SortedList<TKey,TValue> Classe

Definizione

generic <typename TKey, typename TValue>
public ref class SortedList : System::Collections::Generic::ICollection<System::Collections::Generic::KeyValuePair<TKey, TValue>>, System::Collections::Generic::IDictionary<TKey, TValue>, System::Collections::Generic::IEnumerable<System::Collections::Generic::KeyValuePair<TKey, TValue>>, System::Collections::Generic::IReadOnlyCollection<System::Collections::Generic::KeyValuePair<TKey, TValue>>, System::Collections::Generic::IReadOnlyDictionary<TKey, TValue>, System::Collections::IDictionary

generic <typename TKey, typename TValue>
public ref class SortedList : System::Collections::Generic::ICollection<System::Collections::Generic::KeyValuePair<TKey, TValue>>, System::Collections::Generic::IDictionary<TKey, TValue>, System::Collections::Generic::IEnumerable<System::Collections::Generic::KeyValuePair<TKey, TValue>>, System::Collections::IDictionary

public class SortedList<TKey,TValue> : System.Collections.Generic.ICollection<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IDictionary<TKey,TValue>, System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IReadOnlyCollection<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IReadOnlyDictionary<TKey,TValue>, System.Collections.IDictionary

[System.Runtime.InteropServices.ComVisible(false)]
[System.Serializable]
public class SortedList<TKey,TValue> : System.Collections.Generic.ICollection<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IDictionary<TKey,TValue>, System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.IDictionary

[System.Runtime.InteropServices.ComVisible(false)]
[System.Serializable]
public class SortedList<TKey,TValue> : System.Collections.Generic.ICollection<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IDictionary<TKey,TValue>, System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IReadOnlyCollection<System.Collections.Generic.KeyValuePair<TKey,TValue>>, System.Collections.Generic.IReadOnlyDictionary<TKey,TValue>, System.Collections.IDictionary

type SortedList<'Key, 'Value> = class
    interface ICollection<KeyValuePair<'Key, 'Value>>
    interface seq<KeyValuePair<'Key, 'Value>>
    interface IEnumerable
    interface IDictionary<'Key, 'Value>
    interface IReadOnlyCollection<KeyValuePair<'Key, 'Value>>
    interface IReadOnlyDictionary<'Key, 'Value>
    interface ICollection
    interface IDictionary

[<System.Runtime.InteropServices.ComVisible(false)>]
[<System.Serializable>]
type SortedList<'Key, 'Value> = class
    interface IDictionary<'Key, 'Value>
    interface ICollection<KeyValuePair<'Key, 'Value>>
    interface seq<KeyValuePair<'Key, 'Value>>
    interface IDictionary
    interface ICollection
    interface IEnumerable

[<System.Runtime.InteropServices.ComVisible(false)>]
[<System.Serializable>]
type SortedList<'Key, 'Value> = class
    interface IDictionary<'Key, 'Value>
    interface ICollection<KeyValuePair<'Key, 'Value>>
    interface seq<KeyValuePair<'Key, 'Value>>
    interface IEnumerable
    interface IDictionary
    interface ICollection
    interface IReadOnlyDictionary<'Key, 'Value>
    interface IReadOnlyCollection<KeyValuePair<'Key, 'Value>>

Public Class SortedList(Of TKey, TValue)
Implements ICollection(Of KeyValuePair(Of TKey, TValue)), IDictionary, IDictionary(Of TKey, TValue), IEnumerable(Of KeyValuePair(Of TKey, TValue)), IReadOnlyCollection(Of KeyValuePair(Of TKey, TValue)), IReadOnlyDictionary(Of TKey, TValue)

Public Class SortedList(Of TKey, TValue)
Implements ICollection(Of KeyValuePair(Of TKey, TValue)), IDictionary, IDictionary(Of TKey, TValue), IEnumerable(Of KeyValuePair(Of TKey, TValue))

Parametri di tipo

Ereditarietà

Object

SortedList<TKey,TValue>

Derivato

System.IdentityModel.Metadata.IndexedProtocolEndpointDictionary

Attributi

ComVisibleAttribute SerializableAttribute

Implementazioni

ICollection<KeyValuePair<TKey,TValue>> IDictionary<TKey,TValue> IEnumerable<KeyValuePair<TKey,TValue>> IEnumerable<T> IReadOnlyCollection<KeyValuePair<TKey,TValue>> IReadOnlyDictionary<TKey,TValue> ICollection IDictionary IEnumerable

Esempio

Nell'esempio di codice seguente viene creata una SortedList<TKey,TValue> vuota di stringhe con chiavi stringa e viene usato il metodo Add per aggiungere alcuni elementi. Nell'esempio viene illustrato che il metodo Add genera un ArgumentException quando si tenta di aggiungere una chiave duplicata.

Nell'esempio viene usata la proprietà Item[] (l'indicizzatore in C#) per recuperare i valori, dimostrando che un KeyNotFoundException viene generato quando una chiave richiesta non è presente e indica che il valore associato a una chiave può essere sostituito.

Nell'esempio viene illustrato come utilizzare il metodo TryGetValue come metodo più efficiente per recuperare i valori se un programma spesso deve provare i valori chiave non inclusi nell'elenco ordinato e illustra come usare il metodo ContainsKey per verificare se esiste una chiave prima di chiamare il metodo Add.

Nell'esempio viene illustrato come enumerare le chiavi e i valori nell'elenco ordinato e come enumerare solo le chiavi e i valori usando la proprietà Keys e la proprietà Values.

Infine, l'esempio illustra il metodo Remove.

#using <System.dll>

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

public ref class Example
{
public:
    static void Main()
    {
        // Create a new sorted list of strings, with string
        // keys.
        SortedList<String^, String^>^ openWith =
            gcnew SortedList<String^, String^>();

        // Add some elements to the list. There are no 
        // duplicate keys, but some of the values are duplicates.
        openWith->Add("txt", "notepad.exe");
        openWith->Add("bmp", "paint.exe");
        openWith->Add("dib", "paint.exe");
        openWith->Add("rtf", "wordpad.exe");

        // The Add method throws an exception if the new key is
        // already in the list.
        try
        {
            openWith->Add("txt", "winword.exe");
        }
        catch (ArgumentException^)
        {
            Console::WriteLine("An element with Key = \"txt\" already exists.");
        }

        // The Item property is another name for the indexer, so you
        // can omit its name when accessing elements.
        Console::WriteLine("For key = \"rtf\", value = {0}.",
            openWith["rtf"]);

        // The indexer can be used to change the value associated
        // with a key.
        openWith["rtf"] = "winword.exe";
        Console::WriteLine("For key = \"rtf\", value = {0}.",
            openWith["rtf"]);

        // If a key does not exist, setting the indexer for that key
        // adds a new key/value pair.
        openWith["doc"] = "winword.exe";

        // The indexer throws an exception if the requested key is
        // not in the list.
        try
        {
            Console::WriteLine("For key = \"tif\", value = {0}.",
                openWith["tif"]);
        }
        catch (KeyNotFoundException^)
        {
            Console::WriteLine("Key = \"tif\" is not found.");
        }

        // When a program often has to try keys that turn out not to
        // be in the list, TryGetValue can be a more efficient
        // way to retrieve values.
        String^ value = "";
        if (openWith->TryGetValue("tif", value))
        {
            Console::WriteLine("For key = \"tif\", value = {0}.", value);
        }
        else
        {
            Console::WriteLine("Key = \"tif\" is not found.");
        }

        // ContainsKey can be used to test keys before inserting
        // them.
        if (!openWith->ContainsKey("ht"))
        {
            openWith->Add("ht", "hypertrm.exe");
            Console::WriteLine("Value added for key = \"ht\": {0}",
                openWith["ht"]);
        }

        // When you use foreach to enumerate list elements,
        // the elements are retrieved as KeyValuePair objects.
        Console::WriteLine();
        for each( KeyValuePair<String^, String^> kvp in openWith )
        {
            Console::WriteLine("Key = {0}, Value = {1}",
                kvp.Key, kvp.Value);
        }

        // To get the values alone, use the Values property.
        IList<String^>^ ilistValues = openWith->Values;

        // The elements of the list are strongly typed with the
        // type that was specified for the SortedList values.
        Console::WriteLine();
        for each( String^ s in ilistValues )
        {
            Console::WriteLine("Value = {0}", s);
        }

        // The Values property is an efficient way to retrieve
        // values by index.
        Console::WriteLine("\nIndexed retrieval using the Values " +
            "property: Values[2] = {0}", openWith->Values[2]);

        // To get the keys alone, use the Keys property.
        IList<String^>^ ilistKeys = openWith->Keys;

        // The elements of the list are strongly typed with the
        // type that was specified for the SortedList keys.
        Console::WriteLine();
        for each( String^ s in ilistKeys )
        {
            Console::WriteLine("Key = {0}", s);
        }

        // The Keys property is an efficient way to retrieve
        // keys by index.
        Console::WriteLine("\nIndexed retrieval using the Keys " +
            "property: Keys[2] = {0}", openWith->Keys[2]);

        // Use the Remove method to remove a key/value pair.
        Console::WriteLine("\nRemove(\"doc\")");
        openWith->Remove("doc");

        if (!openWith->ContainsKey("doc"))
        {
            Console::WriteLine("Key \"doc\" is not found.");
        }
    }
};

int main()
{
    Example::Main();
}

/* This code example produces the following output:

An element with Key = "txt" already exists.
For key = "rtf", value = wordpad.exe.
For key = "rtf", value = winword.exe.
Key = "tif" is not found.
Key = "tif" is not found.
Value added for key = "ht": hypertrm.exe

Key = bmp, Value = paint.exe
Key = dib, Value = paint.exe
Key = doc, Value = winword.exe
Key = ht, Value = hypertrm.exe
Key = rtf, Value = winword.exe
Key = txt, Value = notepad.exe

Value = paint.exe
Value = paint.exe
Value = winword.exe
Value = hypertrm.exe
Value = winword.exe
Value = notepad.exe

Indexed retrieval using the Values property: Values[2] = winword.exe

Key = bmp
Key = dib
Key = doc
Key = ht
Key = rtf
Key = txt

Indexed retrieval using the Keys property: Keys[2] = doc

Remove("doc")
Key "doc" is not found.
 */

using System;
using System.Collections.Generic;

public class Example
{
    public static void Main()
    {
        // Create a new sorted list of strings, with string
        // keys.
        SortedList<string, string> openWith =
            new SortedList<string, string>();

        // Add some elements to the list. There are no
        // duplicate keys, but some of the values are duplicates.
        openWith.Add("txt", "notepad.exe");
        openWith.Add("bmp", "paint.exe");
        openWith.Add("dib", "paint.exe");
        openWith.Add("rtf", "wordpad.exe");

        // The Add method throws an exception if the new key is
        // already in the list.
        try
        {
            openWith.Add("txt", "winword.exe");
        }
        catch (ArgumentException)
        {
            Console.WriteLine("An element with Key = \"txt\" already exists.");
        }

        // The Item property is another name for the indexer, so you
        // can omit its name when accessing elements.
        Console.WriteLine("For key = \"rtf\", value = {0}.",
            openWith["rtf"]);

        // The indexer can be used to change the value associated
        // with a key.
        openWith["rtf"] = "winword.exe";
        Console.WriteLine("For key = \"rtf\", value = {0}.",
            openWith["rtf"]);

        // If a key does not exist, setting the indexer for that key
        // adds a new key/value pair.
        openWith["doc"] = "winword.exe";

        // The indexer throws an exception if the requested key is
        // not in the list.
        try
        {
            Console.WriteLine("For key = \"tif\", value = {0}.",
                openWith["tif"]);
        }
        catch (KeyNotFoundException)
        {
            Console.WriteLine("Key = \"tif\" is not found.");
        }

        // When a program often has to try keys that turn out not to
        // be in the list, TryGetValue can be a more efficient
        // way to retrieve values.
        string value = "";
        if (openWith.TryGetValue("tif", out value))
        {
            Console.WriteLine("For key = \"tif\", value = {0}.", value);
        }
        else
        {
            Console.WriteLine("Key = \"tif\" is not found.");
        }

        // ContainsKey can be used to test keys before inserting
        // them.
        if (!openWith.ContainsKey("ht"))
        {
            openWith.Add("ht", "hypertrm.exe");
            Console.WriteLine("Value added for key = \"ht\": {0}",
                openWith["ht"]);
        }

        // When you use foreach to enumerate list elements,
        // the elements are retrieved as KeyValuePair objects.
        Console.WriteLine();
        foreach( KeyValuePair<string, string> kvp in openWith )
        {
            Console.WriteLine("Key = {0}, Value = {1}",
                kvp.Key, kvp.Value);
        }

        // To get the values alone, use the Values property.
        IList<string> ilistValues = openWith.Values;

        // The elements of the list are strongly typed with the
        // type that was specified for the SortedList values.
        Console.WriteLine();
        foreach( string s in ilistValues )
        {
            Console.WriteLine("Value = {0}", s);
        }

        // The Values property is an efficient way to retrieve
        // values by index.
        Console.WriteLine("\nIndexed retrieval using the Values " +
            "property: Values[2] = {0}", openWith.Values[2]);

        // To get the keys alone, use the Keys property.
        IList<string> ilistKeys = openWith.Keys;

        // The elements of the list are strongly typed with the
        // type that was specified for the SortedList keys.
        Console.WriteLine();
        foreach( string s in ilistKeys )
        {
            Console.WriteLine("Key = {0}", s);
        }

        // The Keys property is an efficient way to retrieve
        // keys by index.
        Console.WriteLine("\nIndexed retrieval using the Keys " +
            "property: Keys[2] = {0}", openWith.Keys[2]);

        // Use the Remove method to remove a key/value pair.
        Console.WriteLine("\nRemove(\"doc\")");
        openWith.Remove("doc");

        if (!openWith.ContainsKey("doc"))
        {
            Console.WriteLine("Key \"doc\" is not found.");
        }
    }
}

/* This code example produces the following output:

An element with Key = "txt" already exists.
For key = "rtf", value = wordpad.exe.
For key = "rtf", value = winword.exe.
Key = "tif" is not found.
Key = "tif" is not found.
Value added for key = "ht": hypertrm.exe

Key = bmp, Value = paint.exe
Key = dib, Value = paint.exe
Key = doc, Value = winword.exe
Key = ht, Value = hypertrm.exe
Key = rtf, Value = winword.exe
Key = txt, Value = notepad.exe

Value = paint.exe
Value = paint.exe
Value = winword.exe
Value = hypertrm.exe
Value = winword.exe
Value = notepad.exe

Indexed retrieval using the Values property: Values[2] = winword.exe

Key = bmp
Key = dib
Key = doc
Key = ht
Key = rtf
Key = txt

Indexed retrieval using the Keys property: Keys[2] = doc

Remove("doc")
Key "doc" is not found.
 */

Imports System.Collections.Generic

Public Class Example
    
    Public Shared Sub Main() 

        ' Create a new sorted list of strings, with string 
        ' keys. 
        Dim openWith As New SortedList(Of String, String)
        
        ' Add some elements to the list. There are no 
        ' duplicate keys, but some of the values are duplicates.
        openWith.Add("txt", "notepad.exe")
        openWith.Add("bmp", "paint.exe")
        openWith.Add("dib", "paint.exe")
        openWith.Add("rtf", "wordpad.exe")
        
        ' The Add method throws an exception if the new key is 
        ' already in the list.
        Try
            openWith.Add("txt", "winword.exe")
        Catch 
            Console.WriteLine("An element with Key = ""txt"" already exists.")
        End Try

        ' The Item property is the default property, so you 
        ' can omit its name when accessing elements. 
        Console.WriteLine("For key = ""rtf"", value = {0}.", _
            openWith("rtf"))
        
        ' The default Item property can be used to change the value
        ' associated with a key.
        openWith("rtf") = "winword.exe"
        Console.WriteLine("For key = ""rtf"", value = {0}.", _
            openWith("rtf"))
        
        ' If a key does not exist, setting the default Item property
        ' for that key adds a new key/value pair.
        openWith("doc") = "winword.exe"

        ' The default Item property throws an exception if the requested
        ' key is not in the list.
        Try
            Console.WriteLine("For key = ""tif"", value = {0}.", _
                openWith("tif"))
        Catch 
            Console.WriteLine("Key = ""tif"" is not found.")
        End Try

        ' When a program often has to try keys that turn out not to
        ' be in the list, TryGetValue can be a more efficient 
        ' way to retrieve values.
        Dim value As String = ""
        If openWith.TryGetValue("tif", value) Then
            Console.WriteLine("For key = ""tif"", value = {0}.", value)
        Else
            Console.WriteLine("Key = ""tif"" is not found.")
        End If

        ' ContainsKey can be used to test keys before inserting 
        ' them.
        If Not openWith.ContainsKey("ht") Then
            openWith.Add("ht", "hypertrm.exe")
            Console.WriteLine("Value added for key = ""ht"": {0}", _
                openWith("ht"))
        End If

        ' When you use foreach to enumerate list elements,
        ' the elements are retrieved as KeyValuePair objects.
        Console.WriteLine()
        For Each kvp As KeyValuePair(Of String, String) In openWith
            Console.WriteLine("Key = {0}, Value = {1}", _
                kvp.Key, kvp.Value)
        Next kvp

        ' To get the values alone, use the Values property.
        Dim ilistValues As IList(Of String) = openWith.Values
        
        ' The elements of the list are strongly typed with the
        ' type that was specified for the SortedList values.
        Console.WriteLine()
        For Each s As String In ilistValues
            Console.WriteLine("Value = {0}", s)
        Next s

        ' The Values property is an efficient way to retrieve
        ' values by index.
        Console.WriteLine(vbLf & "Indexed retrieval using the " & _
            "Values property: Values(2) = {0}", openWith.Values(2))

        ' To get the keys alone, use the Keys property.
        Dim ilistKeys As IList(Of String) = openWith.Keys
        
        ' The elements of the list are strongly typed with the
        ' type that was specified for the SortedList keys.
        Console.WriteLine()
        For Each s As String In ilistKeys 
            Console.WriteLine("Key = {0}", s)
        Next s

        ' The Keys property is an efficient way to retrieve
        ' keys by index.
        Console.WriteLine(vbLf & "Indexed retrieval using the " & _
            "Keys property: Keys(2) = {0}", openWith.Keys(2))

        ' Use the Remove method to remove a key/value pair.
        Console.WriteLine(vbLf + "Remove(""doc"")")
        openWith.Remove("doc")
        
        If Not openWith.ContainsKey("doc") Then
            Console.WriteLine("Key ""doc"" is not found.")
        End If

    End Sub

End Class

' This code example produces the following output:
'
'An element with Key = "txt" already exists.
'For key = "rtf", value = wordpad.exe.
'For key = "rtf", value = winword.exe.
'Key = "tif" is not found.
'Key = "tif" is not found.
'Value added for key = "ht": hypertrm.exe
'
'Key = bmp, Value = paint.exe
'Key = dib, Value = paint.exe
'Key = doc, Value = winword.exe
'Key = ht, Value = hypertrm.exe
'Key = rtf, Value = winword.exe
'Key = txt, Value = notepad.exe
'
'Value = paint.exe
'Value = paint.exe
'Value = winword.exe
'Value = hypertrm.exe
'Value = winword.exe
'Value = notepad.exe
'
'Indexed retrieval using the Values property: Values(2) = winword.exe
'
'Key = bmp
'Key = dib
'Key = doc
'Key = ht
'Key = rtf
'Key = txt
'
'Indexed retrieval using the Keys property: Keys(2) = doc
'
'Remove("doc")
'Key "doc" is not found.
'

open System
open System.Collections.Generic

// Create a new sorted list of strings, with string
// keys.
let openWith = SortedList<string, string>()

// Add some elements to the list. There are no
// duplicate keys, but some of the values are duplicates.
openWith.Add("txt", "notepad.exe")
openWith.Add("bmp", "paint.exe")
openWith.Add("dib", "paint.exe")
openWith.Add("rtf", "wordpad.exe")

// The Add method throws an exception if the new key is
// already in the list.
try
    openWith.Add("txt", "winword.exe");
with
    | :? ArgumentException ->
        printfn "An element with Key = \"txt\" already exists."

// The Item property is another name for the indexer, so you
// can omit its name when accessing elements.
printfn $"""For key = "rtf", value = {openWith["rtf"]}."""

// The indexer can be used to change the value associated
// with a key.
openWith["rtf"] <- "winword.exe"
printfn $"""For key = "rtf", value = {openWith["rtf"]}."""

// If a key does not exist, setting the indexer for that key
// adds a new key/value pair.
openWith["doc"] <- "winword.exe";

// The indexer throws an exception if the requested key is
// not in the list.
try
    printfn $"""For key = "tif", value = {openWith["tif"]}."""
with 
    | :? KeyNotFoundException ->
        printfn "Key = \"tif\" is not found."

// When a program often has to try keys that turn out not to
// be in the list, TryGetValue can be a more efficient
// way to retrieve values.
match openWith.TryGetValue("tif") with
| true, value ->
    printfn "For key = \"tif\", value = {value}."
| false, _ ->
    printfn "Key = \"tif\" is not found."

// ContainsKey can be used to test keys before inserting
// them.
if not (openWith.ContainsKey("ht")) then
    openWith.Add("ht", "hypertrm.exe");
    printfn """Value added for key = "ht": {openWith["ht"]}"""

// When you use foreach to enumerate list elements,
// the elements are retrieved as KeyValuePair objects.
Console.WriteLine()
for kvp in openWith do
    printfn $"Key = {kvp.Key}, Value = {kvp.Value}"

// To get the values alone, use the Values property.
let ilistValues = openWith.Values;

// The elements of the list are strongly typed with the
// type that was specified for the SortedList values.
Console.WriteLine()
for s in ilistValues do
    printfn $"Value = {s}"

// The Values property is an efficient way to retrieve
// values by index.
printf "\nIndexed retrieval using the Values "
printfn $"property: Values[2] = {openWith.Values[2]}"

// To get the keys alone, use the Keys property.
let ilistKeys = openWith.Keys;

// The elements of the list are strongly typed with the
// type that was specified for the SortedList keys.
Console.WriteLine()
for s in ilistKeys do
    printfn $"Key = {s}"

// The Keys property is an efficient way to retrieve
// keys by index.
printf "\nIndexed retrieval using the Keys "
printfn $"property: Keys[2] = {openWith.Keys[2]}"

// Use the Remove method to remove a key/value pair.
printfn "\nRemove(\"doc\")"
openWith.Remove("doc") |> ignore

if not (openWith.ContainsKey("doc")) then
    printfn "Key \"doc\" is not found."

(* This code example produces the following output:

An element with Key = "txt" already exists.
For key = "rtf", value = wordpad.exe.
For key = "rtf", value = winword.exe.
Key = "tif" is not found.
Key = "tif" is not found.
Value added for key = "ht": hypertrm.exe

Key = bmp, Value = paint.exe
Key = dib, Value = paint.exe
Key = doc, Value = winword.exe
Key = ht, Value = hypertrm.exe
Key = rtf, Value = winword.exe
Key = txt, Value = notepad.exe

Value = paint.exe
Value = paint.exe
Value = winword.exe
Value = hypertrm.exe
Value = winword.exe
Value = notepad.exe

Indexed retrieval using the Values property: Values[2] = winword.exe

Key = bmp
Key = dib
Key = doc
Key = ht
Key = rtf
Key = txt

Indexed retrieval using the Keys property: Keys[2] = doc

Remove("doc")
Key "doc" is not found.
 *)

Commenti

La classe generica SortedList<TKey,TValue> è una matrice di coppie chiave/valore con il recupero di O(log n), dove n è il numero di elementi nel dizionario. In questo caso, è simile alla classe generica SortedDictionary<TKey,TValue>. Le due classi hanno modelli a oggetti simili e hanno entrambi il recupero di O(log n). Dove le due classi differiscono è l'uso della memoria e la velocità di inserimento e rimozione:

• SortedList<TKey,TValue> usa meno memoria di SortedDictionary<TKey,TValue>.

• SortedDictionary<TKey,TValue> offre operazioni di inserimento e rimozione più veloci per i dati non ordinamento, O(log n) anziché O(n) per SortedList<TKey,TValue>.

• Se l'elenco viene popolato tutti contemporaneamente da dati ordinati, SortedList<TKey,TValue> è più veloce di SortedDictionary<TKey,TValue>.

Un'altra differenza tra le classi SortedDictionary<TKey,TValue> e SortedList<TKey,TValue> consiste nel fatto che SortedList<TKey,TValue> supporta un efficiente recupero indicizzato di chiavi e valori tramite le raccolte restituite dalle proprietà Keys e Values. Non è necessario rigenerare gli elenchi quando si accede alle proprietà, perché gli elenchi sono solo wrapper per le matrici interne di chiavi e valori. Il codice seguente illustra l'uso della proprietà Values per il recupero indicizzato di valori da un elenco ordinato di stringhe:

String^ v = mySortedList->Values[3];

string v = mySortedList.Values[3];

Dim v As String = mySortedList.Values(3)

let v = mySortedList.Values[3]

SortedList<TKey,TValue> viene implementato come matrice di coppie chiave/valore, ordinate in base alla chiave. Ogni elemento può essere recuperato come oggetto KeyValuePair<TKey,TValue>.

Gli oggetti chiave devono essere non modificabili purché vengano usati come chiavi nel SortedList<TKey,TValue>. Ogni chiave in un SortedList<TKey,TValue> deve essere univoca. Una chiave non può essere null, ma un valore può essere, se il tipo di valori nell'elenco, TValue, è un tipo riferimento.

SortedList<TKey,TValue> richiede un'implementazione dell'operatore di confronto per ordinare ed eseguire confronti. L'operatore di confronto predefinito Comparer<T>.Default controlla se il tipo di chiave TKey implementa System.IComparable<T> e usa tale implementazione, se disponibile. In caso contrario, Comparer<T>.Default controlla se il tipo di chiave TKey implementa System.IComparable. Se il tipo di chiave TKey non implementa alcuna interfaccia, è possibile specificare un'implementazione System.Collections.Generic.IComparer<T> in un overload del costruttore che accetta un parametro comparer.

La capacità di un SortedList<TKey,TValue> è il numero di elementi che il SortedList<TKey,TValue> può contenere. Man mano che gli elementi vengono aggiunti a un SortedList<TKey,TValue>, la capacità viene aumentata automaticamente come richiesto dalla riallocazione della matrice interna. La capacità può essere ridotta chiamando TrimExcess o impostando la proprietà Capacity in modo esplicito. La riduzione della capacità rialloca la memoria e copia tutti gli elementi nella SortedList<TKey,TValue>.

solo .NET Framework: Per oggetti SortedList<TKey,TValue> di grandi dimensioni, è possibile aumentare la capacità massima a 2 miliardi di elementi in un sistema a 64 bit impostando l'attributo enabled dell'elemento di configurazione <gcAllowVeryLargeObjects> su true nell'ambiente di runtime.

L'istruzione foreach del linguaggio C# (for each in C++, For Each in Visual Basic) restituisce un oggetto del tipo degli elementi nell'insieme. Poiché gli elementi della SortedList<TKey,TValue> sono coppie chiave/valore, il tipo di elemento non è il tipo della chiave o il tipo del valore. Al contrario, il tipo di elemento è KeyValuePair<TKey,TValue>. Per esempio:

for each( KeyValuePair<int, String^> kvp in mySortedList )
{
    Console::WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
}

foreach( KeyValuePair<int, string> kvp in mySortedList )
{
    Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
}

For Each kvp As KeyValuePair(Of Integer, String) In mySortedList
    Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value)
Next kvp

for kvp in mySortedList do
    printfn $"Key = {kvp.Key}, Value = {kvp.Value}"

L'istruzione foreach è un wrapper intorno all'enumeratore, che consente solo la lettura, non la scrittura nella raccolta.

Costruttori

Proprietà

Metodi

Implementazioni dell'interfaccia esplicita

Metodi di estensione

Si applica a

Thread safety

I membri statici pubblici (Shared in Visual Basic) di questo tipo sono thread-safe. Non è garantito che tutti i membri dell'istanza siano thread-safe.

Un SortedList<TKey,TValue> può supportare contemporaneamente più lettori, purché la raccolta non venga modificata. Anche in questo caso, l'enumerazione tramite una raccolta non è intrinsecamente una procedura thread-safe. Per garantire la thread safety durante l'enumerazione, è possibile bloccare la raccolta durante l'intera enumerazione. Per consentire l'accesso alla raccolta da parte di più thread per la lettura e la scrittura, è necessario implementare la propria sincronizzazione.

Vedi anche

• IDictionary<TKey,TValue>
• Dictionary<TKey,TValue>
• SortedDictionary<TKey,TValue>
• KeyValuePair<TKey,TValue>
• IComparer<T>