Unity Project doesn't have solution file

Question

I just started learning unity and I created a project. But my project doesn't have a sln file included in. Every time I create a C# script and open it in Xamarin Studio I can't have any intellisense.

1. Is it normal not to have sln file in unity project?
2. If not, how can I add solution file to project?
3. Why that happened?

Answer 1

If "Open C# Project" doesnt create the .sln file, try updating your external tools first.

In Unity, go to Edit > Preferences, and make sure that Visual Studio is selected as your preferred external editor.

This created the sln file for me.

Answer 2

I finally found the answer.

I closed Xamarin and inside Unity went Assets > Sync MonoDevelop Project Doing this created the two .sln projects: -csharp.sln and .sln