WorkflowInstance.GetWorkflowQueueData 方法

定義

命名空間:

System.Workflow.Runtime

組件:

System.Workflow.Runtime.dll

取得 WorkflowQueueInfo 物件的集合，其中包含此工作流程執行個體關聯的工作流程佇列之暫止項目 (Pending Item) 與訂閱的活動。

public:
 System::Collections::ObjectModel::ReadOnlyCollection<System::Workflow::Runtime::WorkflowQueueInfo ^> ^ GetWorkflowQueueData();

public System.Collections.ObjectModel.ReadOnlyCollection<System.Workflow.Runtime.WorkflowQueueInfo> GetWorkflowQueueData ();

member this.GetWorkflowQueueData : unit -> System.Collections.ObjectModel.ReadOnlyCollection<System.Workflow.Runtime.WorkflowQueueInfo>

Public Function GetWorkflowQueueData () As ReadOnlyCollection(Of WorkflowQueueInfo)

傳回

ReadOnlyCollection<WorkflowQueueInfo>

ReadOnlyCollection<T> 物件的 WorkflowQueueInfo。

例外狀況

InvalidOperationException

工作流程執行階段引擎不在執行中。

範例

下列程式碼範例將示範如何使用 GetWorkflowQueueData 方法，以取得與 WorkflowInstance 物件關聯的所有工作流程佇列的狀態資訊。 當 WorkflowIdled 事件發生時，會呼叫此範例中定義的 OnWorkflowIdled 方法。 它會使用 WorkflowInstance 屬性判斷閒置的工作流程，然後呼叫 GetWorkflowQueueData 方法取得工作流程執行個體之佇列項目的集合。 此程式碼會在集合上反覆查看，以判斷是哪個活動正在等候閒置工作流程的事件。 然後，它會使用 EnqueueItem 方法以及事件佇列項目的名稱，將例外狀況傳送到工作流程佇列中。

這個程式碼範例是 Program.cs 檔案中＜取消工作流程 SDK＞範例的一部分。 如需詳細資訊，請參閱 取消工作流程。

static void OnWorkflowIdled(object sender, WorkflowEventArgs e)
{
    WorkflowInstance workflow = e.WorkflowInstance;

    Console.WriteLine("\n...waiting for 3 seconds... \n");
    Thread.Sleep(3000);

    // what activity is blocking the workflow
    ReadOnlyCollection<WorkflowQueueInfo> wqi = workflow.GetWorkflowQueueData();
    foreach (WorkflowQueueInfo q in wqi)
    {
        EventQueueName eq = q.QueueName as EventQueueName;
        if (eq != null)
        {
            // get activity that is waiting for event
            ReadOnlyCollection<string> blockedActivity = q.SubscribedActivityNames;
            Console.WriteLine("Host: Workflow is blocked on " + blockedActivity[0]);

            // this event is never going to arrive eg. employee left the company
            // lets send an exception to this queue
            // it will either be handled by exception handler that was modeled in workflow
            // or the runtime will unwind running compensation handlers and exit the workflow
            Console.WriteLine("Host: This event is not going to arrive");
            Console.WriteLine("Host: Cancel workflow with unhandled exception");
            workflow.EnqueueItem(q.QueueName, new Exception("ExitWorkflowException"), null, null);
        }
    }
}

Shared Sub OnWorkflowIdled(ByVal sender As Object, ByVal e As WorkflowEventArgs)
    Dim workflow As WorkflowInstance = e.WorkflowInstance

    Console.WriteLine(vbCrLf + "...waiting for 3 seconds... " + vbCrLf)
    Thread.Sleep(3000)

    ' what activity is blocking the workflow
    Dim wqi As ReadOnlyCollection(Of WorkflowQueueInfo) = workflow.GetWorkflowQueueData()
    For Each q As WorkflowQueueInfo In wqi

        Dim eq As EventQueueName = TryCast(q.QueueName, EventQueueName)

        If eq IsNot Nothing Then
            ' get activity that is waiting for event
            Dim blockedActivity As ReadOnlyCollection(Of String) = q.SubscribedActivityNames
            Console.WriteLine("Host: Workflow is blocked on " + blockedActivity(0))

            ' this event is never going to arrive eg. employee left the company
            ' lets send an exception to this queue
            ' it will either be handled by exception handler that was modeled in workflow
            ' or the runtime will unwind running compensation handlers and exit the workflow
            Console.WriteLine("Host: This event is not going to arrive")
            Console.WriteLine("Host: Cancel workflow with unhandled exception")
            workflow.EnqueueItem(q.QueueName, New Exception("ExitWorkflowException"), Nothing, Nothing)
        End If
    Next
End Sub

備註

GetWorkflowQueueData 會傳回 WorkflowQueueInfo 物件的集合，每一個物件都包含與此工作流程執行個體關聯的其中一個工作流程佇列狀態的資訊。 WorkflowQueueInfo.Items 包含 WorkflowQueue 的暫止項目，而 WorkflowQueueInfo.SubscribedActivityNames 則包含在 WorkflowQueue 上傳遞項目的訂閱活動清單。

另請參閱

• 取消工作流程