Readonly field that could be assigned a value outside constructor

Question

Is there a way to have a private readonly field in a class that could be assigned a value anywhere in the class, but only once??

That is, I am looking for a private read

Answer 1

I think I achieved a way to do it, if it is done in the constructor. It could also be on the variable declaration line. If done outside those contexts, you will receive an error: A readonly field cannot be assigned to (except in a constructor or a variable initializer)

public class BillLine
{
    public BillLine(Bill bill)
    {
        m_Bill = bill;
    }

    private readonly Bill m_Bill;

    public Bill Bill
    {
        get { return m_Bill; }

        //supposed to be set only in the constructor
    }

    //(...)
}