This has happened to me quite a few times, and the answer is annoying simple, and annoyingly hard to find.
When I am typing code in Visual Studio, particularly in C#, I’m very used to the way Intellisense usually works. I type a couple of characters of a method name, for example, and Intellisense shows the completions it can find, with the most likely item highlighted. At that point, it will fill in the completion if I type Enter, or an opening parenthesis, or a dot (if it’s a property – basically whatever the next symbol after the name I want it to enter.
But sometimes, seemingly randomly, it stops highlighting the suggested completion. It’s still the selected item in the dropdown, but now it’s merely selected and not highlighted, and to use it I have to type Tab, or hit the down arrow to highlight it then type the next character after the name. It’s different, not what’s in my muscle memory for typing code. And I could never work out quite why it happened.
I think, previously, I’ve had to completely nuke my Visual Studio settings to get the old behaviour back, which obviously I don’t really want to do. I assumed this was some kind of bug.
But I think I’ve found out why it’s happening, and the VS command to revert it.
The setting is not found in Tools->Options->Intellisense where I was looking, which explains why I didn’t find it.
It’s actually in Edit -> Intellisense -> Toggle Completion Mode, a simple toggle of this behaviour. And it has a shortcut – Ctrl-Alt-Space. I think it’s the shortcut that’s been causing it, as that might possibly be a key combination that I can hit accidentally, although rarelt enough for me not to notice.
But now, I hope I can remember where to find the option. Writing this entry is an effort to make it stick in my memory.
Thanks to Machet on Stack Overflow for pointing the way.