I’ve been spending a lot of time in WPF-land over the past few weeks, and thought I’d share some of what I’ve learned. I haven’t been learning styles or UI layout stuff – Microsoft says that’s the job of the turtleneck-wearing, metrosexual GQ crowd, so I’ll just roll with that. Instead, I’ve been learning how to write data source provider controls, and implement Windows Forms-like behaviors similar to the ErrorProvider and my Csla.Windows.ReadWriteAuthorization control. You know, manly programming J The data source provider control is, perhaps, the easiest thing I’ve done. Like ASP.NET, WPF likes to use a data control concept. And like ASP.NET, the WPF data provider controls are easy to create, because they don’t actually do all that much at runtime. (I do want to say thank you to Abed Mohammed for helping to debug some issues with the CslaDataProvider control!) I’m sure, as designer support for data provider controls matures in tools like Visual Studio and Expression Blend, that life will get far more complex. Certainly the Visual Studio designer support for Csla.Web.CslaDataProvider has been the single most time consuming part of CSLA .NET , though I was able to create the runtime support in an afternoon… What I have today, is a Csla.Wpf.CslaDataProvider control that works similar to the ObjectDataProvider. The primary difference is that CslaDataProvider understands how to call Shared/static factory methods to get your objects, rather than calling a constructor method. The result is that you can create/fetch CSLA .NET business objects directly from your XAML. The really cool part of this, is that CslaDataProvider supports asynchronous loading of the data. To be fair, the hard work is done by the WPF base class, DataSourceProvider. Even so, supporting async is optional, and requires a bit of extra work in the control – work that is worth it though. If you construct a form that has multiple DataContext objects for different parts of the form, loading all of them async should give some nice performance benefits overall. On the other hand, if your form is bound to a single business object the value isn’t clear at all. Though the data load is async, the form won’t actually display until all the async loads are complete, so for a single data source on a form my guess is that async is actually counter-productive. The validation/ErrorProvider support is based on some work Paul Stovell published on the web. I conceptually based my work on similar concepts, and have Read More...