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

Definición

Determina si todos los elementos de una secuencia satisfacen una condición.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

Parámetros de tipo

TSource

Tipo de los elementos de source.The type of the elements of source.

Parámetros

source
IEnumerable<TSource>

IEnumerable<T> que contiene los elementos a los que se va a aplicar el predicado.An IEnumerable<T> that contains the elements to apply the predicate to.

predicate
Func<TSource,Boolean>

Función para probar cada elemento de una condición.A function to test each element for a condition.

Devoluciones

true si todos los elementos de la secuencia de origen pasan la prueba del predicado especificado o si la secuencia está vacía; de lo contrario, false.true if every element of the source sequence passes the test in the specified predicate, or if the sequence is empty; otherwise, false.

Excepciones

source o predicate es null.source or predicate is null.

Ejemplos

En el ejemplo de código siguiente se muestra cómo usar All para determinar si todos los elementos de una secuencia satisfacen una condición.The following code example demonstrates how to use All to determine whether all the elements in a sequence satisfy a condition. Variable allStartWithB es true si todos los nombres de mascota empieza por "B" o si el pets matriz está vacía.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'.

El valor booleano que el All devuelve del método se utiliza normalmente en el predicado de un where cláusula (Where cláusula en Visual Basic) o una llamada directa a la 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. En el ejemplo siguiente se muestra este uso de la 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

Comentarios

Nota

Este método no devuelve todos los elementos de una colección.This method does not return all the elements of a collection. En su lugar, determina si todos los elementos de una colección cumplen una condición.Instead, it determines whether all the elements of a collection satisfy a condition.

La enumeración de source se detiene tan pronto como se puede determinar el resultado.The enumeration of source is stopped as soon as the result can be determined.

En la sintaxis de expresión de consulta de Visual Basic, un Aggregate Into All() cláusula se convierte en una invocación de All.In Visual Basic query expression syntax, an Aggregate Into All() clause translates to an invocation of All.

Se aplica a

Consulte también: