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

Definição

Determina se todos os elementos de uma sequência atendem a uma condição.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

Parâmetros de tipo

TSource

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

Parâmetros

source
IEnumerable<TSource>

Um IEnumerable<T> que contém os elementos aos quais o predicado será aplicado.An IEnumerable<T> that contains the elements to apply the predicate to.

predicate
Func<TSource,Boolean>

Uma função para testar cada elemento em relação a uma condição.A function to test each element for a condition.

Retornos

true se todos os elementos da sequência de origem passarem no teste no predicado especificado ou se a sequência for vazia; caso contrário, false.true if every element of the source sequence passes the test in the specified predicate, or if the sequence is empty; otherwise, false.

Exceções

source ou predicate é null.source or predicate is null.

Exemplos

O exemplo de código a seguir demonstra como usar All para determinar se todos os elementos em uma sequência satisfazem uma condição.The following code example demonstrates how to use All to determine whether all the elements in a sequence satisfy a condition. Variável allStartWithB é true se todos os nomes de animal de estimação iniciar com "B" ou se o pets matriz está vazia.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'.

O valor booleano que o All método retorna, normalmente é usada no predicado de um where cláusula (Where cláusula no Visual Basic) ou uma chamada direta para o Where método.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. O exemplo a seguir demonstra o uso do All método.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

Comentários

Observação

Esse método não retorna todos os elementos de uma coleção.This method does not return all the elements of a collection. Em vez disso, ele determina se todos os elementos de uma coleção satisfazem uma condição.Instead, it determines whether all the elements of a collection satisfy a condition.

A enumeração de source é interrompido assim que o resultado pode ser determinado.The enumeration of source is stopped as soon as the result can be determined.

Na sintaxe de expressão de consulta do Visual Basic, uma Aggregate Into All() cláusula se traduz em uma invocação de All.In Visual Basic query expression syntax, an Aggregate Into All() clause translates to an invocation of All.

Aplica-se a

Veja também