var commandString = string.Format("_.mirror _C\r{0}\r{1}\r {2}\r{3} _n\r",
pEnd.ToString2D(), pStart.ToString2D(), axialPStart.ToString2D(), axialPEnd.ToString2D());
_acadCurrentDocument.SendCommand(commandString);
does not work, i believe it is because \r.
How to pass trough this situation?
I don’t have an AutoCAD handy to test here, but I believe
\ralone is not recognized by the command interpreter as a press on theENTERkey. Try using\ninstead: