Using ASP.NET with windows workflow foundation - asp.net

Question

I try to build up a asp.net web application with windows workflow foundation.
I have found some useful sites like:
http://msdn.microsoft.com/en-us/library/bb628441%28v=vs.90%29.aspx
http://msdn.microsoft.com/en-us/library/bb675262%28v=vs.90%29.aspx
The workflow is an Activity
<Activity mc:Ignorable="sap" x:Class="ApproachWithWorkflows.WriteLineActivity" sap:VirtualizedContainerService.HintSize="654,676" mva:VisualBasic.Settings="Assembly references and imported namespaces for internal implementation" xmlns="http://schemas.microsoft.com/netfx/2009/xaml/activities" xmlns:av="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:mv="clr-namespace:Microsoft.VisualBasic;assembly=System" xmlns:mva="clr-namespace:Microsoft.VisualBasic.Activities;assembly=System.Activities" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:s1="clr-namespace:System;assembly=System" xmlns:s2="clr-namespace:System;assembly=System.Xml" xmlns:s3="clr-namespace:System;assembly=System.Core" xmlns:sad="clr-namespace:System.Activities.Debugger;assembly=System.Activities" xmlns:sap="http://schemas.microsoft.com/netfx/2009/xaml/activities/presentation" xmlns:scg="clr-namespace:System.Collections.Generic;assembly=System" xmlns:scg1="clr-namespace:System.Collections.Generic;assembly=System.ServiceModel" xmlns:scg2="clr-namespace:System.Collections.Generic;assembly=System.Core" xmlns:scg3="clr-namespace:System.Collections.Generic;assembly=mscorlib" xmlns:sd="clr-namespace:System.Data;assembly=System.Data" xmlns:sl="clr-namespace:System.Linq;assembly=System.Core" xmlns:st="clr-namespace:System.Text;assembly=mscorlib" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Flowchart sad:XamlDebuggerXmlReader.FileName="C:\Documents and Settings\hauke\Desktop\Uni\Masterarbeit SVN SE\Software\Workflowansatz\ApproachWithWorkflows\ApproachWithWorkflows\WriteLineActivity.xaml" sap:VirtualizedContainerService.HintSize="614,636">
<sap:WorkflowViewStateService.ViewState>
<scg3:Dictionary x:TypeArguments="x:String, x:Object">
<x:Boolean x:Key="IsExpanded">False</x:Boolean>
<av:Point x:Key="ShapeLocation">270,2.5</av:Point>
<av:Size x:Key="ShapeSize">60,75</av:Size>
<av:PointCollection x:Key="ConnectorLocation">300,77.5 300,107.5 295.5,107.5 295.5,129</av:PointCollection>
</scg3:Dictionary>
</sap:WorkflowViewStateService.ViewState>
<Flowchart.StartNode>
<x:Reference>__ReferenceID0</x:Reference>
</Flowchart.StartNode>
<FlowStep x:Name="__ReferenceID0">
<sap:WorkflowViewStateService.ViewState>
<scg3:Dictionary x:TypeArguments="x:String, x:Object">
<av:Point x:Key="ShapeLocation">190,129</av:Point>
<av:Size x:Key="ShapeSize">211,59</av:Size>
</scg3:Dictionary>
</sap:WorkflowViewStateService.ViewState>
<WriteLine sap:VirtualizedContainerService.HintSize="211,59" Text="worked.." />
</FlowStep>
I created an asp.net project with a simple button:
<asp:Button Text="Purchase" ID="Label1" runat="server" OnClick="btnClick" />
In the code behind, I try to call the workflow (and initialized the WorkflowRuntime in the global.asax by Application_Start):
WorkflowRuntime workflowRuntime = Application["WorkflowRuntime"] as WorkflowRuntime;
ManualWorkflowSchedulerService manualScheduler =
workflowRuntime.GetService(typeof(ManualWorkflowSchedulerService))
as ManualWorkflowSchedulerService;
WorkflowInstance instance = workflowRuntime.CreateWorkflow(
typeof(ApproachWithWorkflows.WriteLineActivity));
instance.Start();
manualScheduler.RunWorkflow(instance.InstanceId);
When I now execute the application and press the button, I get an error like "The input workflow type must be an Activity.\r\nParameter name: workflowType" at CreateWorkflow.
But the Activity is an Activity! What am I doing wrong?

Answer 1

It looks like you're using WF 3.5 runtime classes to execute a WF 4.0 activity. Take a look at WorkflowInvoker or WorkflowApplication.