Spot the Signs. According to Alison Green, who writes the blog Ask a Manager, this is common practice for some industries, especially if you're leaving to work for a direct competitor. However, in those situations, you'll likely know it's coming and can prepare accordingly.
Acceptance With Displeasure. It's possible that your boss won't take immediate action like the reaction above__but will make it clear that he or she isn't exactly happy about your resignation. Maybe, for example, she'll mutter a curt, "Thank you for letting me know," followed by two weeks of obvious displeasure or denial that you're leaving__through gruff comments ("You know, you're really leaving us in the lurch") or a refusal to interact with you more than absolutely necessary.