As a felon myself, I have never had anything good come out of early disclosure. I think your best bet would be to target jobs in areas that have "banned the box" for private employers (I believe Chicago is one of these cities). If you receive a conditional offer of employment, they will most likely run a background check at that point. Some lower quality background checking services can provide surprisingly incomplete results. More than likely though, it will return your conviction history. Once you get that call from the HR representative questioning the conviction, simply state that you didn't feel it was relevant to the position being applied for. Refer them to the EEOC guidelines on hiring people with felony convictions (especially the part about individualized assessments). These guidelines are merely a suggestion, but it might be enough to sway the mind of someone in the company who has that discretion.
The C# ecosystem might be less than ideal for you to spend your time learning. Start thinking about how certain programming languages might correlate with certain types of industries. You're going to want to target companies that are less likely to bother checking in to your background, and if they do, are less likely to care. Think more along the lines of hipster startup development and less along the lines of conservative enterprise development. This might mean focusing your efforts on learning the Javascript of Python ecosystems instead.
I'm a federal felon myself and have found success by applying to companies based in states/cities which have "banned the box" for private employers. I'm currently working in a very respectable software engineering position, in a region which hasn't banned the box. The largest part of this companies workforce however, is based in an office located in a state which HAS banned the box for private employers. They never had a felony conviction checkbox for me to check on the job application, and they didn't bother running a background check which included the federal system. I've found that probably only around 50% of companies will include a federal background check. When it comes to background checks for housing or background checks for recruiting agencies, virtually none of them will do this.