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WF, WCF, and AppFabric notes

Tracking an Expression activity in Windows Workflow Foundation

Since the nodes in a Flowchart do not derive from Activity, they do not have the tracking...

Date: 08/09/2011

Making an activity's display name readonly in the Workflow 4 designer

To make an activity's display name readonly, it isn't enough to use the ReadOnlyAttribute on the...

Date: 05/16/2011

Constraining what activities can be dropped on a custom activity designer in Workflow 4

When designing a custom activity that can be used as a container for other activities, you may want...

Date: 05/09/2011

Programmatically calling validation in a rehosted Workflow 4 designer

The workflow designer has a rich programming model that supports communication with the host. A...

Date: 04/27/2011

WF 4 hosting options: IIS, AppFabric, and Windows Service

Most of the Windows Workflow Foundation samples use workflows that are hosted in a console...

Date: 04/18/2011

HttpContext.Current returning null when using NetTcpBinding in WCF4

When using NetTcpBinding, not all of the features of WCF are available, particularly those using...

Date: 04/06/2011

Error message in WF4: "Error: The values provided for the root activity's arguments did not satisfy the root activity's requirements"

When loading an activity assembly using Assembly.LoadFrom, you may see the following error: "Error:...

Date: 04/06/2011

Workflow Designer: What properties appear in the Properties pane when activities are multi-selected?

When multiple activities are selected in the Workflow Designer surface with ctrl+click, it's not...

Date: 03/17/2011

Validation error message: "An error occurred while attempting to extract the target object of type 'System.Activites.InArgument' from the method call expression .Get"

When using the (non-Generic) version of InArgument, you may see the following error message during...

Date: 03/16/2011

Cancelling an AsyncCodeActivity

Even when AsyncCodeActivity.Cancel is called, the activity will still execute the EndExecute method,...

Date: 03/16/2011

WF 4 SqlWorkflowInstanceStore: Supported SQL Server versions

The SqlWorkflowInstanceStore is an out-of-box instance store implementation in Workflow 4 that uses...

Date: 03/11/2011

Using a SymbolResolver to access host environment information

To access environment information from within an activity, you'll need to use the...

Date: 03/10/2011

WF 3.5 Persistence and Tracking: Two databases or one?

This refers to the previous version of Workflow, but it came up in a recent discussion, so I thought...

Date: 03/03/2011

Error message: "The argument of type '' cannot be used. Make sure that it is declared on an activity."

The following error might occur when an activity executes: The argument of type '<type>'...

Date: 02/23/2011

Piping the result of Activity to another activity as an input argument

Expression activities (that is, activities that return a value, inheriting from Activity<T>,...

Date: 02/17/2011

Rules and rulesets in Workflow 4

It's always difficult to find the lack of something in a search engine. Rulesets, a feature of...

Date: 02/15/2011