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

You can use a private property that checks to see if it was assigned to and only assign a value if it hasn't been.

int? _writeOnceField;

private int? WriteOnce
{
   set
   {
      if (!_writeOnceFiled.HasValue)
      {
        writeOnceFiled = value;
      }
      else
      {
        // Throw exception
      }
   }
}