Plugins.cs

using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;

// This line is not mandatory, but improves loading performances
[assembly: ExtensionApplication(typeof(Ecogy.Plugins))]

namespace Ecogy
{
    // This class is instantiated by AutoCAD once and kept alive for the 
    // duration of the session. If you don't do any one time initialization 
    // then you should remove this class.
    public class Plugins : IExtensionApplication
    {
        void IExtensionApplication.Initialize()
        {
            // Add one time initialization here
            // One common scenario is to setup a callback function here that 
            // unmanaged code can call. 
            // To do this:
            // 1. Export a function from unmanaged code that takes a function
            //    pointer and stores the passed in value in a global variable.
            // 2. Call this exported function in this function passing delegate.
            // 3. When unmanaged code needs the services of this managed module
            //    you simply call acrxLoadApp() and by the time acrxLoadApp 
            //    returns  global function pointer is initialized to point to
            //    the C# delegate.
            // For more info see: 
            // http://msdn2.microsoft.com/en-US/library/5zwkzwf4(VS.80).aspx
            // http://msdn2.microsoft.com/en-us/library/44ey4b32(VS.80).aspx
            // http://msdn2.microsoft.com/en-US/library/7esfatk4.aspx
            // as well as some of the existing AutoCAD managed apps.

            // Initialize your plug-in application here

            Application.EnterModal += Application_EnterModal;
        }

        private void Application_EnterModal(object sender, System.EventArgs e)
        {
            try
            {
                Commands.GoogleDrive();
            }
            finally
            {
                // Basically ignore this for now, as it's most likely they just haven't run the command
            }
        }

        void IExtensionApplication.Terminate()
        {
            // Do plug-in application clean up here
        }

    }

}