The Automation part of the .NET API is a small assembly that can be referenced by developer applications. It contains enough to start Navisworks and perform some basic actions; however complex actions should be achieved using a plug-in which can still be called through Automation. Here we will create a simple Application to demonstrate the rudiments of creating an application using the Automation features to merge two AutoCAD DWG files into a single Navisworks NWD file.

Note
the same set of actions that can be invoked in Automation can also be invoked from the Navisworks command line.

This example can be found in: '<drive>:\Program Files\Autodesk\Navisworks <Product> 2015\api\net\examples\Automation\FileManipulation'

Overview

Step	Key Information
Create Blank Project
Add API Reference	Autodesk.Navisworks.Automation.dll
Add any other references
Add implementation
Build
Run Program	This program takes input from two AutoCAD .DWG files which can be copied from the FileManipulation sample into the project output directory.

To create an application using Automation

Create the calling application.
Add the required API references.

Add the code which merges two files (hello.dwg and world.dwg) into a single Navisworks file (hello_world.nwd):

CopyMerging Files into a Navisworks Document

Autodesk.Navisworks.Api.Automation.NavisworksApplication automationApplication = null;
try
{
   //Get Current Working directory
   string workingDir = System.IO.Directory.GetCurrentDirectory().TrimEnd('\\');

   //create NavisworksApplication automation object
   automationApplication =
      new Autodesk.Navisworks.Api.Automation.NavisworksApplication();

   //disable progress whilst we do this procedure
   automationApplication.DisableProgress();

   //Open two AutoCAD files
   automationApplication.OpenFile(workingDir + "\\hello.dwg", workingDir + "\\world.dwg");

   //Save the combination into a Navisworks file
   automationApplication.SaveFile(workingDir + "\\hello_world.nwd");

   //Re-enable progress
   automationApplication.EnableProgress();
}
catch (Autodesk.Navisworks.Api.Automation.AutomationException e)
{
   //An error occurred, display it to the user
   System.Windows.Forms.MessageBox.Show("Error: " + e.Message);
}
catch (Autodesk.Navisworks.Api.Automation.AutomationDocumentFileException e)
{
   //An error occurred, display it to the user
   System.Windows.Forms.MessageBox.Show("Error: " + e.Message);
}
finally
{
   if (automationApplication != null)
   {
      automationApplication.Dispose();
      automationApplication = null;
   }
}

Calling plug-ins through Automation

It is also possible to invoke a plug-in using Automation and to receive a reply in the form of a status code. For example:

CopyInvoking a plugin through Automation

string aString = "Hello";

Autodesk.Navisworks.Api.Automation.NavisworksApplication navisworksApplication =
   new Autodesk.Navisworks.Api.Automation.NavisworksApplication();

// Execute command on our message receiver
int retval = navisworksApplication.ExecuteAddInPlugin("BasicPlugIn.ABasicPlugin.ADSK", aString);

//Show the result received from the plugin
MessageBox.Show(String.Format("Plugin returned {0}", retval));