BlockingCollection<T>.GetConsumingEnumerable Méthode

public:
 System::Collections::Generic::IEnumerable<T> ^ GetConsumingEnumerable(System::Threading::CancellationToken cancellationToken);

public System.Collections.Generic.IEnumerable<T> GetConsumingEnumerable(System.Threading.CancellationToken cancellationToken);

member this.GetConsumingEnumerable : System.Threading.CancellationToken -> seq<'T>

Public Function GetConsumingEnumerable (cancellationToken As CancellationToken) As IEnumerable(Of T)

Public Iterator Function GetConsumingEnumerable (cancellationToken As CancellationToken) As IEnumerable(Of T)

Paramètres

Retours

Qui IEnumerable<T> supprime et retourne des éléments de la collection.

Exceptions

Remarques

Cette méthode permet au code client de supprimer des éléments de la collection à l’aide d’une boucle foreach (For Each in Visual Basic), ou de Parallel.ForEach ou d’une requête PLINQ. L’énumérateur continuera de fournir des éléments (le cas échéant) jusqu’à IsCompleted ce que la valeur renvoie la valeur true, et si IsCompleted elle est false, les blocs de boucle jusqu’à ce qu’un élément soit disponible ou jusqu’à ce qu’il CancellationToken soit annulé.

Voir aussi

• Collections thread-safe
• Vue d’ensemble de BlockingCollection

public:
 System::Collections::Generic::IEnumerable<T> ^ GetConsumingEnumerable();

public System.Collections.Generic.IEnumerable<T> GetConsumingEnumerable();

member this.GetConsumingEnumerable : unit -> seq<'T>

Public Function GetConsumingEnumerable () As IEnumerable(Of T)

Retours

Qui IEnumerable<T> supprime et retourne des éléments de la collection.

Exceptions

Exemples

L’exemple suivant montre comment utiliser la GetConsumingEnumerable méthode :

class ConsumingEnumerableDemo
{
    // Demonstrates:
    //      BlockingCollection<T>.Add()
    //      BlockingCollection<T>.CompleteAdding()
    //      BlockingCollection<T>.GetConsumingEnumerable()
    public static async Task BC_GetConsumingEnumerable()
    {
        using (BlockingCollection<int> bc = new BlockingCollection<int>())
        {
            // Kick off a producer task
            var producerTask = Task.Run(async () =>
            {
                for (int i = 0; i < 10; i++)
                {
                    bc.Add(i);
                    Console.WriteLine($"Producing: {i}");

                    await Task.Delay(100); // sleep 100 ms between adds
                }

                // Need to do this to keep foreach below from hanging
                bc.CompleteAdding();
            });

            // Now consume the blocking collection with foreach.
            // Use bc.GetConsumingEnumerable() instead of just bc because the
            // former will block waiting for completion and the latter will
            // simply take a snapshot of the current state of the underlying collection.
            foreach (var item in bc.GetConsumingEnumerable())
            {
                Console.WriteLine($"Consuming: {item}");
            }
            await producerTask; // Allow task to complete cleanup
        }
    }
}

module ConsumingEnumerableDemo =
    // Demonstrates:
    //      BlockingCollection<T>.Add()
    //      BlockingCollection<T>.CompleteAdding()
    //      BlockingCollection<T>.GetConsumingEnumerable()
    let blockingCollectionGetConsumingEnumerable () =
        task {
            use bc = new BlockingCollection<int>()
            // Kick off a producer task
            let producerTask =
                task {
                    for i = 0 to 9 do
                        bc.Add i
                        printfn $"Producing: {i}"

                        do! Task.Delay 100 // sleep 100 ms between adds
                    // Need to do this to keep foreach below from hanging
                    bc.CompleteAdding()
                }

            // Now consume the blocking collection with foreach.
            // Use bc.GetConsumingEnumerable() instead of just bc because the
            // former will block waiting for completion and the latter will
            // simply take a snapshot of the current state of the underlying collection.
            for item in bc.GetConsumingEnumerable() do
                printfn $"Consuming: {item}"
            do! producerTask // Allow task to complete cleanup
        }

'Imports System.Threading.Tasks
'Imports System.Collections.Concurrent

' Demonstrates:
' BlockingCollection<T>.Add()
' BlockingCollection<T>.CompleteAdding()
' BlockingCollection<T>.GetConsumingEnumerable()

Class ConsumingEnumerableDemo
    Shared Sub BC_GetConsumingEnumerable()
        Using bc As New BlockingCollection(Of Integer)()

            ' Kick off a producer task
            Task.Factory.StartNew(
                Sub()
                    For i As Integer = 0 To 9
                        bc.Add(i)
                        ' sleep 100 ms between adds
                        Thread.Sleep(100)
                    Next

                    ' Need to do this to keep foreach below from not responding.
                    bc.CompleteAdding()
                End Sub)
            ' Now consume the blocking collection with foreach.
            ' Use bc.GetConsumingEnumerable() instead of just bc because the
            ' former will block waiting for completion and the latter will
            ' simply take a snapshot of the current state of the underlying collection.
            For Each item In bc.GetConsumingEnumerable()
                Console.WriteLine(item)
            Next
        End Using
    End Sub
End Class

Voir aussi

• Collections thread-safe
• Vue d’ensemble de BlockingCollection