Enumerable.ToLookup Enumerable.ToLookup Enumerable.ToLookup Enumerable.ToLookup Method

定義

Lookup<TKey,TElement> からジェネリックの IEnumerable<T> を作成します。Creates a generic Lookup<TKey,TElement> from an IEnumerable<T>.

オーバーロード

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

指定されたキー セレクター関数および要素セレクター関数に従って、Lookup<TKey,TElement> から IEnumerable<T> を作成します。Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to specified key selector and element selector functions.

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

指定されたキー セレクター関数、比較子、および要素セレクター関数に従って、Lookup<TKey,TElement> から IEnumerable<T> を作成します。Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to a specified key selector function, a comparer and an element selector function.

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

指定されたキー セレクター関数に従って、Lookup<TKey,TElement> から IEnumerable<T> を作成します。Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to a specified key selector function.

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

指定されたキー セレクター関数およびキーの比較子に従って、Lookup<TKey,TElement> から IEnumerable<T> を作成します。Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to a specified key selector function and key comparer.

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

指定されたキー セレクター関数および要素セレクター関数に従って、Lookup<TKey,TElement> から IEnumerable<T> を作成します。Creates a Lookup<TKey,TElement> 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::Linq::ILookup<TKey, TElement> ^ ToLookup(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, TKey> ^ keySelector, Func<TSource, TElement> ^ elementSelector);
public static System.Linq.ILookup<TKey,TElement> ToLookup<TSource,TKey,TElement> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,TKey> keySelector, Func<TSource,TElement> elementSelector);
static member ToLookup : seq<'Source> * Func<'Source, 'Key> * Func<'Source, 'Element> -> System.Linq.ILookup<'Key, 'Element>
<Extension()>
Public Function ToLookup(Of TSource, TKey, TElement) (source As IEnumerable(Of TSource), keySelector As Func(Of TSource, TKey), elementSelector As Func(Of TSource, TElement)) As ILookup(Of TKey, TElement)

型パラメーター

TSource

source の要素の型。The type of the elements of source.

TKey

keySelector によって返されるキーの型。The type of the key returned by keySelector.

TElement

elementSelector によって返される値の型。The type of the value returned by elementSelector.

パラメーター

source
IEnumerable<TSource>

IEnumerable<T> の作成元の Lookup<TKey,TElement>The IEnumerable<T> to create a Lookup<TKey,TElement> from.

keySelector
Func<TSource,TKey>

各要素からキーを抽出する関数。A function to extract a key from each element.

elementSelector
Func<TSource,TElement>

各要素から結果の要素値を生成する変換関数。A transform function to produce a result element value from each element.

戻り値

入力シーケンスから選択された TElement 型の値を格納する Lookup<TKey,TElement>A Lookup<TKey,TElement> that contains values of type TElement selected from the input sequence.

例外

sourcekeySelector、または elementSelector は、null です。source or keySelector or elementSelector is null.

次のコード例は、使用する方法を示しますToLookup<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>)を作成する、Lookup<TKey,TElement>キー セレクター関数および要素セレクター関数を使用しています。The following code example demonstrates how to use ToLookup<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>) to create a Lookup<TKey,TElement> by using a key selector function and an element selector function.

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

public static void ToLookupEx1()
{
    // Create a list of Packages.
    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 = "Contoso Pharmaceuticals", 
                  Weight = 9.3, TrackingNumber = 670053128L },
              new Package { Company = "Wide World Importers", 
                  Weight = 33.8, TrackingNumber = 4665518773L } };

    // Create a Lookup to organize the packages. 
    // Use the first character of Company as the key value.
    // Select Company appended to TrackingNumber 
    // as the element values of the Lookup.
    ILookup<char, string> lookup =
        packages
        .ToLookup(p => Convert.ToChar(p.Company.Substring(0, 1)),
                  p => p.Company + " " + p.TrackingNumber);

    // Iterate through each IGrouping in the Lookup.
    foreach (IGrouping<char, string> packageGroup in lookup)
    {
        // Print the key value of the IGrouping.
        Console.WriteLine(packageGroup.Key);
        // Iterate through each value in the 
        // IGrouping and print its value.
        foreach (string str in packageGroup)
            Console.WriteLine("    {0}", str);
    }
}

/*
 This code produces the following output:

 C
     Coho Vineyard 89453312
     Contoso Pharmaceuticals 670053128
 L
     Lucerne Publishing 89112755
 W
     Wingtip Toys 299456122
     Wide World Importers 4665518773
*/
Structure Package
    Public Company As String
    Public Weight As Double
    Public TrackingNumber As Long
End Structure

Sub ToLookupEx1()
    ' Create a list of Packages.
    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 = "Contoso Pharmaceuticals", .Weight = 9.3, .TrackingNumber = 670053128L},
      New Package With
      {.Company = "Wide World Importers", .Weight = 33.8, .TrackingNumber = 4665518773L}})

    ' Create a Lookup to organize the packages. 
    ' Use the first character of Company as the key value.
    ' Select Company appended to TrackingNumber 
    ' as the element values of the Lookup.
    Dim lookup As ILookup(Of Char, String) =
    packages.ToLookup(Function(p) _
                          Convert.ToChar(p.Company.Substring(0, 1)),
                      Function(p) _
                          p.Company & " " & p.TrackingNumber)

    Dim output As New System.Text.StringBuilder

    ' Iterate through each IGrouping in the Lookup.
    For Each packageGroup As IGrouping(Of Char, String) In lookup
        ' Print the key value of the IGrouping.
        output.AppendLine(packageGroup.Key)
        ' Iterate through each value in the IGrouping and print its value.
        For Each str As String In packageGroup
            output.AppendLine("   " & str)
        Next
    Next

    ' Select a group of packages by indexing directly into the Lookup.
    Dim cgroup As IEnumerable(Of String) = lookup("C"c)

    output.AppendLine(vbCrLf & "Packages from Company names that start with 'C':")
    For Each str As String In cgroup
        output.AppendLine(str)
    Next

    ' Display the output.
    MsgBox(output.ToString())
End Sub

' This code produces the following output:
'
' C
'    Coho Vineyard 89453312
'    Contoso Pharmaceuticals 670053128
' L
'    Lucerne Publishing 89112755
' W
'    Wingtip Toys 299456122
'    Wide World Importers 4665518773
'
' Packages from Company names that start with 'C':
' Coho Vineyard 89453312
' Contoso Pharmaceuticals 670053128

注釈

ToLookup<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>)メソッドを返します。 をLookup<TKey,TElement>、値のコレクションにキーをマップする一対多の辞書。The ToLookup<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>) method returns a Lookup<TKey,TElement>, a one-to-many dictionary that maps keys to collections of values. ALookup<TKey,TElement>とは異なります、 Dictionary<TKey,TValue>、単一の値のキーの一対一のマッピングを実行します。A Lookup<TKey,TElement> differs from a Dictionary<TKey,TValue>, which performs a one-to-one mapping of keys to single values.

既定の等値比較子Defaultキーを比較するために使用します。The default equality comparer Default is used to compare keys.

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

指定されたキー セレクター関数、比較子、および要素セレクター関数に従って、Lookup<TKey,TElement> から IEnumerable<T> を作成します。Creates a Lookup<TKey,TElement> 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::Linq::ILookup<TKey, TElement> ^ ToLookup(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, TKey> ^ keySelector, Func<TSource, TElement> ^ elementSelector, System::Collections::Generic::IEqualityComparer<TKey> ^ comparer);
public static System.Linq.ILookup<TKey,TElement> ToLookup<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 ToLookup : seq<'Source> * Func<'Source, 'Key> * Func<'Source, 'Element> * System.Collections.Generic.IEqualityComparer<'Key> -> System.Linq.ILookup<'Key, 'Element>
<Extension()>
Public Function ToLookup(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 ILookup(Of TKey, TElement)

型パラメーター

TSource

source の要素の型。The type of the elements of source.

TKey

keySelector によって返されるキーの型。The type of the key returned by keySelector.

TElement

elementSelector によって返される値の型。The type of the value returned by elementSelector.

パラメーター

source
IEnumerable<TSource>

IEnumerable<T> の作成元の Lookup<TKey,TElement>The IEnumerable<T> to create a Lookup<TKey,TElement> from.

keySelector
Func<TSource,TKey>

各要素からキーを抽出する関数。A function to extract a key from each element.

elementSelector
Func<TSource,TElement>

各要素から結果の要素値を生成する変換関数。A transform function to produce a result element value from each element.

comparer
IEqualityComparer<TKey>

キーを比較する IEqualityComparer<T>An IEqualityComparer<T> to compare keys.

戻り値

入力シーケンスから選択された TElement 型の値を格納する Lookup<TKey,TElement>A Lookup<TKey,TElement> that contains values of type TElement selected from the input sequence.

例外

sourcekeySelector、または elementSelector は、null です。source or keySelector or elementSelector is null.

注釈

ToLookup<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>)メソッドを返します。 をLookup<TKey,TElement>、値のコレクションにキーをマップする一対多の辞書。The ToLookup<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>) method returns a Lookup<TKey,TElement>, a one-to-many dictionary that maps keys to collections of values. ALookup<TKey,TElement>とは異なります、 Dictionary<TKey,TValue>、単一の値のキーの一対一のマッピングを実行します。A Lookup<TKey,TElement> differs from a Dictionary<TKey,TValue>, which performs a one-to-one mapping of keys to single values.

場合comparernull、既定の等値比較子Defaultキーを比較するために使用します。If comparer is null, the default equality comparer Default is used to compare keys.

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

指定されたキー セレクター関数に従って、Lookup<TKey,TElement> から IEnumerable<T> を作成します。Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to a specified key selector function.

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

型パラメーター

TSource

source の要素の型。The type of the elements of source.

TKey

keySelector によって返されるキーの型。The type of the key returned by keySelector.

パラメーター

source
IEnumerable<TSource>

IEnumerable<T> の作成元の Lookup<TKey,TElement>The IEnumerable<T> to create a Lookup<TKey,TElement> from.

keySelector
Func<TSource,TKey>

各要素からキーを抽出する関数。A function to extract a key from each element.

戻り値

ILookup<TKey,TSource>

キーと値を格納している Lookup<TKey,TElement>A Lookup<TKey,TElement> that contains keys and values.

例外

source または keySelectornull です。source or keySelector is null.

注釈

ToLookup<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)メソッドを返します。 をLookup<TKey,TElement>、値のコレクションにキーをマップする一対多の辞書。The ToLookup<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>) method returns a Lookup<TKey,TElement>, a one-to-many dictionary that maps keys to collections of values. ALookup<TKey,TElement>とは異なります、 Dictionary<TKey,TValue>、単一の値のキーの一対一のマッピングを実行します。A Lookup<TKey,TElement> differs from a Dictionary<TKey,TValue>, which performs a one-to-one mapping of keys to single values.

既定の等値比較子Defaultキーを比較するために使用します。The default equality comparer Default is used to compare keys.

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

指定されたキー セレクター関数およびキーの比較子に従って、Lookup<TKey,TElement> から IEnumerable<T> を作成します。Creates a Lookup<TKey,TElement> 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::Linq::ILookup<TKey, TSource> ^ ToLookup(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, TKey> ^ keySelector, System::Collections::Generic::IEqualityComparer<TKey> ^ comparer);
public static System.Linq.ILookup<TKey,TSource> ToLookup<TSource,TKey> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,TKey> keySelector, System.Collections.Generic.IEqualityComparer<TKey> comparer);
static member ToLookup : seq<'Source> * Func<'Source, 'Key> * System.Collections.Generic.IEqualityComparer<'Key> -> System.Linq.ILookup<'Key, 'Source>
<Extension()>
Public Function ToLookup(Of TSource, TKey) (source As IEnumerable(Of TSource), keySelector As Func(Of TSource, TKey), comparer As IEqualityComparer(Of TKey)) As ILookup(Of TKey, TSource)

型パラメーター

TSource

source の要素の型。The type of the elements of source.

TKey

keySelector によって返されるキーの型。The type of the key returned by keySelector.

パラメーター

source
IEnumerable<TSource>

IEnumerable<T> の作成元の Lookup<TKey,TElement>The IEnumerable<T> to create a Lookup<TKey,TElement> from.

keySelector
Func<TSource,TKey>

各要素からキーを抽出する関数。A function to extract a key from each element.

comparer
IEqualityComparer<TKey>

キーを比較する IEqualityComparer<T>An IEqualityComparer<T> to compare keys.

戻り値

ILookup<TKey,TSource>

キーと値を格納している Lookup<TKey,TElement>A Lookup<TKey,TElement> that contains keys and values.

例外

source または keySelectornull です。source or keySelector is null.

注釈

ToLookup<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>)メソッドを返します。 をLookup<TKey,TElement>、値のコレクションにキーをマップする一対多の辞書。The ToLookup<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>) method returns a Lookup<TKey,TElement>, a one-to-many dictionary that maps keys to collections of values. ALookup<TKey,TElement>とは異なります、 Dictionary<TKey,TValue>、単一の値のキーの一対一のマッピングを実行します。A Lookup<TKey,TElement> is different to a Dictionary<TKey,TValue>, which performs a one-to-one mapping of keys to single values.

場合comparernull、既定の等値比較子Defaultキーを比較するために使用します。If comparer is null, the default equality comparer Default is used to compare keys.

適用対象