Launching a Stand-alone Executable

A colleague of mine asked for some help implementing a Revit add-in to launch an external stand-alone Windows executable from the Revit user interface.

Since this might be useful to others as well, here is a summary of our discussion and solution:

Question: I am working on a windows application using GBS API to perform building parametric analysis (energy consumption in terms of comparison of window glazing materials, building orientation). Currently, I am exporting the gbxml file, saving it on my desktop and using the gbxml file in GBS simulations.

I would like to know if I can directly export the gbxml file to my windows application and run the simulation by creating a Revit add-in of my windows application.

Answer: I do not understand the difference between the two:

1. Exporting the gbxml file, saving it on my desktop and using the gbxml file in GBS simulations.
2. Export the gbxml file to my windows application

The only gbxml export option provided by the Revit API is the Export method:

  public bool Export(
    string folder,
    string name,
    GBXMLExportOptions options )

It produces the same result as exporting to gbxml manually.

Response: I have been working on other parts of my sample.

I now want to create an add-in feature in Revit that executes my windows desktop application. Can you help me to identify the code to perform this?

I would like to know what code I am supposed to follow to create a Revit add-in of my .exe file.

Answer: Do you mean you want to launch a stand-alone Windows executable from your C# .NET add-in?

The answer is provided immediately by a standard Internet search, e.g. for c# launch exe.

You cannot create a Revit add-in from an exe file.

You can however easily launch an external executable from a Revit add-in.

Response: If it does not take too much of your time it would be great if you could write it for me.

I do have Visual Studio installed.

Thank you for your help.

Answer: Here is RvtLaunchExe.zip containing the complete source code, Visual Studio solution, and add-in manifest.

It also includes a sample executable:

The sample exe just displays a dialogue box:

Its entire implementation looks like this:

  using System;
  using System.Windows.Forms;
 
  namespace SampleExe
  {
    class Program
    {
      static void Main( string[] args )
      {
        MessageBox.Show( "Hello Shalini.",
          "Sample Executable" );
      }
    }
  }

If you open the Visual Studio solution and compile, the whole thing should install itself, i.e. copy the add-in manifest and assembly DLL to the proper location for Revit to find and load them.

Revit will then display the add-in ribbon panel:

Simply click the button to do the dirty deed.

The external application defines the ribbon panel and command button like this:

#region Namespaces
using System;
using System.Collections.Generic;
using Autodesk.Revit.ApplicationServices;
using Autodesk.Revit.Attributes;
using Autodesk.Revit.DB;
using Autodesk.Revit.UI;
using System.Reflection;
#endregion
 
namespace RvtLaunchExe
{
  class App : IExternalApplication
  {
    /// <summary>
    /// Add our command button to the ribbon panel.
    /// </summary>
    void PopulatePanel( RibbonPanel p )
    {
      string path = Assembly.GetExecutingAssembly()
        .Location;
 
      RibbonItemData rid = new PushButtonData(
          "RvtLaunchExe_Command",
          "Launch External\r\nWindows Executable",
          path, "RvtLaunchExe.Command" );
 
      rid.ToolTip = "Launch an external "
        + " stand-alone Windows executable";
 
      p.AddItem( rid );
    }
 
    public Result OnStartup( UIControlledApplication a )
    {
      PopulatePanel(
        a.CreateRibbonPanel(
          "Launch Executable" ) );
 
      return Result.Succeeded;
    }
 
    public Result OnShutdown( UIControlledApplication a )
    {
      return Result.Succeeded;
    }
  }
}

Clicking the button launches the external command. It calls the LaunchExe method, which simply uses the .NET System.Diagnostics process functionality to launch the external executable:

#region Namespaces
using System;
using System.Diagnostics;
using System.IO;
using Autodesk.Revit.Attributes;
using Autodesk.Revit.DB;
using Autodesk.Revit.UI;
#endregion
 
namespace RvtLaunchExe
{
  [Transaction( TransactionMode.ReadOnly )]
  public class Command : IExternalCommand
  {
    const string _standalone_exe_path
      = "C:/a/vs/RvtLaunchExe/SampleExe/bin/Debug/SampleExe.exe";
 
    int LaunchExe( string path )
    {
      if( !File.Exists( path ) )
      {
        throw ( new ArgumentException( string.Format(
          "'{0}' not found.", path ) ) );
      }
 
      int rc = 0;
 
      // Prepare the process to run
 
      ProcessStartInfo start = new ProcessStartInfo();
 
      // Enter the command line arguments, everything 
      // you would enter after the executable name.
 
      //start.Arguments = arguments;
 
      // Enter the complete executable path
 
      start.FileName = path;
 
      // Do you want to show a console window?
 
      start.WindowStyle = ProcessWindowStyle.Hidden;
      start.CreateNoWindow = true;
 
      // Run the external process and 
      // wait for it to finish
 
      using( Process proc = Process.Start( start ) )
      {
        proc.WaitForExit();
 
        // Retrieve the external application exit code
 
        rc = proc.ExitCode;
      }
      return rc;
    }
 
    public Result Execute(
      ExternalCommandData commandData,
      ref string message,
      ElementSet elements )
    {
      int rc = LaunchExe( _standalone_exe_path );
 
      if( 0 != rc )
      {
        message = string.Format(
          "{0} returned error code {1}",
          _standalone_exe_path, rc );
 
        return Result.Failed;
      }
      return Result.Succeeded;
    }
  }
}

I hope this covers all you need and is useful to others as well.

After all, it does provide a really minimal example of setting up one single ribbon button and one single trivial external command with an absolute minimum of fuss and effort.