Assembly: System.Workflow.Runtime (in system.workflow.runtime.dll)
There is no persistence service registered with the workflow runtime engine.
Unload is synchronous; that is, it returns after completing any action that it performs. If the workflow instance is not idle, then the runtime waits until the instance can be interrupted. An instance can only be interrupted after the currently scheduled work item completes- this is typically when the currently running Activity returns from its Execute method. However, if the instance is executing a TransactionScopeActivity, then the transaction scope must complete execution before the instance can be interrupted. Unload then uses the persistence service to remove the workflow instance from memory and persists it to a data store. If there is no persistence service registered with the WorkflowRuntime, Unload throws an InvalidOperationException. If the workflow instance is successfully persisted, the runtime raises the WorkflowUnloaded event.
The host can use Unload to reclaim system resources from an idle workflow.
The following example demonstrates calling Unload on a WorkflowInstance object.
// Create a WorkflowRuntime object WorkflowRuntime workflowRuntime = new WorkflowRuntime(); // Create a new instance of the out-of-box SqlWorkflowPersistenceService SqlWorkflowPersistenceService persistenceService = new SqlWorkflowPersistenceService( "Initial Catalog=SqlPersistenceService;Data Source=localhost;Integrated Security=SSPI;"); // Add the service to the runtime workflowRuntime.AddService(persistenceService); // Create a WorkflowInstance object WorkflowInstance workflowInstance = workflowRuntime.CreateWorkflow(typeof(IdleWorkflow)); // Start the workflow instance workflowInstance.Start(); //Unload the instance workflowInstance.Unload();
Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter EditionThe Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.