UI

My ultimate INotifyPropertyChanged implementation

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In the Model-View-ViewModel design pattern, we make frequent use of the INotifyPropertyChanged interface. It is the Interface that defines the necessary methods to Notify the UI when a Property has Changed. As you can see, its a very well-named Interface. 🙂

I’ve collected a few variations of the implementation and placed them all into a single ViewModelBase class. I didn’t write any of these myself – rather, I found them strewn about the internet. I’ve documented where I got some of them; others were (and probably still are) readily available from a multitude of sites. I’m making my collection available here, and I’ll give a few examples of how to use it. I’ll also explain the “evolution” my use of this interface has undergone.

To keep things organized, I usually create a folder named MVVM in my solution to house this class. You’ll want to update the namespace in this class to match your project; eventually I’m sure I’ll just compile it into a DLL once its evolution has ceased. Continue reading

Keep your UI responsive with the BackgroundWorker

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I recently completed an application that made use of the WebClient object’s DownloadString method to obtain a JSON string. In my development environment retrieval of this data often took upwards of 30 seconds. If you’ve ever incorporated a time-consuming process in your application, you may have noticed that your user interface becomes unresponsive while the process is running.

Why does this happen? Because without special consideration, this time-consuming process is running on the same thread that handles updating of the UI. “How do I keep my UI responsive during a time-consuming process?”, you may ask. This can be easily accomplished through the use of the BackgroundWorker object. In this article, we’ll discuss the BackgroundWorker object, some of its available event handlers, and one of its methods. Continue reading