Q:

How to use class from other project in visual studio C#

I have a Xamarin.Forms project and a C# console app project. I want to use one class from the console app in my Xamarin.Forms project.
I added the console app project to the solutions explorer of the Xamarin.Forms project.
Unfortunately, I can't figure out how to use the class from the console app in one of the Xamarin files. 
I always get the error message: 

The name 'MyClass' does not exist in the current context.

I tried to press alt+enter to show potential fixes but it does not offer me the option of importing/using the class.
I also wrote manual using directives in various forms but it still does not seem to make the class accessible.
The only way I was able to use the class was by adding the class directly to the Xamarin project by adding it with add->existing item. The problem with this is that it imports a copy of the class. Since I'm still working on the class within the other project the added class is fast outdated and I have to manually copy its contents over. 
How can I use a class from an external project without making a copy of the file?

A:

Try to add a reference to the second project in your first project. To do this, right-click on your project, select Add Reference then select the project in your solution. Once your main project references the second project, then you can access its public types.

