dart - How to detect if app is still not closed?

Question

I am writing Dart app. During using of it user can run long server processing. Complex SQL select query. I want stop SQL processing if user is closed app window.

1. Is it possible on mobile?
2. Is it possible with Dart for web?

question from:https://stackoverflow.com/questions/65641393/how-to-detect-if-app-is-still-not-closed

Answer 1

Waitting for answers