Better Commands in WPF

When I explain commands in WPF, I tend to say they are simply “bindable methods.” I like this definition not only for its brevity, but for its composition of powerful ideas into a single construct. It reinforces the axiom of “no code left behind” that we push so hard in WPF. But this leaves behind almost two thirds of the functionality given to us by ICommand the parameter and CanExecute. Parameters, admittedly, are needed less often in most designs, as commands tend to operate on the view model to which they are attached. CanExecute, on the other hand, is used fairly often and is also fairly broken in most implementations. Continue reading “Better Commands in WPF”

Coercing ViewModel Values with INotifyPropertyChanged

Perhaps one of the most ambivalent things about putting code on GitHub is that it’s more or less an open project. It’s great that people (including yourself) can continue to work on it, but it seems to lack closure so that you can move on with your life.

So one of the things that I’ve been missing in my BindableBase class is property coercion, a la dependency properties. It’s a pretty smart idea; you can keep values in a valid state without pushing change notification. Unfortunately, there are some problems that crop up pretty quickly in INotifyPropertyChanged based view models. Continue reading “Coercing ViewModel Values with INotifyPropertyChanged”

The Right Way to do INotifyPropertyChanged

It’s sad how much controversy there is in doing something as simple as raising property change notification to our subscribers. It seems to me that we should have settled on something by now and moved on to bigger problems, yet, still, I see developers at every level of experience doing it differently.

I want to inform you all that you’re doing it wrong. Continue reading “The Right Way to do INotifyPropertyChanged”

How to Actually Change the System Theme in WPF

When I first started working with WPF professionally, it wasn’t very long before I realized I needed to change the system theme of WPF to give my users a consistent experience across platforms. Not to mention that Vista’s theme was much improved over XP and even more so over the classic theme. Conceptually, this should be feasible, since WPF has its own rendering engine, as opposed to WinForms relying on GDI. Continue reading “How to Actually Change the System Theme in WPF”

The Extension Method Pack

Since .NET 3.0 came out, I’ve been enjoying taking advantage of extension methods and the ability to create my own. The thing I’ve noticed is that a handful of them are useful to almost any application, above and beyond what Microsoft provides in System.Linq. So over the last few days I took the time to gather these methods together, unit test them, and run them through FXCop to make a high-quality package ready to go in any application with a little re-namespacing.

I’ve broken each code sample into independent blocks wherein all necessary dependencies are contained, so you can take any extension method a la carte or you can get everything from the attached zip file. My solution was built in .NET 4.0 in Visual Studio 2010, but everything should work just fine in .NET 3.5 with Visual Studio 2008.

Also included in the zip file are my unit tests, which may help you understand usage of some of the more esoteric extensions, such as ChainGet, and XML comments for your IntelliSense and XML documentation generator.

Edit: The whole solution is now available on github!

Continue reading “The Extension Method Pack”