietà Default dell'operatore di confronto.The IComparer<T> implementation to use when comparing elements, or null to use the default comparer Default.

Eccezioni

comparer è null e l'operatore di confronto predefinito Default non riesce a trovare l'implementazione dell'interfaccia generica IComparable<T> o l'interfaccia IComparable per il tipo 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'implementazione di comparer ha causato un errore durante l'ordinamento.The implementation of comparer caused an error during the sort. Ad esempio, comparer potrebbe non restituire 0 quando si confronta un elemento con se stesso.For example, comparer might not return 0 when comparing an item with itself.

Esempi

Nell'esempio seguente viene illustrato il Sort(IComparer<T>) overload del metodo e BinarySearch(T, IComparer<T>) overload del metodo.The following example demonstrates the Sort(IComparer<T>) method overload and the BinarySearch(T, IComparer<T>) method overload.

L'esempio definisce un operatore alternativo per le stringhe denominata DinoCompare, che implementa il IComparer<string> (IComparer(Of String) in Visual Basic IComparer<String^> in Visual C++) dell'interfaccia generica.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. L'operatore di confronto funziona nel modo seguente: In primo luogo, i termini del confronto sono testate per null, e un riferimento null viene considerato minore rispetto a un diverso da 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. In secondo luogo, vengono confrontati con le lunghezze di stringa e la stringa più lunga viene considerata maggiore di.Second, the string lengths are compared, and the longer string is deemed to be greater. In terzo luogo, se le lunghezze sono uguali, viene utilizzato il confronto di stringa normali.Third, if the lengths are equal, ordinary string comparison is used.

Oggetto List<T> di stringhe viene creata e popolata con quattro stringhe, senza alcun ordine specifico.A List<T> of strings is created and populated with four strings, in no particular order. L'elenco viene visualizzato, ordinato usando l'operatore di confronto alternativo e visualizzata nuovamente.The list is displayed, sorted using the alternate comparer, and displayed again.

Il BinarySearch(T, IComparer<T>) overload del metodo viene quindi usato per cercare più stringhe non in elenco, utilizzando l'operatore di confronto alternativo.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. Il Insert metodo viene utilizzato per inserire le stringhe.The Insert method is used to insert the strings. Questi due metodi si trovano nella funzione denominata SearchAndInsert, insieme al codice per utilizzare il complemento bit per bit (il ~ operatore in C# e Visual C++ Xor -1 in Visual Basic) del numero negativo restituito da BinarySearch(T, IComparer<T>) e usarlo come un indice per inserimento della nuova stringa.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
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

Commenti

Se comparer viene specificato, gli elementi del List<T> vengono ordinate usando l'oggetto specificato IComparer<T> implementazione.If comparer is provided, the elements of the List<T> are sorted using the specified IComparer<T> implementation.

Se comparer viene null, l'operatore di confronto Comparer<T>.Default verifica se il tipo T implementa il IComparable<T> interfaccia generica e utilizza tale implementazione, se disponibile.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. In caso contrario, Comparer<T>.Default verifica se il tipo T implementa il IComparable interfaccia.If not, Comparer<T>.Default checks whether type T implements the IComparable interface. Se tipo T non implementa una delle due interfacce Comparer<T>.Default genera un InvalidOperationException.If type T does not implement either interface, Comparer<T>.Default throws an InvalidOperationException.

Questo metodo Usa il Array.Sort metodo, che si applica l'ordinamento introspettivo come indicato di seguito:This method uses the Array.Sort method, which applies the introspective sort as follows:

  • Se la dimensione della partizione è inferiore a 16 elementi, viene utilizzato un algoritmo di ordinamento di inserimento.If the partition size is fewer than 16 elements, it uses an insertion sort algorithm.

  • Se il numero di partizioni supera log 2 n, dove n è l'intervallo della matrice di input, viene utilizzato un algoritmo Heapsort.If the number of partitions exceeds 2 log n, where n is the range of the input array, it uses a Heapsort algorithm.

  • In caso contrario, viene utilizzato un algoritmo Quicksort.Otherwise, it uses a Quicksort algorithm.

Questa implementazione esegue un ordinamento instabile; vale a dire, se due elementi sono uguali, l'ordine potrebbe non essere mantenuta.This implementation performs an unstable sort; that is, if two elements are equal, their order might not be preserved. Al contrario, un ordinamento stabile mantiene l'ordine degli elementi che sono uguali.In contrast, a stable sort preserves the order of elements that are equal.

In Media, questo metodo è un'operazione O (n registro n) operazione, in cui n è Count; nel caso peggiore è un'operazione O (n 2) operazione.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.

Vedi anche

Si applica a