What is hotkey in c#?

If you don't know what it is, how can you need it ? It's just where you associate a key with a menu item in the properties, so pressing that key combo chooses that item. I would recommend you buy a basic C# book and read it so you know a few basic things about what you're doing before you start asking questions. That way, you can also ask questions that are more likely to lead to a real answer, I suspect you're confused about what hotkeys do, and therefore that you're still no closer to what you want to achieve.