为笔记本电脑开发自定义屏幕显示应用程序

I would love to create a custom on-screen display app for my laptop, seeing as the manufacturer-supplied one is utter garbage. I'm out to write an app that will show things such as volume control, screen brightness, wireless antenna status and so forth. I'm not sure what info I'd need to know to begin creating something like this (interfaces for grabbing key/button presses, system priority, any other relevant data) and wondered if anyone could help point me in the right direction. If possible I'd like to develop it in C#.I would love to create a custom on-screen displ