Every now and then a question comes up concerning a missing DataContext.  The questions usually center around a ViewModel being set to a View properly, but then developer can not bind some command or property to a FrameworkElement.  And typically the FrameworkElement in question is nested within an ItemsControl’s ItemTemplate or other ...

This week I was debugging a problem with a WPF application.  Actually, it being a WPF app had little to do with the problem.  No, what I was testing was the installer process.   We’re writing a new WPF frontend for an existing system and the application needs to  installed via a InstallShield installer.  It’s a legacy ...

A fair portion of the time, the content of a FrameworkElement is text. Some elements, like TextBox and TextBlock make this obvious, by providing a Text property. The Text Property is of type String and it trivially easy to set in XAML. [example]   <TextBlock Text='This control is intended to show text' /> Other ...

The purpose of this post is to provide an introduction to the Model-View-ViewModel (MVVM) pattern. While I've participated in lots of discussions online about MVVM, it occurred to me that beginners who are learning the pattern have very little to go on and a lot of conflicting resources to wade through in order to try to implement it in their own ...

The observer pattern is well established and used. The typical scenario is to register to an class and then allow your Notify method to be called. This often involves keeping an internal list of observers and then iterating them to notify that something has changed. I had a situation recently that warranted a lighter weight approach that allows a ...

This is one of those quirks that until you try it, you may not know it exists or what the answer is. I am working on a WPF project and have a separate control library (actually, a module because I am using the Component Application Guidance/PRISM pattern). I pulled it into Expression Blend and was surprised to see that I had no ''design'' view. ...

A question appeared on StackOverflow asking how to animate a property on multiple elements from one or more trigger mechanisms (i.e. a button click or list box selection).  The traditional approach (for brevity’s sake, I omitted the Xaml comprising the actual UI elements) is rather straight-forward: <Window.Resources> ...

I recently had the pleasure of speaking at CodeStock 2009 and was very impressed with the conference overall.  The folks behind this conference put in a lot of work and did a really great job.  I got the chance to see some really good presentations as well.  I look forward to attending CodeStock in the future.  The code and ...

Data is at the heart of virtually any business application.  WPF ships with a flexible data binding engine that simplifies writing data centric applications.  I spend a lot of time during my WPF class talking about this data-binding feature.  In fact I devote three sections during the week to this topic. Last week I added a new ...

The last couple months have been a hectic flurry of activity. Not only have I been at several conferences and the MVP summit I've also been putting the finishing touches on our Mastering Microsoft Surface™ Development with WPF class.  This class is going to be a lot of fun to teach.  First of all the class is chock full of WPF ...