C# Determinig if exception initialized with a message

Question

Is there a way when catching an exception to determine if it were constructed with a non-default message.

        try
        {
            throw new Exception(message);      // case 1
            //throw new Exception();           // case 2
        }

        catch(Exception exp)
        {
            /* what do I put here such that if the case 2 exception were
               caught it would output exp.ToString() instead of exp.Message? */

            textBox1.Text = exp.Message;  // case 1 handeling

        }

Just to clarify when Exception(message) is thrown I want it to ouptut exp.Message and when Exception() is thrown I want to output exp.ToString(). I would prefer to accomplish this without adding a custom exception. Thanks.

Answer 1

You need to check the message against a default exception

catch (Exception e)
{
  bool isDefaultMessage = e.Message == new Exception().Message;
}

Update

Difference types of Exception

catch (Exception e)
{
  bool isDefaultMessage = false;
  try
  {
     var x = (Exception) Activator.CreateInstance(e.GetType());
     isDefaultMessage = e.Message == x.Message;
  }
  catch (Exception) {} // cannot create default exception.
}