I have a working WPF application. I would like to see it running as an xbap. What do I need to change in my WPF app to make it run as an xbap?
When it comes to what you can do graphically, the only difference between the two is that XBAP can't use BitmapEffects. Other than that, the sandbox security issues are pretty much the only things you need to deal with. Most pure WPF programs should transition smoothly.
Check out this comparison of the differences between WPF and XBAP.
Here's a tutorial for creating an XBAP application.
Based on that there's a fairly simple refactor you can do to accommodate both WPF and XBAP for your program.
Yes, we can use Windows in XBAP. But the first object must be a Page, because the Page will be displayed on the browser. You can put a button on the page and open your window from it.