Should the folders in a solution match the namespace?

Question

Should the folders in a solution match the namespace?

In one of my teams projects, we have a class library that has many sub-folders in the project.

Project

Answer 1

@lassevk: I agree with these rules, and have one more to add.

When I have nested classes, I still split them out, one per file. Like this:

// ----- Foo.cs
partial class Foo
{
    // Foo implementation here
}

and

// ----- Foo.Bar.cs
partial class Foo
{
    class Bar
    {
        // Foo.Bar implementation here
    }
}