I am in the process of converting an Add-In from VB ArcObjects to an ArcGIS Pro Add-In written in C#. The original Add-In was designed using Windows Forms as modal Dialogs. The documentation for the Event Model and Properties of Windows Forms was easy to understand and implement for the adding and using controls on the form.
The ProWindow UI template appears to be the closest equivalent to a Windows Form for the ArcGIS Pro Add-In. I have created a project with a ProWindow and added WPF controls that replicate my original Windows Form dialog, but I I don't know anything about what to do after that. The Microsoft documentation examples for WPF are causing errors and I don't understand how to connect the dots.
For example, how do I add a button to a ProWindow and handle the button Click event to open a MessageBox saying the button was clicked as the stub code that I can eventually replace.