When should I use a ThrowHelper method instead of throwing directly?

Question

When is it appropriate to use a ThrowHelper method instead of throwing directly?

void MyMethod() {
    ...
    //throw new ArgumentNullException(\"param         


        

Answer 1

One advantage not yet mentioned to using either a throw-helper or exception-factory method is the possibility of passing a delegate for such a purpose. When using a throw-helper delegate, one gains the possibility of not throwing (which would in some cases be a good thing; in other cases, a bad thing). For example:

string TryGetEntry(string key, Funct errorHandler)
{
  if (disposed)
    return errorHandler(problemCause.ObjectDisposed);
  else if (...entry_doesnt_exist...)
    return errorHandler(problemCause.ObjectNotFound);
  else
    return ...entry...;
}
string GetEntry(string key)
{
  return TryGetEntry(key, ThrowExceptionOnError);
}
bool TryGetEntry(string key, ref result)
{
  bool ok;
  string result;
  result = TryGetEntry(key, (problemCause theProblem) => {ok=false; return (string)null;});
  return ok;
}

Using this approach, one may easily use one routine with a variety of error-handling strategies. One could eliminate the need for a closure by having the TryGetEntry method accept a generic type parameter along with a 'ref' parameter of that type and a delegate that accepts such a 'ref' parameter; the example is simpler, though, just using a closure.