How can I make a variable accessible to another class within the same project?

Question

I have a variable (PrincipleIndex) in a class (Principles.cs) in one C# project (..\\Bullseye\\Biz Logic\\Trading\\Principle\\Data\\Principles.cs

Answer 1

Just add:

private int principleIndex = 0;

public int PrincipleIndex 
{
    get { return principleIndex; }
}

...
    // this must be within the Principles class
    Principles.Instance.principleIndex = Principles.Instance.RowIndexToPrincipleIndex(hti.Row);
...