I put together a minor upgrade to all my apps — correcting a couple of things I didn’t like in them, and adding a way for users to see all my apps — and they’ve been coming back from the certification folks just fine, except for my most ambitious app!  It got rejected, O, woe is me!

Hey, my rejects thus far have pretty much been for goofing up on the background thing — you know, when the user changes the background to the light instead of the dark background, and suddenly the white words on the screen can’t be seen!  The solution of course is to change the background color of the Grid control containing the words from the default of “Transparent” to something contrasty.  But not this time.

Keep in mind that the Fraction Calculator does not cut corners when it comes to calculating, and some fraction arithmetic, especially with large fractions containing denominators that don’t have many common factors, takes a LOOOOONNNNNGGGG time, even for a computer.  Fine, the app warns the user that the calculation is going to take awhile and confirms that the user wants to go ahead anyway.  But what happens if the user suddenly gets a phone call, or has to leave the Fraction Calculator in the middle of the operation?  Well, the tester found out and told me.  And this is the problem: Fraction Calculator does NOT tombstone properly.  Try to come back to the app after leaving it and it just doesn’t come back.  Yuck.

This particular problem wasn’t discovered in the initial testing, which the tester acknowledged, but I am glad it came up now.  This is because the calculation process is quite amenable to going on break while in the midst of working.  I just have to figure out how to save state on the process so I can resume it upon coming back online.

There’s fortunately a tutorial on the subject of tombstoning in the education section of the App Hub.  It’s in the QuickStarts, HERE.