Creating the class library

So how do we begin to extend the Burn UI? In short, we will build a C# class library (.dll) that references BootstrapperCore.dll. Our class library will then be referenced within our bootstrapper markup. When the bootstrapper starts up, it will have been configured to use this assembly. Our assembly will have WPF code inside of it, ready to show a window as it simultaneously drives forward the Burn engine. Clicking a button on our UI will call methods provided by BootstrapperCore. Simple, right? Let's dive into it.

Create a new C# Class Library project in Visual Studio and name it CustomBA. Once you have it, add a reference to BootstrapperCore.dll, which can be found in the WiX SDK directory. To use WPF, we'll also need to reference the following .NET assemblies:

• PresentationCore

• PresentationFramework

• System.Xaml

• WindowsBase

We'll be using the Model-View-ViewModel (MVVM) pattern to organize the code. This will allow us to keep our UI and backend layers decoupled...