When our WPF programs don't work as expected, we need to debug them, as we would with any other language. However, at first it can seem to be a daunting task, as WPF is very different from other languages. For example, when declaring a Dependency Property, we normally add a CLR property wrapper for convenience. However, the WPF Framework won't call it when the property value is changing, so we'd wait a long time for a break point in that setter to be hit.

When we're testing our newly developed code, we need to be able to check the values of our data bound properties, and there are a number of ways to do that, although some are far from obvious. In this chapter, we'll investigate a number of important sources of information to help us to locate the mistakes in our code.

We'll discover a variety of tactics to help us when debugging the data bound values and find out how to track down the actual cause of a problem when faced with the dreaded XamlParseException. We'll cover all of these topics in detail shortly, but for now, let's first start with the absolute basics.