Enumerable.All(IEnumerable<TSource>, Func<TSource,Boolean>) Enumerable.All(IEnumerable<TSource>, Func<TSource,Boolean>) Enumerable.All(IEnumerable<TSource>, Func<TSource,Boolean>) Enumerable.All(IEnumerable<TSource>, Func<TSource,Boolean>) Method

定義

シーケンスのすべての要素が条件を満たしているかどうかを判断します。Determines whether all elements of a sequence satisfy a condition.

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

型パラメーター

TSource

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

パラメーター

source
IEnumerable<TSource>

述語を適用する要素を格納している IEnumerable<T>An IEnumerable<T> that contains the elements to apply the predicate to.

predicate
Func<TSource,Boolean>

各要素が条件を満たしているかどうかをテストする関数。A function to test each element for a condition.

戻り値

指定された述語でソース シーケンスのすべての要素がテストに合格する場合は true。それ以外の場合は falsetrue if every element of the source sequence passes the test in the specified predicate, or if the sequence is empty; otherwise, false.

例外

source または predicatenull です。source or predicate is null.

次のコード例は、使用する方法を示しますAllシーケンス内のすべての要素が条件を満たすかどうかを判断します。The following code example demonstrates how to use All to determine whether all the elements in a sequence satisfy a condition. 変数allStartWithBはすべて、ペットの名前が"B"で開始する場合、または場合、pets配列が空です。Variable allStartWithB is true if all the pet names start with "B" or if the pets array is empty.

class Pet
{
    public string Name { get; set; }
    public int Age { get; set; }
}

public static void AllEx()
{
    // Create an array of Pets.
    Pet[] pets = { new Pet { Name="Barley", Age=10 },
                   new Pet { Name="Boots", Age=4 },
                   new Pet { Name="Whiskers", Age=6 } };

    // Determine whether all pet names 
    // in the array start with 'B'.
    bool allStartWithB = pets.All(pet =>
                                      pet.Name.StartsWith("B"));

    Console.WriteLine(
        "{0} pet names start with 'B'.",
        allStartWithB ? "All" : "Not all");
}

// This code produces the following output:
//
//  Not all pet names start with 'B'.
Structure Pet
    Public Name As String
    Public Age As Integer
End Structure

Sub AllEx()
    ' Create an array of Pets.
    Dim pets() As Pet =
{New Pet With {.Name = "Barley", .Age = 2},
 New Pet With {.Name = "Boots", .Age = 4},
 New Pet With {.Name = "Whiskers", .Age = 7}}

    ' Determine whether all pet names in the array start with "B".
    Dim allNames As Boolean =
pets.All(Function(ByVal pet) pet.Name.StartsWith("B"))

    ' Display the output.
    Dim text As String = IIf(allNames, "All", "Not all")
    MsgBox(text & " pet names start with 'B'.")
End Sub

' This code produces the following output:
'
' Not all pet names start with 'B'.

ブール値をAllメソッドは、通常の述語で使用を返します、where句 (Where Visual Basic で句) またはへの直接呼び出し、Whereメソッド。The Boolean value that the All method returns is typically used in the predicate of a where clause (Where clause in Visual Basic) or a direct call to the Where method. 次の例では、このように使用、Allメソッド。The following example demonstrates this use of the All method.

class Pet
{
    public string Name { get; set; }
    public int Age { get; set; }
}
class Person
{
    public string LastName { get; set; }
    public Pet[] Pets { get; set; }
}

public static void AllEx2()
{
    List<Person> people = new List<Person>
        { new Person { LastName = "Haas",
                       Pets = new Pet[] { new Pet { Name="Barley", Age=10 },
                                          new Pet { Name="Boots", Age=14 },
                                          new Pet { Name="Whiskers", Age=6 }}},
          new Person { LastName = "Fakhouri",
                       Pets = new Pet[] { new Pet { Name = "Snowball", Age = 1}}},
          new Person { LastName = "Antebi",
                       Pets = new Pet[] { new Pet { Name = "Belle", Age = 8} }},
          new Person { LastName = "Philips",
                       Pets = new Pet[] { new Pet { Name = "Sweetie", Age = 2},
                                          new Pet { Name = "Rover", Age = 13}} }
        };

    // Determine which people have pets that are all older than 5.
    IEnumerable<string> names = from person in people
                                where person.Pets.All(pet => pet.Age > 5)
                                select person.LastName;

    foreach (string name in names)
    {
        Console.WriteLine(name);
    }

    /* This code produces the following output:
     * 
     * Haas
     * Antebi
     */
}
Structure Pet
    Public Name As String
    Public Age As Integer
End Structure

Structure Person
    Public LastName As String
    Public Pets() As Pet
End Structure

Sub AllEx2()
    Dim people As New List(Of Person)(New Person() _
{New Person With {.LastName = "Haas",
                  .Pets = New Pet() {New Pet With {.Name = "Barley", .Age = 10},
                                     New Pet With {.Name = "Boots", .Age = 14},
                                     New Pet With {.Name = "Whiskers", .Age = 6}}},
  New Person With {.LastName = "Fakhouri",
                   .Pets = New Pet() {New Pet With {.Name = "Snowball", .Age = 1}}},
  New Person With {.LastName = "Antebi",
                   .Pets = New Pet() {New Pet With {.Name = "Belle", .Age = 8}}},
  New Person With {.LastName = "Philips",
                   .Pets = New Pet() {New Pet With {.Name = "Sweetie", .Age = 2},
                                      New Pet With {.Name = "Rover", .Age = 13}}}})

    ' Determine which people have pets that are all older than 5.
    Dim names = From person In people
                Where person.Pets.All(Function(pet) pet.Age > 5)
                Select person.LastName

    For Each name As String In names
        Console.WriteLine(name)
    Next

    ' This code produces the following output:
    '
    ' Haas
    ' Antebi

End Sub

注釈

注意

このメソッドには、コレクションのすべての要素は返しません。This method does not return all the elements of a collection. 代わりに、コレクションのすべての要素が条件を満たすかどうかを決定します。Instead, it determines whether all the elements of a collection satisfy a condition.

列挙体sourceが停止しているは、結果を判断できるようになります。The enumeration of source is stopped as soon as the result can be determined.

Visual Basic のクエリ式の構文、Aggregate Into All()の呼び出しに変換句Allします。In Visual Basic query expression syntax, an Aggregate Into All() clause translates to an invocation of All.

適用対象

こちらもご覧ください