Please do not take this as harsh. It is not meant that way at all. But why are you trying to go so fast? You still have a million questions about C# and the .NET framework, and here you go hop-hop-hopping off after WPF. And immediately posting questions on that topic. Maybe there is some good reason you need to go fast. We have not met and I know nothing about your personal circumstances.

One of the reasons I decided to say this is I sometimes do the same thing myself. I go hop-hop-hopping after the new before mastering its predecessor. Like double cheeseburgers, fries, and a Coke for lunch, I know it's not good for me, yet I do it anyway.

The late, great Tom Rettig posted something on the old Compuserve FoxForum probably 15 years ago now that I have never forgotten. He said while it's really smart sometimes to ask the question here before spinning your wheels too long, at other times, when you're learning as opposed to an experienced pro stuck on an esoteric issue, there is no substitute for going offline, rolling up your sleeves, and doing the hard, thankless work of learning it to the point that you truly grok it. (Or words to that effect; this is from memory. And he undoubtedly wrote it more gracefully than that). That is advice I have tried to heed. Not always successfully, but I know it's the right way to go.

In any case, however you decide to approach it, good luck with .NET! May you become a Jedi master.