workflow-foundation

Windows workflow type load exception

I am building a state machine with windows workflow, and I am trying to new up an object from another assembly in my solution. When I build the solution, I get a TypeLoadException from the StateActivityValidator (which runs after a successful build to see that all the required properties are set and such). The type I am trying to crea...

Avoid firing OnWorkflowItem changed for changes made by the workflow

I have a state machine workflow that responds to changes in a list item. The workflow also updates the list item; is there any way to avoid firing the OnWorkflowItem changed event when the changes were made by the workflow? ...

Windows Service vs. Windows Workflow Foundation?

I need something that runs in the background and go into my database and scan and update certain rows based on certain logic. I need this to run like every hour and my environment is Windows Server 2003, SqlServer 2005. Is WWF good for this purpose? Or should I create a Windows Service? And, what's difference between WWF and Windows Se...

Changing workflows in runtime

I have two workflowInstance instances, one created using the WorkflowRuntime.CreateWorkflow(Type) an another using WorkflowRuntime.CreateWorkflow(XamlReader). I then try to insert the former as a child activity of the first. I had this working on a little prototype but when I tried to incorporate it to my project it didn't work. It thr...

How can I get a list of possible transitions for a given role in a state machine workflow?

Hi On a given state machine workflow, how do we find out the possible transitions for a given role. In my scenario, only certain roles have the permission to perform certain activities. I have to get that list. The helper class StateMachineWorkflowInstance isn't helpful here as it just returns all the possible transitions, ignoring the ...

Workflow Foundation: using workflow tasks without SharePoint?

I've previously done WF workflows hosted by SharePoint sites. We currently have to develop a pretty complex workflow for a vanilla ASP.NET application that, alas, does not run in a SharePoint context. I've noticed that when I create a 'plain' WF workflow in VS2008, I don't have the CreateTask, onTaskChanged etc activities. I suppose thi...

What is a dependency property?

What is a dependency property in .Net (especially in WWF context). What is the difference from the regular property? ...

How to access public workflow properties while in host application code?

I have a workflow that has a public "State" property that returns a custom class storing data about the workflow (it changes during the execution of the workflow). What is the best pattern/practice to get the value of that property while in the code of the workflow host (ASP.NET app in this case) at any point? I looked into the CallExt...

Windows Workflow Delay Activity serialization errors

I have a state machine workflow hosted in SharePoint with a delay activity in one state. When the timer fires the delay activity, I get a serialization error: "Engine RunWorkflow: System.Runtime.Serialization.SerializationException: Cannot get the member 'SendEmail_MethodInvoking'". The method this error references is not in the same s...

Sql Workflow Persistence Service does not save workflow state

Hallo everybody, I'm dealing with a pretty strange situation here. I have developed a State Machine Workflow and it worked just fine until today. Now, the Sql Workflow Persistence Service does not save the workflow state. There is no any exception, just it does not save the state. The flow is going normally to the Event Driven activity ...

Using Windows Workflow in ASP.NET AJAX application

I'm using Windows Workflow as part of a class library in an ASP.NET application. I've read all the suggestions about setting up WWF in ASP.NET and using a ManualWorkflowSchedulerservice, however, I'm not sure if that makes sense for my app. My workflows are all sequential, no persistance; they're fire and forget. A client makes a reques...

Binding parameters to Windows Workflow instance & ignoring unused ones

I have a bunch of named value parameters in a Dictionary<string, object>, which I want to pass into different workflows. The catch is that each workflow will only need a subset of the properties in the dictionary, and I don't know beforehand which workflow needs which properties. The problem is that when I call WorkflowRuntime.CreateWo...

What is the upper limit of WorkflowInstances that I may have instantiated at one time?

Is there an upper limit on the number of instances of WorkflowInstance I may have running at one time? I am using .Net 3.5 and C# (not that the language should make a difference.) Please note that I am not suggesting that it is a good design to many running at once, I am simply curious about the upper limit, if one exists. ...

Hitting breakpoints in Workflow Foundation (WF) designers

Hi folks, Is it true that you can't hit breakpoints in VS.NET 2008 workflow designer for workflows stored in a library, when invoked externally? I've got a Sequential Workflow Library project and a console app project in the same solution. I call the workflow from the app with code such as this (VB.NET): Dim wr As WorkflowRuntime =...

How to architect this ASP.NET n-tier solution?

I have a problem trying to layout my VS solution and I would like some suggestions, please. Currently, my solution layout looks like the following project:- Foo.Models Foo.Repositories Foo.Services Foo.Web (an ASP.NET MVC application) my website (Foo.Web) calls various methods on the Foo.Services namespace. The idea here is that the ...

Workflow Foundation ExternalDataExchange messages queued and transactional?

I've been working with some ExternalDataExchange - based communication in WF recently. My understanding is that when working with a long-running (in this case, a State Machine) workflows, communication is queued, durable, and transactional. I'm using SQL Persistence and a EventArgs that is marked as "WaitForIdle = true". I would assum...

Can you recommend any resources for learning WorkFlow in 3 days?

I'm replacing another developer in the final phase of an ASP.NET project using workflows. As I understand it, most of the project is complete but the workflows parts are still work in progress. This was a surprise assignment and now I have a long weekend to prepare. Can you recommend any resources to get me up to speed? I can learn on ...

Is it better to have one big workflow or several smaller specific ones?

I need to build an app that gets files from a server and moves to another server. It was suggested that I look into using Windows Workflow Foundation (WF). I started to build the workflow but it is getting messy and I'm not sure I'm doing it the best way possible. Here is the basic worklow activities: Get a list of sources Dete...

WPF or workflow?

Hey People, I have a question and hopefully you can steer me in the right direction. I'm working on an application that needs some form of decision tree/work flow for lack of a better term. I'll describe it below for some clarity. I have a request form that users will fill out on a web page. At the beginning of the form is a 'Referral...

capturing webform event for workflow on asp.net site

The basic idea is that I have a website and a workflow. I need to capture button clicks from aspx pages in my workflow. I have a solution with a worflow project and a website project, and the web.config and global.asax have been set up to work with WF. Persistence services are also set up. I have created a StateMachine workflow. There...