WorkflowQueuingService.Exists(IComparable) Method
Definition
Important
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Tests for the existence of the specified WorkflowQueue.
public:
bool Exists(IComparable ^ queueName);public bool Exists (IComparable queueName);member this.Exists : IComparable -> boolPublic Function Exists (queueName As IComparable) As BooleanParameters
- queueName
- IComparable
The name of the WorkflowQueue.
Returns
true if the WorkflowQueue exists; otherwise, false.
Exceptions
queueName is a null reference (Nothing in Visual Basic).
Examples
The following code example demonstrates a method, named CreateQueue, that initializes a WorkflowQueuingService object by calling the ActivityExecutionContext.GetService method. The code then uses the Exists method to determine if a WorkflowQueue with a specified name exists. If it does not exist, the code calls the CreateWorkflowQueue method; if it does the code calls the GetWorkflowQueue method.
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 WorkflowQueue CreateQueue(ActivityExecutionContext context)
{
Console.WriteLine("CreateQueue");
WorkflowQueuingService qService = context.GetService<WorkflowQueuingService>();
if (!qService.Exists(this.QueueName))
{
qService.CreateWorkflowQueue(this.QueueName, true);
}
return qService.GetWorkflowQueue(this.QueueName);
}
Private Function CreateQueue(ByVal context As ActivityExecutionContext) As WorkflowQueue
Console.WriteLine("CreateQueue")
Dim qService As WorkflowQueuingService = context.GetService(Of WorkflowQueuingService)()
If Not qService.Exists(Me.queueName) Then
qService.CreateWorkflowQueue(Me.queueName, True)
End If
Return qService.GetWorkflowQueue(Me.QueueName)
End Function
