Enumerable.ToDictionary Método

Definição

Namespace:
System.Linq
Assembly:
System.Linq.dll
Assembly:
System.Core.dll
Assembly:
netstandard.dll

Cria um Dictionary<TKey,TValue> de um IEnumerable<T>.Creates a Dictionary<TKey,TValue> from an IEnumerable<T>.

Sobrecargas

ToDictionary<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>)

Cria um Dictionary<TKey,TValue> de um IEnumerable<T>, de acordo com as funções especificadas de seletor de chave e seletor de elemento.Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to specified key selector and element selector functions.
ToDictionary<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>)

Cria um Dictionary<TKey,TValue> de um IEnumerable<T> de acordo com uma função de seletor de chave, um comparador e uma função de seletor de elemento especificados.Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to a specified key selector function, a comparer, and an element selector function.
ToDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)

Cria um Dictionary<TKey,TValue> de um IEnumerable<T>, de acordo com uma função de seletor de chave especificada.Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to a specified key selector function.
ToDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>)

Cria um Dictionary<TKey,TValue> de um IEnumerable<T>, de acordo com uma função de seletor de chave especificada e um comparador de chaves.Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to a specified key selector function and key comparer.

ToDictionary<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>)

Cria um Dictionary<TKey,TValue> de um IEnumerable<T>, de acordo com as funções especificadas de seletor de chave e seletor de elemento.Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to specified key selector and element selector functions.

public:
generic <typename TSource, typename TKey, typename TElement>
[System::Runtime::CompilerServices::Extension]
 static System::Collections::Generic::Dictionary<TKey, TElement> ^ ToDictionary(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, TKey> ^ keySelector, Func<TSource, TElement> ^ elementSelector);
public static System.Collections.Generic.Dictionary<TKey,TElement> ToDictionary<TSource,TKey,TElement> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,TKey> keySelector, Func<TSource,TElement> elementSelector);
static member ToDictionary : seq<'Source> * Func<'Source, 'Key> * Func<'Source, 'Element> -> System.Collections.Generic.Dictionary<'Key, 'Element>
<Extension()>
Public Function ToDictionary(Of TSource, TKey, TElement) (source As IEnumerable(Of TSource), keySelector As Func(Of TSource, TKey), elementSelector As Func(Of TSource, TElement)) As Dictionary(Of TKey, TElement)

Parâmetros de tipo

TSource

O tipo dos elementos de source.The type of the elements of source.

TKey

O tipo da chave retornada por keySelector.The type of the key returned by keySelector.

TElement

O tipo do valor retornado por elementSelector.The type of the value returned by elementSelector.

Parâmetros

source
IEnumerable<TSource>

Um IEnumerable<T> por meio do qual um Dictionary<TKey,TValue> será criado.An IEnumerable<T> to create a Dictionary<TKey,TValue> from.

keySelector
Func<TSource,TKey>

Uma função para extrair uma chave de cada elemento.A function to extract a key from each element.

elementSelector
Func<TSource,TElement>

Uma função de transformação para produzir um valor de elemento de resultado de cada elemento.A transform function to produce a result element value from each element.

Retornos

Dictionary<TKey,TElement>

Um Dictionary<TKey,TValue> que contém valores do tipo TElement selecionados da sequência de entrada.A Dictionary<TKey,TValue> that contains values of type TElement selected from the input sequence.

Exceções

ArgumentNullException

source, keySelector ou elementSelector é null.source or keySelector or elementSelector is null.

- ou --or- keySelector gera uma chave que é null.keySelector produces a key that is null.

ArgumentException

keySelector gera chaves duplicatas para dois elementos.keySelector produces duplicate keys for two elements.

Comentários

O ToDictionary<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>) método usa o Default comparador de igualdade padrão para comparar as chaves.The ToDictionary<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>) method uses the default equality comparer Default to compare keys.

Aplica-se a

ToDictionary<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>)

Cria um Dictionary<TKey,TValue> de um IEnumerable<T> de acordo com uma função de seletor de chave, um comparador e uma função de seletor de elemento especificados.Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to a specified key selector function, a comparer, and an element selector function.

public:
generic <typename TSource, typename TKey, typename TElement>
[System::Runtime::CompilerServices::Extension]
 static System::Collections::Generic::Dictionary<TKey, TElement> ^ ToDictionary(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, TKey> ^ keySelector, Func<TSource, TElement> ^ elementSelector, System::Collections::Generic::IEqualityComparer<TKey> ^ comparer);
public static System.Collections.Generic.Dictionary<TKey,TElement> ToDictionary<TSource,TKey,TElement> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,TKey> keySelector, Func<TSource,TElement> elementSelector, System.Collections.Generic.IEqualityComparer<TKey> comparer);
public static System.Collections.Generic.Dictionary<TKey,TElement> ToDictionary<TSource,TKey,TElement> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,TKey> keySelector, Func<TSource,TElement> elementSelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer);
static member ToDictionary : seq<'Source> * Func<'Source, 'Key> * Func<'Source, 'Element> * System.Collections.Generic.IEqualityComparer<'Key> -> System.Collections.Generic.Dictionary<'Key, 'Element>
<Extension()>
Public Function ToDictionary(Of TSource, TKey, TElement) (source As IEnumerable(Of TSource), keySelector As Func(Of TSource, TKey), elementSelector As Func(Of TSource, TElement), comparer As IEqualityComparer(Of TKey)) As Dictionary(Of TKey, TElement)

Parâmetros de tipo

TSource

O tipo dos elementos de source.The type of the elements of source.

TKey

O tipo da chave retornada por keySelector.The type of the key returned by keySelector.

TElement

O tipo do valor retornado por elementSelector.The type of the value returned by elementSelector.

Parâmetros

source
IEnumerable<TSource>

Um IEnumerable<T> por meio do qual um Dictionary<TKey,TValue> será criado.An IEnumerable<T> to create a Dictionary<TKey,TValue> from.

keySelector
Func<TSource,TKey>

Uma função para extrair uma chave de cada elemento.A function to extract a key from each element.

elementSelector
Func<TSource,TElement>

Uma função de transformação para produzir um valor de elemento de resultado de cada elemento.A transform function to produce a result element value from each element.

comparer
IEqualityComparer<TKey>

Um IEqualityComparer<T> para comparar chaves.An IEqualityComparer<T> to compare keys.

Retornos

Dictionary<TKey,TElement>

Um Dictionary<TKey,TValue> que contém valores do tipo TElement selecionados da sequência de entrada.A Dictionary<TKey,TValue> that contains values of type TElement selected from the input sequence.

Exceções

ArgumentNullException

source, keySelector ou elementSelector é null.source or keySelector or elementSelector is null.

- ou --or- keySelector gera uma chave que é null.keySelector produces a key that is null.

ArgumentException

keySelector gera chaves duplicatas para dois elementos.keySelector produces duplicate keys for two elements.

Comentários

Se comparer for null , o Default comparador de igualdade padrão será usado para comparar as chaves.If comparer is null, the default equality comparer Default is used to compare keys.

Aplica-se a

ToDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)

Cria um Dictionary<TKey,TValue> de um IEnumerable<T>, de acordo com uma função de seletor de chave especificada.Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to a specified key selector function.

public:
generic <typename TSource, typename TKey>
[System::Runtime::CompilerServices::Extension]
 static System::Collections::Generic::Dictionary<TKey, TSource> ^ ToDictionary(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, TKey> ^ keySelector);
public static System.Collections.Generic.Dictionary<TKey,TSource> ToDictionary<TSource,TKey> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,TKey> keySelector);
static member ToDictionary : seq<'Source> * Func<'Source, 'Key> -> System.Collections.Generic.Dictionary<'Key, 'Source>
<Extension()>
Public Function ToDictionary(Of TSource, TKey) (source As IEnumerable(Of TSource), keySelector As Func(Of TSource, TKey)) As Dictionary(Of TKey, TSource)

Parâmetros de tipo

TSource

O tipo dos elementos de source.The type of the elements of source.

TKey

O tipo da chave retornada por keySelector.The type of the key returned by keySelector.

Parâmetros

source
IEnumerable<TSource>

Um IEnumerable<T> por meio do qual um Dictionary<TKey,TValue> será criado.An IEnumerable<T> to create a Dictionary<TKey,TValue> from.

keySelector
Func<TSource,TKey>

Uma função para extrair uma chave de cada elemento.A function to extract a key from each element.

Retornos

Dictionary<TKey,TSource>

Um Dictionary<TKey,TValue> que contém chaves e valores.A Dictionary<TKey,TValue> that contains keys and values. Os valores dentro de cada grupo estão na mesma ordem que no source.The values within each group are in the same order as in source.

Exceções

ArgumentNullException

source ou keySelector é null.source or keySelector is null.

- ou --or- keySelector gera uma chave que é null.keySelector produces a key that is null.

ArgumentException

keySelector gera chaves duplicatas para dois elementos.keySelector produces duplicate keys for two elements.

Exemplos

O exemplo de código a seguir demonstra como usar o ToDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>) para criar um Dictionary<TKey,TValue> usando um seletor de chave.The following code example demonstrates how to use ToDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>) to create a Dictionary<TKey,TValue> by using a key selector.

class Package
{
    public string Company { get; set; }
    public double Weight { get; set; }
    public long TrackingNumber { get; set; }
}

public static void ToDictionaryEx1()
{
    List<Package> packages =
        new List<Package>
            { new Package { Company = "Coho Vineyard", Weight = 25.2, TrackingNumber = 89453312L },
              new Package { Company = "Lucerne Publishing", Weight = 18.7, TrackingNumber = 89112755L },
              new Package { Company = "Wingtip Toys", Weight = 6.0, TrackingNumber = 299456122L },
              new Package { Company = "Adventure Works", Weight = 33.8, TrackingNumber = 4665518773L } };

    // Create a Dictionary of Package objects,
    // using TrackingNumber as the key.
    Dictionary<long, Package> dictionary =
        packages.ToDictionary(p => p.TrackingNumber);

    foreach (KeyValuePair<long, Package> kvp in dictionary)
    {
        Console.WriteLine(
            "Key {0}: {1}, {2} pounds",
            kvp.Key,
            kvp.Value.Company,
            kvp.Value.Weight);
    }
}

/*
 This code produces the following output:

 Key 89453312: Coho Vineyard, 25.2 pounds
 Key 89112755: Lucerne Publishing, 18.7 pounds
 Key 299456122: Wingtip Toys, 6 pounds
 Key 4665518773: Adventure Works, 33.8 pounds
*/

Structure Package
    Public Company As String
    Public Weight As Double
    Public TrackingNumber As Long
End Structure

Sub ToDictionaryEx1()
    ' Create a list of Package values.
    Dim packages As New List(Of Package)(New Package() _
     {New Package With
      {.Company = "Coho Vineyard", .Weight = 25.2, .TrackingNumber = 89453312L},
      New Package With
      {.Company = "Lucerne Publishing", .Weight = 18.7, .TrackingNumber = 89112755L},
      New Package With
      {.Company = "Wingtip Toys", .Weight = 6.0, .TrackingNumber = 299456122L},
      New Package With
      {.Company = "Adventure Works", .Weight = 33.8, .TrackingNumber = 4665518773L}})

    ' Create a Dictionary that contains Package values, 
    ' using TrackingNumber as the key.
    Dim dict As Dictionary(Of Long, Package) =
    packages.ToDictionary(Function(p) p.TrackingNumber)

    ' Display the results.
    Dim output As New System.Text.StringBuilder
    For Each kvp As KeyValuePair(Of Long, Package) In dict
        output.AppendLine("Key " & kvp.Key & ": " &
                      kvp.Value.Company & ", " &
                      kvp.Value.Weight & " pounds")
    Next
    Console.WriteLine(output.ToString())
End Sub

' This code produces the following output:
'
' Key 89453312: Coho Vineyard, 25.2 pounds
' Key 89112755: Lucerne Publishing, 18.7 pounds
' Key 299456122: Wingtip Toys, 6 pounds
' Key 4665518773: Adventure Works, 33.8 pounds

Comentários

O ToDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>) método usa o Default comparador de igualdade padrão para comparar as chaves.The ToDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>) method uses the default equality comparer Default to compare keys.

Aplica-se a

ToDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>)

Cria um Dictionary<TKey,TValue> de um IEnumerable<T>, de acordo com uma função de seletor de chave especificada e um comparador de chaves.Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to a specified key selector function and key comparer.

public:
generic <typename TSource, typename TKey>
[System::Runtime::CompilerServices::Extension]
 static System::Collections::Generic::Dictionary<TKey, TSource> ^ ToDictionary(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, TKey> ^ keySelector, System::Collections::Generic::IEqualityComparer<TKey> ^ comparer);
public static System.Collections.Generic.Dictionary<TKey,TSource> ToDictionary<TSource,TKey> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,TKey> keySelector, System.Collections.Generic.IEqualityComparer<TKey> comparer);
public static System.Collections.Generic.Dictionary<TKey,TSource> ToDictionary<TSource,TKey> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,TKey> keySelector, System.Collections.Generic.IEqualityComparer<TKey>? comparer);
static member ToDictionary : seq<'Source> * Func<'Source, 'Key> * System.Collections.Generic.IEqualityComparer<'Key> -> System.Collections.Generic.Dictionary<'Key, 'Source>
<Extension()>
Public Function ToDictionary(Of TSource, TKey) (source As IEnumerable(Of TSource), keySelector As Func(Of TSource, TKey), comparer As IEqualityComparer(Of TKey)) As Dictionary(Of TKey, TSource)

Parâmetros de tipo

TSource

O tipo dos elementos de source.The type of the elements of source.

TKey

O tipo das chaves retornadas por keySelector.The type of the keys returned by keySelector.

Parâmetros

source
IEnumerable<TSource>

Um IEnumerable<T> por meio do qual um Dictionary<TKey,TValue> será criado.An IEnumerable<T> to create a Dictionary<TKey,TValue> from.

keySelector
Func<TSource,TKey>

Uma função para extrair uma chave de cada elemento.A function to extract a key from each element.

comparer
IEqualityComparer<TKey>

Um IEqualityComparer<T> para comparar chaves.An IEqualityComparer<T> to compare keys.

Retornos

Dictionary<TKey,TSource>

Um Dictionary<TKey,TValue> que contém chaves e valores.A Dictionary<TKey,TValue> that contains keys and values. Os valores dentro de cada grupo estão na mesma ordem que no source.The values within each group are in the same order as in source.

Exceções

ArgumentNullException

source ou keySelector é null.source or keySelector is null.

- ou --or- keySelector gera uma chave que é null.keySelector produces a key that is null.

ArgumentException

keySelector gera chaves duplicatas para dois elementos.keySelector produces duplicate keys for two elements.

Comentários

Se comparer for null , o Default comparador de igualdade padrão será usado para comparar as chaves.If comparer is null, the default equality comparer Default is used to compare keys.

Aplica-se a