I have finally found the time to finish a new tutorial for XNADevelopment.com. In this tutorial I cover creating an RTS style selection box using a single image. This was a fun little project and I've only done one of many ways this effect can be achieved. I tried to make the code very simple and readable so that most beginners should be able to tackle this exercise.
I've also included a "One Step Further" project, where I took the SelectionBox source code and enhanced it so that you can select "units" and move them around the game window.
The code itself did not take me very long to write. I wrote the original SelectionBox code in an afternoon, simplifying the code so that it was more readable took a lot longer. The hardest part however has been finally forcing myself to sit down and write the tutorial up. Tonight I finally just knuckled down and got it done, I sat down tonight to begin writing at 8 p.m. and just finished up 5 minutes ago at 11 p.m. I think it was totally worth it!
Enjoy!