how to add pop up messages to a document in visual studio

i want to write a macro or 开发者_如何学运维add-in in visual studio which will pop up a message above some words in the active document, just cant find the way. plz :D

I'm torn on whether or not to vote to close this as a duplicate, but you didn't specify the Visual Studio version. If 2010, it's been covered and this may help you. If 2008 (and I think the same was true for 2005, and the documentation goes back to 2003 as well), there seems to be a good bit of documentation on MSDN.