I've arrived in Orlando and am looking forward to giving my sessions tomorrow and Wed in the Visual Studio connections track. I'll be presenting the following sessions:

- WPF in Windows Forms and vice versa: This talk will cover the interop story for containing WPF controls in Windows Forms applications and Windows Forms controls in WPF applications. Quite a compelling story for migrating incrementally to WPF, but not without its share of pain points.

- Real World .NET 3.0 Smart Client Deployment: This is a modification of my Real World ClickOnce talk, covering the key aspects of ClickOnce deployment but with a slant towards the special considerations introduced by .NET 3.0 for security and WPF deployment models.

- Encapsulate Business Processes in Custom WF Activities: This talk covers how to create custom simple and composite WF activities and all the many things you need to take into consideration to make a robust, reusable activity.

This year the conferences is at the World Center Marriott, a change from the Hyatt Grand Regency of the last few years. Verdict is still out whether this is an improvement...

Another great conference complete. Around 5000 showed up and we had great feedback from the crowd that it was a good show. If you haven't been to connections before, you really should check it out.

I gave three talks this week. You can get the slides and demos for each below.

Real World ClickOnce:  Slides   Demos
Workflow Driven Windows Applications:  Slides   Demos
Implement a Data Layer with the VS 2005 DataSet Designer:  Slides   Demos

I presented four sessions at DevConnections last week and have been a little remiss on getting the slides and demos posted, but here they are:

Secure ClickOnce Deployments:  Slides   Demos

Connecting Smart Clients with WCF: Slides   Demos

Drive Application Behavior with User and Application Settings:  Slides   Demos

Build a Data Access Layer with Enterprise Library Data Access Block:  Slides  Demos

I gave two WCF (Indigo) talks at DevConnections today:

Build Event Driven Applications with Indigo:   Slides   Demos

Connecting Smart Client Applications with Indigo:  Slides   Demos

In the Event Driven Applications session I cover creating list based subscription services with direct callback services in the clients, using duplex channels to set up callbacks, and a Pub-Sub implementation that gives loosely coupled events that I will have more information on here in the near future.

In the smart client session, I covered client concerns with respect to channel selection, asynchronous calls, sessions, transactions, callbacks, security, and peer-to-peer.

Good time!

I just got finished doing my first talk here at DevConnections in Vegas and I think it went pretty well. Great crowd, good questions, fun topic.

You can grab the slides and demos here: Slides   Demos

The talk highlighted how to define custom objects and collections to make them suitable for data binding, mostly for Windows Forms, but some of it is applicable to ASP.NET as well.

The key takeaways from the talk are:

• Implement INotifyPropertyChanged on any business entitity type you define that you expect to use in data binding scenarios. This interface defines a contract for the objects to raise PropertyChanged events whenever a property is set on the object. It allows containing collections or bound controls to be notified when the contents of the data object change, which helps with keeping controls synchronized in a form.
• Use BindingList<T> to create strongly typed collections of objects that support rich data binding. It provides full implementation of IList, ICollection, IEnumerable and their generic strongly typed counterparts for whatever type parameter you provide, and it provides a partial implementation of the IBindingList interface. The part that it implements is firing ListChanged events when items are added or removed from the collection. It also looks at the objects type that you provide as a type parameter, and if it implements INotifyPropertyChanged, the collection will subscribe to the PropertyChanged event on each object and raise ListChanged events with a change type of PropertyChanged whenever the contents of an object in the collection change. These features make BindingList<T> collections work seamlessly with data binding to multiple controls and keeps the controls all in sync.
• Use my BindingListView<T> class (in the demos and in my book) to get a generic container that supports sorting (both IBindingList based single property sorts and IBindingListView multi-property sorts), searching, and filtering.

If you were there at the end and saw the on-the-fly demo where I didn't see the saving behavior that I thought I had just implemented, I tracked down the problem. the changes were actually being saved. It was just the way I hooked up the data binding I wasn't seeing those changes.

In the demo, I used the data sources window to generate a Details view (control collection) bound to a collection of Album data. I changed one of the controls in the collection which was bound to a GenreID property on the Album objects to a ComboBox. I then used the Data Sources window to add data binidng to a Genre object collection to populate the list of Genres in the combo box. This sets up the ComboBox to have its contents determined by the Genre collection, but its SelectedValue property is bound to the GenreID property on the current item in the Album collection - generally exactly what you want to be able to edit a property on one object collection item through a lookup list of values in another collection of objects. The problem was that after I selected a new value in the combo box and saved the changes, then restarted the app, I wasn't seeing the modified value set for the Album I was viewing in the other controls.

It turns out the problem was just the order that I did the initial binding of the control collection and the combobox BindingSources. In the form load I had added the following two lines of code to bind the control collection and the combo box binding sources:

albumBindingSource.DataSource = Album.GetAlbums();
genreBindingSource.DataSource = Genre.GetGenres();

The problem is that when you set the DataSource, that is when it intializes the bound controls. So I was initializing the data bindings for all of the controls based on the album data, then intializing the combo box of Genres with a new set of data. That set the SelectedIndex of the ComboBox back to zero, so I wasn't seeing the actual value of the Genre for the current Album, I was just seeing the first Genre value in the Genre collection. The fix is simply to do the initial binding in the reverse order:

Enjoy!

I'm catching a flight early tomorrow morning to Vegas for VS Connections and am really looking forward to it. VS Connections in particular, and DevConnections in general (the overall conference event) is well run, in great locations, and always has a lot of great content that I can benefit from as well.

I've been spending most of my recent prep time fine tuning the demos for my two WCF sessions, Build Event Driven Applications with Indigo and Connecting Smart Client Applications with Indigo. The more I work with Windows Communications Foundation (aka "Indigo"), I am struck by a number of things:

• I am impressed by how capable Indigo is.
• I am awed by how elegant and simple solutions are to complex aspects like security, transactions, queuing, callbacks, and so on.
• I am dumbfounded by how hard it is to figure out how to get to those elegant and simple solutions.

The last bullet is not really a criticism of what they have come up with, it is just the nature of the beast. I would draw on an analogy from my flying days to explain why this is so. Imagine the cockpit of a WW I fighter aircraft. You probably have half a dozen or less simple dials and gauges, and a stick and throttle. Imagine trying to use that set of controls on an aircraft that can fly at high subsonic speeds at high altitude carrying hundreds of passengers for 12 hour transoceanic flights. Not going to work too well. This is basically where you were at with past technologies to build complex, distributed, heterogenous, connected enterprise systems. It could be done, but the end result was not going to be pretty and it was going to take you a long time to get there.

Now with WCF, it is more like climbing into the cockpit of a 777. There is a technological elegance to everything that is there. But there are still hundreds (if not thousands) of individual switches, controls, displays, electronic gages and dials, menu driven control panels, etc. A great deal of human engineering has gone into everything that is in there so that for any given common task, there are only a couple of relevant controls that you have to touch and put into place to get the job done. The challenge is in knowing which one of those hundreds of knobs and dials to tweak.

The same is true for WCF. Microsoft has created an incredibly powerful and technologically advanced platform that is well adapted to building large distributed enterprise systems. In order to do that, there needs to be hundreds of switches and knobs that you can throw to address different scenarios. The downside to that is bullet number three above - you have to learn which switches and knobs are relevant for a given task, and in what order to throw them.

This is somewhat aggravated right now in that we are only at Beta 1 of WinFx (and its parts WCF, WPF, and WinWF), and the names, shapes, and locations of all the knobs and switches is constantly changing as they work on that human engineering task of trying to make it easier to use. Meanwhile the documentation and samples are seriously lagging, so working with it right now is a little like stepping into that 777 cockpit without any labels on the controls. When you say to yourself, "I just need transactions and certificate based security", it is kind of like saying "I just need to call the flight attendant at the second aft flight station". Simple to describe, but God help you in figuring out which switches and knobs to throw. At least there are not really any destructive ones that you can throw by accident. If you get it wrong, your app may not work, but you would have to go out of your way to write some code that would do bad things when WCF fails to let you communicate.

I'm looking forward to continuing to work with this technology and learn what all those knobs and buttons are for. Learning all the controls of the aft cockpit of the F-14 to run the weapons system, navigation systems, communications systems, and other tasks was one of the funnest things I have done in my life. The fact that we got to do that while strapped to a couple of 50K lb + of thrust zorching through the sky pulling G's and landing on the carrier certainly helped make it interesting. Sitting at a computer leaves a little to be desired in that department, but the learning challenge is still just as fun.

I'll be speaking at Visual Studio Connections (part of DevConnections) in Las Vegas from 5-8 November. This is a great and growing conference that happens twice annually in the US, usually Orlando in the spring and Las Vegas in the fall, that I have been privileged to speak at for the last couple years. If you haven't been to one yet, you ought to be hammering your boss for permisson/funding to attend for the following reasons:

• It will rapidly and time-effectively expose you to new solution technologies you might not get a chance to explore on your own
• You will get concentrated advanced training in current and future technologies, getting you up to speed on them in far less time than you can achieve on your own
• You will get presentations from the top speakers in the business
• You will get a chance to network with peers in the industry, learn from others experiences employing .NET technologies, which will make you more effective at employing them yourself
• You will have a lot of fun (OK, maybe don't tell your boss this...)

You can learn a lot peripherally from the conference too by reading the DevConnections blog here. There are posts from other speakers as they develop their talks and their own observations and experiences at the conference.

I'll be presenting the following sessions:

VSM356: Build Custom Data Bound Business Objects and Collections
VSM351: Secure Smart Client ClickOnce Deployments
VID306: Build Event-Driven Applications with Indigo
VID309: Connect Smart Client Applications with Indigo

If you make it to the show (and you should!!), stop by and say hi!