The Activity Designer

Issuing, Handling, and Intercepting Commands in a WF4 Rehosted Designer application. Background on Commands in WPF I thought I understood Commands, but when I found myself having difficulties explaining things to a customer last week I realized...

One of our internal customers pinged me with a quick question today. He asked whether it is possible to set a default type argument for T if you have an activity of GenericType, say DataCollectorActivity<T>. I might have said this in passing by...

I don’t remember anyone ever actually asking me this, but I found myself wondering the question today while rustling up a quick rehosting app. Foreach<> activity lets you change the TypeArgument dynamically via the property grid. But FlowSwitch<>...

[Or: Rant - Code-Reviewing Random Code on the Internet.] I’m sure I’ve stumbled upon this post before once, and I hit it again today. I think it’s a little unfortunate this appears so high up in the results, as the post has a bunch...

or: best practices registering Workflow Activity Designers Getting your first custom Activity Designer to show up is not hard. There are plenty of samples to find. However, something mostly under-explained in such samples is that the way you get started...

Here’s a workflow designer FAQ finally getting the attention it deserves, and helping show off how to do custom property editing in designer. “How do I show an InArgument<bool>/<enum> in the property grid as a checkbox/combobox?”   [Aside...

Briefly diverging from regular posts: here’s something really fun. As far as I know, prior to 4.0, .Net has had, two built in ways to do weak object references. 1) WeakHandle 2) GCHandle, which is what WeakHandle uses under the covers. If you have ever...

[Edit – I had to cut the pictures, they got broken by software update issues.] With two forum posts in two days vaguely related to Literal<T>, suddenly the Literal<T> problem seems interesting again. Shortly prior to the release of Visual...

Not to forget the interests of regular readers, you can get some of the latest WF news from Ron Jacob’s Windows Workflow Foundation Futures PDC talk. Updating with the direct link: http://player.microsoftpdc.com/Session/3b87c17b-a218-40d3-984f-78a012331dee...

It might be the first time I someone contacted me to about a blog they wrote about custom WF activities. Of course I was chuffed that they thought I might be interested. The articles really were interesting to me so I’m doubly happy to link them: http...

Only 8 more days to go ‘til October 28! PDC is sold out, but if you’re not attending in person, 1) keynotes and sessions are going to be streaming live 2) there might be a local event in your area to attend. Locations are listed here . For all 6 continents...

Part 1 is here . At the end of Part 1, I’ve decided it’s time to try this COM Message Filter thing out. Implementing the IMessageFilter interface and registering the message filter turns out to be not hard at all, because really, in our case the message...

(Note: The previous article on customizing commands for a rehosted Workflow Designer is here . It is probably better to go that way if you are only shipping designers in rehosted scenarios.) Due to another forum thread on customizing command behavior...

[Deviation from WF posting again.] Sometimes you learn enough about something just well enough to write some code that is useful. A month later, you wake and say… ‘but I still don’t really feel like I know what is going on.’ Today is such a day to clear...

MDBG is, briefly, a sample managed library for writing debuggers which uses COM interop and the CLR hosting debugger APIs ( ICorDebug interface etc.). As far as I can find, the most recent version of the MDB sample is still the .net 2.0 version, which...

For background: in ContextBoundObject #1 – Creating Contexts we started reverse engineering SynchronizationAttribute to figure out how to create Contexts for ContextBoundObjects . Creating a Context was fairly easy and… on it’s own useless. Yes, a context...

Link - “TFS and WF4- The diff noise problem” - I just saw this post from Rory which looked useful for anyone using WinMerge (it’s free). Of course not everyone uses the same diff tools. I’m rather partial to  SourceGear|DiffMerge (also free), which...

[Update 08/03/11: fixed a few horrible proofreading issues which slipped past my nonexistant editor] Today we’re going to explore some internal workings of ModelItem - or really its concrete subclass ModelItemImpl. ModelItemImpl is an internal...

I got lost in some circle of WPF hell this afternoon. Eventually I started wondering if using ICollectionViewFactory to instantiate a collection view would be the cure to all my problems. However, I found myself banging my head against brick walls just...

(Category: Rambling) Sometimes it’s funny how the same simple problem comes up over and over again, and people immediately solve it over and over again. Of course usually I only notice it when I am one of those people. Some time back I found myself writing...

For one of my little projects at work, I’ve been creating a utility which will run as a child process which is just hosted as a console application. It prints a lot of output to console, and it would be kinda useful to be able to capture all the output...

Yes, we’re finally shipping Visual Studio 10! Listening to the launch live .

I may need to update some earlier blog posts, but in the meantime you can find the latest WF4 and WCF4 samples (with sample bugs fixed) to download here . (Also - WCF samples readme doc is here and WF samples readme doc is here .)

Something that I had as a blog post was almost useful to someone. Almost, except for all the rough edges. So here is a second release of the post ‘An Activity Designer for InvokeAction’......

There are a few things I feel like I should be able to do inside of a NativeActivity, but can’t - easily. Luckily, there is a way. #1 – Resuming bookmarks – where is my workflow Instance? You can resume a bookmark from within NativeActivity.Execute()...