WorkflowQueue.Count Property

Definition

Namespace:

System.Workflow.Runtime

Assembly:

System.Workflow.Runtime.dll

Gets the number of items contained in the WorkflowQueue.

public:
 property int Count { int get(); };

public int Count { get; }

member this.Count : int

Public ReadOnly Property Count As Integer

Property Value

Int32

The number of items in the workflow queue.

Examples

The following code example demonstrates how you can create a WorkflowQueue by calling the WorkflowQueuingService.GetWorkflowQueue method. It also uses the Count property to determine whether any messages exist in the current queue. Finally, the code uses the Dequeue method to remove and return the first object in the queue.

This code example is part of the File Watcher Activity SDK Sample from the FileSystemEvent.cs file. For more information, see File System Watcher Activity.

private bool ProcessQueueItem(ActivityExecutionContext context)
{
    WorkflowQueuingService qService = context.GetService<WorkflowQueuingService>();
    if (!qService.Exists(this.QueueName))
    {
        return false;
    }

    WorkflowQueue queue = qService.GetWorkflowQueue(this.QueueName);

    // If the queue has messages, then process the first one
    if (queue.Count == 0)
    {
        return false;
    }

    FileWatcherEventArgs e = (FileWatcherEventArgs)queue.Dequeue();

    // Raise the FileSystemEvent
    base.RaiseGenericEvent<FileWatcherEventArgs>(FileSystemEvent.FileWatcherEventHandlerEvent, this, e);

    DoUnsubscribe(context, this);
    DeleteQueue(context);
    return true;
}

Private Function ProcessQueueItem(ByVal context As ActivityExecutionContext) As Boolean

    Dim qService As WorkflowQueuingService = context.GetService(Of WorkflowQueuingService)()

    If Not qService.Exists(Me.QueueName) Then
        Return False
    End If

    Dim Queue As WorkflowQueue = qService.GetWorkflowQueue(Me.QueueName)

    ' If the queue has messages, then process the first one
    If Queue.Count = 0 Then
        Return False
    End If

    Dim e As FileWatcherEventArgs = CType(Queue.Dequeue(), FileWatcherEventArgs)

    ' Raise the FileSystemEvent
    MyBase.RaiseGenericEvent(Of FileWatcherEventArgs)(FileSystemEvent.FileWatcherEventHandlerEvent, Me, e)
    DoUnsubscribe(context, Me)
    DeleteQueue(context)
    Return True
End Function

See also

• File System Watcher Activity