We Keep Coding

Revit API: Is SetLayerSelection the best solution?

Our company has hundreds of legacy AutoCAD details to choose from to import into Revit. We are using Revit 2021 and C# (Visual Studio 2019) to access the Revit API. We already have the code to create the drafting views and import the DWG files. What we still need to figure out is how to NOT import certain layers (i.e., Defpoints), and how to change the line graphics (color and/or line weight) on a per layer basis. Normally this is done via the VG Overrides dialog in Revit, but we would like to do it programmatically during the import process. Which of the following is best practice?
Solution #1: Import only “visible” layers. This is our current, and less than ideal, solution and requires turning off layers manually before the import.
DWGImportOptions options = new DWGImportOptions
{
VisibleLayersOnly = true,
};
doc.Import(#detailfilename, options, detailview, out elemId);
Solution #2: Use the SetLayerSelection method under the DWGImportOptions class. This requires that an ICollection object be passed to the method that contains the layers to be imported. How are the layers read from the DWG file into the ICollection object? A snippet of code would be greatly appreciated.
Solution #3: Something else we have not thought of.
Thank you in advance for your assistance and expertise. Snippets of code would be greatly appreciated.

Afaict, the method of choice to generate the lists of layers to import would be to implement an AutoCAD.NET application that reads the existing layers in every DWG file and processes them according to given rules.
Since that requires AutoCAD.NET work anyway, I would go whole hog and implement full preprocessing of the DWG files in that app, so that nothing more than you already have remains to be done in the Revit API.
My personal 2c only, of course.

Thank you Jeremy Tammick. I am curious if the code from your 4/12/2013 blog post could be used. I modified that code as follows, but the Open command throws an exception: "Method not available in MDI mode. Use Open method of Documents collection". Any thoughts? Many thanks.
[TransactionAttribute(TransactionMode.Manual)]
public class OpenDWG : IExternalCommand
{
public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
{
Autodesk.AutoCAD.Interop.AcadApplication app = new Autodesk.AutoCAD.Interop.AcadApplication();
Autodesk.AutoCAD.Interop.AcadDocument adoc = app.Documents.Application.ActiveDocument;
string pfile = "C:\\Testfile.dwg";
adoc.Open(pfile); //this command throws an exception
//add more code here to turn off unwanted layers
adoc.Save();
app.Quit();
return Result.Succeeded;
}
}

ICE: trying to add a local var with the same name, but different types. during [_RegisterClipboardFormat]

I have a PoC to use some existing Java-codebase in some UWP-app using the most current Visual Studio Community 19 version 16.3.2 and the latest released IKVM 8.1.7195.0. The app builds and runs fine in Debug-mode, but fails to build already in Release-mode with the following error:
MCG0004:InternalAssert Assert Failed: ICE: trying to add a local var
with the same name, but different types. during
[_RegisterClipboardFormat] Ams.Oms.Poc
RegisterClipboardFormat is part of IKVM:
#DllImportAttribute.Annotation(value = "user32.dll", EntryPoint = "RegisterClipboardFormat")
private native static int _RegisterClipboardFormat(String format);
#cli.System.Security.SecuritySafeCriticalAttribute.Annotation
private static int RegisterClipboardFormat(String format)
{
return _RegisterClipboardFormat(format);
}
https://github.com/ikvm-revived/ikvm/blob/master/openjdk/sun/awt/IkvmDataTransferer.java#L95
What I'm wondering is which local variable the error message is referring to? Might be something added implicitly or might have to do with String in Java vs. string in C#? OTOH that file is clearly named .java.
Didn't find much about the error message in general, only the following two links seems to be more interesting:
Variables having same name but different type
Why doesn't C# allow me to use the same variable name in different scopes?
So I'm currently even unsure where the message comes from, Visual Studio/C# directly or IKVM during running code during building Release-mode. I strongly suspect the error is coming from Visual Studio/C#, though.
Searching for the function itself doesn't reveal much of help as well:
Sorry, AWT is not a supported part of IKVM.
https://sourceforge.net/p/ikvm/bugs/225/
Others seemed to have the same problem, because CN1 simply disabled that code entirely in their fork of IKVM:
//#DllImportAttribute.Annotation(value = "user32.dll", EntryPoint = "RegisterClipboardFormat")
//private native static int _RegisterClipboardFormat(String format);
#cli.System.Security.SecuritySafeCriticalAttribute.Annotation
private static int RegisterClipboardFormat(String format)
{
throw new Error("Not implemented");
//return _RegisterClipboardFormat(format);
}
https://github.com/ams-ts-ikvm/cn1-ikvm-uwp/blob/master/openjdk/sun/awt/IkvmDataTransferer.java#L95
Any ideas? Thanks!

There seems to be a workaround by not changing any code at all: The settings of the Release-build contain a checkbox if to use the .NET native toolbox for the build, which is enabled by default. By disabling that the build succeeds without any code change and is as fast as the Debug-build again. Before changing that, the Release-build took a lot longer as well.
Don't know what that means regarding actually calling native code, if that fails or not, because my app doesn't use those. I guess it would fail, depending on if it works in Debug or not. Additionally, I'm not sure if the Windows store accepts such a modified Release-build, but as UWP-apps aren't forced to use native code at all, I guess there's a good chance things are going to work.

Executable fails with weird exception

I am using ILMerge and Quartz.NET in a C# .NET 4.0 Windows Service application. The app runs fine without using ILMerge, but now that we're nearing shipping release, I wanted to combine all DLLs into a single executable.
Problem is, that ILMerge seems to work fine, but when I run the combined executable, it throws this exception:
Unhandled Exception: Quartz.SchedulerException: ThreadPool type 'Quartz.Simpl.SimpleThreadPool' could not be instantiated. ---> System.InvalidCastException: Unable to cast object of type 'Quartz.Simpl.SimpleThreadPool' to type 'Quartz.Spi.IThreadPool'.
at Quartz.Util.ObjectUtils.InstantiateType[T](Type type) in :line 0
at Quartz.Impl.StdSchedulerFactory.Instantiate() in :line 0
--- End of inner exception stack trace ---
at Quartz.Impl.StdSchedulerFactory.Instantiate() in :line 0
at Quartz.Impl.StdSchedulerFactory.GetScheduler() in :line 0
Does anyone have any idea why this is? I have been wasting over 4 hours already and I can't figure it out. If I don't combine with ILMerge, then everything runs fine (with the Quartz.dll and Common.Logging.dll in the same directory).
I'm sure someone must have tried packaging Quartz.net up like this before, any ideas?

Disclaimer: I don't know Quartz.NET at all, although I spent some time struggling with ILMerge. When I finally understood its limitations... I stopped using it.
ILMerge'd application tends to have problems with everything which contains the word "reflection".
I can guess (I've never used Quartz.NET) that some classes are resolved using reflection and driven by configuration files.
Class is not only identified by its name (with namespace) but also by assembly it is coming from (unfortunatelly it doesn't get displayed in exception message).
So, let's assume you had (before ILMerging) two assemblies A (for you Application) and Q (for Quartz.NET).
Assembly 'A' was referencing assembly 'Q' and was using a class 'Q:QClass' which was implementing 'Q:QIntf'.
After merging, those classes became 'A:QClass' and 'A:QIntf' (they were moved from assembly Q to A) and all the references in code has been replaced to use those (completely) new classes/interfaces, so "A:QClass" is implementing "A:QIntf" now.
But, it did not change any config files/embedded strings which may still reference "Q:QClass".
So when application is reading those not-updated config files it still loads "Q:QClass" (why it CAN find it is a different question, maybe you left assembly 'Q' in current folder or maybe it is in GAC - see 1).
Anyway, "Q:QClass" DOES NOT implement "A:QIntf", it still implements "Q:QIntf" even if they are binary identical - so you can't cast 'Q:QClass' to 'A:QIntf'.
The not-ideal-but-working solution is to "embed" assemblies instead of "merging" them. I wrote a open-source tool which does it (embedding instead of merging) but it is not related to this question. So if you decide to embed just ask me.
You can test it by removing (hiding, whatever works for you) every single instance of Q.dll on your PC. If I'm right, the exception should say now 'FileNotFound'.

You could try creating your own ISchedulerFactory and avoid using reflection to load all of your types.
The StdSchedulerFactory uses this code to creat a threadpool. It's where your error is happening and would be the place to start looking at making changes:
Type tpType = loadHelper.LoadType(cfg.GetStringProperty(PropertyThreadPoolType)) ?? typeof(SimpleThreadPool);
try
{
tp = ObjectUtils.InstantiateType<IThreadPool>(tpType);
}
catch (Exception e)
{
initException = new SchedulerException("ThreadPool type '{0}' could not be instantiated.".FormatInvariant(tpType), e);
throw initException;
}
The ObjectUtils.InstantiateType method that is called is this one, and the last line is the one throwing your exception:
public static T InstantiateType<T>(Type type)
{
if (type == null)
{
throw new ArgumentNullException("type", "Cannot instantiate null");
}
ConstructorInfo ci = type.GetConstructor(Type.EmptyTypes);
if (ci == null)
{
throw new ArgumentException("Cannot instantiate type which has no empty constructor", type.Name);
}
return (T) ci.Invoke(new object[0]);
}
Right after this section in the factory, datasources are loaded using the same pattern and then the jobs themselves are also loaded dynamically which means you'd also have to write your own JobFactory. Since Quartz.Net loads a bunch of bits and pieces dynamically at runtime going down this road means you might end up rewriting a fair amount of things.

Is it possible to use Gephi compiled with IKVM in a website?

I'm currently trying to load and use the Gephi Toolkit from within a .Net 4 C# website.
I have a version of the toolkit jar file compiled against the IKVM virtual machine, which works as expected from a command line application using the following code:
var controller = (ProjectController)Lookup.getDefault().lookup(typeof(ProjectController));
controller.closeCurrentProject();
controller.newProject();
var project = controller.getCurrentProject();
var workspace = controller.getCurrentWorkspace();
The three instances are correctly instantiated in a form similar to org.gephi.project.impl.ProjectControllerImpl#8ddb93.
If however I run the exact same code, with the exact same using statements & references, the very first line loading the ProjectController instance returns null.
I have tried a couple of solutions
Firstly, I have tried ignoring the Lookup.getDefault().lookup(type) call, instead trying to create my own instances:
var controller = new ProjectControllerImpl();
controller.closeCurrentProject();
controller.newProject();
var project = controller.getCurrentProject();
var workspace = controller.getCurrentWorkspace();
This fails at the line controller.newProject();, I think because internally (using reflector) the same Lookup.getDefault().lookup(type) is used in a constructor, returns null and then throws an exception.
Secondly, from here: Lookup in Jython (and Gephi) I have tried to set the %CLASSPATH% to the location of both the toolkit JAR and DLL files.
Is there a reason why the Lookup.getDefault().lookup(type) would not work in a web environment? I'm not a Java developer, so I am a bit out of my depth with the Java side of this.
I would have thought it possible to create all of the instances myself, but haven't been able to find a way to do so.
I also cannot find a way of seeing why the ProjectController load returned null. No exception is thrown, and unless I'm being very dumb, there doesn't appear to be a method to see the result of the attempted load.
Update - Answer
Based on the answer from Jeroen Frijters, I resolved the issue like this:
public class Global : System.Web.HttpApplication
{
public Global()
{
var assembly = Assembly.LoadFrom(Path.Combine(root, "gephi-toolkit.dll"));
var acl = new AssemblyClassLoader(assembly);
java.lang.Thread.currentThread().setContextClassLoader(new MySystemClassLoader(acl));
}
}
internal class MySystemClassLoader : ClassLoader
{
public MySystemClassLoader(ClassLoader parent)
: base(new AppDomainAssemblyClassLoader(typeof(MySystemClassLoader).Assembly))
{ }
}
The code ikvm.runtime.Startup.addBootClassPathAssemby() didn't seem to work for me, but from the provided link, I was able to find a solution that seems to work in all instances.

This is a Java class loader issue. In a command line app your main executable functions as the system class loader and knows how to load assembly dependencies, but in a web process there is no main executable so that system class loader doesn't know how to load anything useful.
One of the solutions is to call ikvm.runtime.Startup.addBootClassPathAssemby() to add the relevant assemblies to the boot class loader.
For more on IKVM class loading issues see http://sourceforge.net/apps/mediawiki/ikvm/index.php?title=ClassLoader

Why do 'requires' statements fail when loading (iron)ruby script via a C# program?

IronRuby and VS2010 noob question:
I'm trying to do a spike to test the feasibility of interop between a C# project and an existing RubyGem rather than re-invent that particular wheel in .net. I've downloaded and installed IronRuby and the RubyGems package, as well as the gem I'd ultimately like to use.
Running .rb files or working in the iirb Ruby console is without problems. I can load the both the RubyGems package, and the gem itself and use it, so, at least for that use case, my environment is set up correctly.
However, when I try to do the same sort of thing from within a C# (4.0) console app, it complains about the very first line:
require 'RubyGems'
With the error:
no such file to load -- rubygems
My Console app looks like this:
using System;
using IronRuby;
namespace RubyInteropSpike
{
class Program
{
static void Main(string[] args)
{
var runtime = Ruby.CreateRuntime();
var scope = runtime.ExecuteFile("test.rb");
Console.ReadKey();
}
}
}
Removing the dependencies and just doing some basic self-contained Ruby stuff works fine, but including any kind of 'requires' statement seems to cause it to fail.
I'm hoping that I just need to pass some additional information (paths, etc) to the ruby runtime when I create it, and really hoping that this isn't some kind of limitation, because that would make me sad.

Short answer: Yes, this will work how you want it to.You need to use the engine's SetSearchPaths method to do what you wish.
A more complete example
(Assumes you loaded your IronRuby to C:\IronRubyRC2 as the root install dir)
var engine = IronRuby.Ruby.CreateEngine();
engine.SetSearchPaths(new[] {
#"C:\IronRubyRC2\Lib\ironruby",
#"C:\IronRubyRC2\Lib\ruby\1.8",
#"C:\IronRubyRC2\Lib\ruby\site_ruby\1.8"
});
engine.Execute("require 'rubygems'"); // without SetSearchPaths, you get a LoadError
/*
engine.Execute("require 'restclient'"); // install through igem, then check with igem list
engine.Execute("puts RestClient.get('http://localhost/').body");
*/
Console.ReadKey();