Andrew Zhu | Xhinker

Many people want to store WF4 persistence data in xml file rather than in Sql Server(express). So I extract the xml persistence store code from the sample "PurchaseProcess".
XmlWorkflowInstanceStore.zip (4.72 kb)
Before using this xml persistence store, you need to set up the data folder in App.config file:

<configuration>

  <appSettings>

    <add key="WF4DataFolderDirectory" value="c:\"/>

  </appSettings>

  …

Here is a using sample:
       Workflow1:     

    /// <summary>

    /// Start And Unload Instance

    /// </summary>

    static void StartAndUnloadInstance() {

        AutoResetEvent waitHandler = new AutoResetEvent(false);

        WorkflowApplication wfApp = new WorkflowApplication(new Workflow1());

        XmlWorkflowInstanceStore instanceStore =
                                  SetupXmlpersistenceStore(wfApp.Id);

        wfApp.InstanceStore = instanceStore;      

        ///persists application state and remove it from memory    
        wfApp.PersistableIdle = (e) => {                      

            return PersistableIdleAction.Unload;

        };

        wfApp.Unloaded = (e) => {

            Console.WriteLine("unload");

            waitHandler.Set();

        };

        Guid id = wfApp.Id;

        wfApp.Run();

        waitHandler.WaitOne();

        LoadAndCompleteInstance(id, instanceStore);

    }

    static void LoadAndCompleteInstance(Guid id,InstanceStore instanceStore) {

        AutoResetEvent waitHandler = new AutoResetEvent(false);

        Console.WriteLine("Press <enter> to load the persisted workflow");

        Console.ReadLine();

        WorkflowApplication wfApp = new WorkflowApplication(new Workflow1());

        wfApp.InstanceStore = instanceStore;

        wfApp.Completed = (workflowApplicationCompletedEventArgs) => {

            Console.WriteLine("\nWorkflowApplication has Completed in the {0} state.",       workflowApplicationCompletedEventArgs.CompletionState);

        };

        wfApp.Unloaded = (workflowApplicationEventArgs) => {

            Console.WriteLine("WorkflowApplication has Unloaded\n");

            waitHandler.Set();

        };

        wfApp.Load(id);

        wfApp.Run();
        waitHandler.WaitOne();

    }

    private static XmlWorkflowInstanceStore SetupXmlpersistenceStore(Guid workflowId) {

        XmlWorkflowInstanceStore instanceStore = new XmlWorkflowInstanceStore(workflowId);

        InstanceHandle handle = instanceStore.CreateInstanceHandle();

        InstanceView view=instanceStore.Execute(handle,
                                                new CreateWorkflowOwnerCommand(),
                                                TimeSpan.FromSeconds(5));

        handle.Free();

        instanceStore.DefaultInstanceOwner=view.InstanceOwner;

        return instanceStore;

    }

WF4