Hi BazzaCAD, make sure you have your using statements at the top of your code file, eg. -
using System;
using System.Runtime.InteropServices;
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using acadApp = Autodesk.AutoCAD.ApplicationServices.Application;
- add others as required. This lets the compiler know which libraries and namespaces you are using.
Also make sure you have any libraries 'referenced' in, right click on 'References' in your solution explorer and choose 'Add reference' and browse for the 2 autocad dll's in the acad directory required to build your project.
A screen shot -