fix for #240

[smoothdeveloper]

based on investigation from @mrinaldi in #241 and suggestion from @dsevastianov to clear the cache instead of disposing it.

I confirm that in my case it doesn't crash anymore.

[dsevastianov]

@smoothdeveloper This looks much better. The only suggestion is to do actual dispose in this.Disposing.Add, here we do want to get rid of the cache.

[smoothdeveloper]

@dsevastianov good catch, I've just added that explicit call.

[dsevastianov]

Awesome, thanks! One last thing, sorry I didn't catch this earlier - this disposingCache variable should be isDisposing and should be only checked in this.Disposing handler. Here's an explanation, we clear cache on each monitor implementation but clear cache and notification on each monitor change. I hope it makes sense, sorry for all the iterations :)

[smoothdeveloper]

@dsevastianov thanks for feedback, I'm not sure I'm following, I renamed the variable clearingCache to isDisposing and only flip it in Dispose implementation, and I also extracted a class for the cache because I think we eventually want to put it under tests.

I hope it looks ok now :)

[dsevastianov]

@smoothdeveloper Released 1.8.3-beta4, thanks for your patience!