c# - Return a String with LuaInterface -

so, i'm trying implement lua scripting language in c#. it's simple enough, really, if use part of console application. want able create game console within xna. problem lua.dostring() seems return console line, rather string - which, said, fine console applications, want add output buffer string can display in-game, rather in console window. apologize if confusing - code clear up.

using system; using system.collections.generic; using luainterface;  namespace luaconsolelibrary {     public class luaconsole     {         private lua lua;          private bool isrunning = true;         private string input;         private list<string> outputbuffer;          public bool isrunning         {             { return isrunning; }         }          public luaconsole()         {             this.lua = lua;         }          public void run()         {             int = 0;             while(isrunning)             {                 outputbuffer.add("> ");                  input = console.readline();                 outputbuffer.add("");                  try                 {                     lua.dostring(input);                 }                 catch(exception e)                 {                     outputbuffer.add(e.message);                 }                                 {                     outputbuffer.add("");                 }             }         }     } } 

basically, i'm confused why lua.dostring(input); should work opposed having use console.writeline(lua.dostring(input));. i've tried outputbuffer.add(lua.dostring(input).tostring());, which, being tostring valid there, should work in theory. instead performs lua.dostring , throws exception - "object reference not set instance of object". unless i'm mistaken, object in question lua, makes lua valid object reference. anyway, seeing these 2 solutions don't work, wondering if knows enough luainterface suggest alternative way same result. want effect of outputbuffer.add(lua.dostring(input));. way, lua command i've been using test print("test") - maybe print somehow returning console line instead of string, can't think of way return string lua.

i apologize if problem rambling or poorly explained - tried concise possible, it's kind of niche issue , don't know how else explain it, really. oh, , did try google, , browsed 65 or luainterface questions on stack overflow, i'm 95% sure i've done due diligence before asking question. luainterface not well-known of tool, guess.

object reference not set instance of object c#'s way of saying "something null , shouldn't be."

in case, dostring returning null, null.tostring() raising exception. try outputbuffer.add(convert.tostring(lua.dostring(input)[0])) if want convert string without throwing on nulls.

i haven't used either luainterface or nlua, i'd guess return string you'd have execute return "test" lua command.