Enumerable.LongCount Enumerable.LongCount Enumerable.LongCount Enumerable.LongCount Method

Definição

Retorna um Int64 que representa o número de elementos em uma sequência.Returns an Int64 that represents the number of elements in a sequence.

Sobrecargas

LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

Retorna um Int64 que representa quantos elementos na sequência atendem a uma condição.Returns an Int64 that represents how many elements in a sequence satisfy a condition.

LongCount<TSource>(IEnumerable<TSource>) LongCount<TSource>(IEnumerable<TSource>) LongCount<TSource>(IEnumerable<TSource>) LongCount<TSource>(IEnumerable<TSource>)

Retorna um Int64 que representa o número total de elementos em uma sequência.Returns an Int64 that represents the total number of elements in a sequence.

LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

Retorna um Int64 que representa quantos elementos na sequência atendem a uma condição.Returns an Int64 that represents how many elements in a sequence satisfy a condition.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static long LongCount(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, bool> ^ predicate);
public static long LongCount<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,bool> predicate);
static member LongCount : seq<'Source> * Func<'Source, bool> -> int64
<Extension()>
Public Function LongCount(Of TSource) (source As IEnumerable(Of TSource), predicate As Func(Of TSource, Boolean)) As Long

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 a serem contados.An IEnumerable<T> that contains the elements to be counted.

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

Um número que representa quantos elementos na sequência atendem à condição na função de predicado.A number that represents how many elements in the sequence satisfy the condition in the predicate function.

Exceções

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

O número de elementos correspondentes excede MaxValue.The number of matching elements exceeds MaxValue.

Exemplos

O exemplo de código a seguir demonstra como LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) usar o para contar os elementos em uma matriz que atendem a uma condição.The following code example demonstrates how to use LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) to count the elements in an array that satisfy a condition.

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

public static void LongCountEx2()
{
    Pet[] pets = { new Pet { Name="Barley", Age=8 },
                   new Pet { Name="Boots", Age=4 },
                   new Pet { Name="Whiskers", Age=1 } };

    const int Age = 3;

    long count = pets.LongCount(pet => pet.Age > Age);

    Console.WriteLine("There are {0} animals over age {1}.", count, Age);
}

/*
 This code produces the following output:

 There are 2 animals over age 3.
*/
Structure Pet
    Public Name As String
    Public Age As Integer
End Structure

Sub LongCountEx2()
    ' Create a list of Pet objects.
    Dim pets As New List(Of Pet)(New Pet() _
                 {New Pet With {.Name = "Barley", .Age = 8},
                  New Pet With {.Name = "Boots", .Age = 4},
                  New Pet With {.Name = "Whiskers", .Age = 1}})

    ' Determine the number of elements in the list
    ' where the pet's age is greater than a constant value (3).
    Const Age As Integer = 3
    Dim count As Long =
pets.LongCount(Function(pet) pet.Age > Age)

    ' Display the result.
    MsgBox("There are " & count & " animals over age " & Age)
End Sub

' This code produces the following output:
'
' There are 2 animals over age 3

Comentários

Use esse método em vez Count de quando você espera que o resultado seja maior MaxValueque.Use this method rather than Count when you expect the result to be greater than MaxValue.

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

Veja também

LongCount<TSource>(IEnumerable<TSource>) LongCount<TSource>(IEnumerable<TSource>) LongCount<TSource>(IEnumerable<TSource>) LongCount<TSource>(IEnumerable<TSource>)

Retorna um Int64 que representa o número total de elementos em uma sequência.Returns an Int64 that represents the total number of elements in a sequence.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static long LongCount(System::Collections::Generic::IEnumerable<TSource> ^ source);
public static long LongCount<TSource> (this System.Collections.Generic.IEnumerable<TSource> source);
static member LongCount : seq<'Source> -> int64
<Extension()>
Public Function LongCount(Of TSource) (source As IEnumerable(Of TSource)) As Long

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 a serem contados.An IEnumerable<T> that contains the elements to be counted.

Retornos

O número de elementos na sequência de origem.The number of elements in the source sequence.

Exceções

O número de elementos excede MaxValue.The number of elements exceeds MaxValue.

Exemplos

O exemplo de código a seguir demonstra como LongCount<TSource>(IEnumerable<TSource>) usar para contar os elementos em uma matriz.The following code example demonstrates how to use LongCount<TSource>(IEnumerable<TSource>) to count the elements in an array.

string[] fruits = { "apple", "banana", "mango", 
                      "orange", "passionfruit", "grape" };

long count = fruits.LongCount();

Console.WriteLine("There are {0} fruits in the collection.", count);

/*
 This code produces the following output:

 There are 6 fruits in the collection.
*/
' Create an array of strings.
Dim fruits() As String =
{"apple", "banana", "mango", "orange", "passionfruit", "grape"}

' Get the number of items in the array.
Dim count As Long = fruits.LongCount()

' Display the result.
MsgBox("There are " & count & " fruits in the collection.")

' This code produces the following output:
'
' There are 6 fruits in the collection.

Comentários

Use esse método em vez Count de quando você espera que o resultado seja maior MaxValueque.Use this method rather than Count when you expect the result to be greater than MaxValue.

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

Veja também

Aplica-se a