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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.

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

Using Reflection to use a namespace on certain OSs

I'm creating a program that uses the CodeProject CoreAudioApi (pretty popular framework for manipulating audio), but the problem is the CoreAudioApi uses system calls that aren't available in any versions of Windows earlier than Vista. If I run a program with CoreAudioApi compiled with it (using a using statement as normal), the program will crash on anything earlier than Vista.
I've created this function to get the version number of the current environment:
win_version = Environment.OSVersion.Version.Major;
That returns the major version number I need. '6' is Vista/7, anything else is not, which is all I need to determine. Utilizing this, I need to determine whether or not to include the CoreAudioApi namespace if the OS is over or equal to '6'. From research, usings need to be compiled with the program, but I've also read about something called Reflection - which might be what I need.
Once I get the CoreAudioApi namespace using'd (sorry for the lack of terminology), the rest is easy. How can I do this?
TL;DR
I need some form of code that would effectively do this:
using System;
using System.Text;
//etc
if(currentWindowsVersion>=6) using CoreAudioApi;
Except control structures won't work outside of a class, and all namespaces are compiled with the program, not controlled individually.
Thanks!
EDIT: So far, I'm using this to load the CoreAudioApi namespace as a compiled assembly:
if(win_version>=6){
CoreAudioApi = Assembly.LoadFrom("CoreAudio.dll");
CoreAudioApi.GetLoadedModules();
CoreAudioApi.GetTypes();
MessageBox.Show("Loaded CoreAudioApi");
}
From here, what I need to do is actually use the types, and methods from the API. My code that works on Windows Vista/7 is this:
public static MMDeviceEnumerator devEnum;
public static MMDevice defaultDevice;
//later in a mute method:
defaultDevice.AudioEndpointVolume.Mute = true/false;
I don't even really need devEnum AFAIK, so really the only important lines are the last two (besides the comment).

I've just tried the following:
Create a new console application project
Add the CoreAudioApi project from CodeProject to the solution
Add a project reference to CoreAudioApi in my console app
Create the following classes:
interface IAudio { void SetVolume(float level); }
class XpAudio : IAudio {
public void SetVolume(float level) {
// I do nothing, but this is where your old-style code would go
}
}
class VistaAudio : IAudio {
public void SetVolume(float level) {
MMDeviceEnumerator devEnum = new MMDeviceEnumerator();
MMDevice defaultDevice = devEnum
.GetDefaultAudioEndpoint(EDataFlow.eRender, ERole.eMultimedia);
defaultDevice.AudioEndpointVolume.MasterVolumeLevel = level;
}
}
class Program {
static void Main(string[] args) {
IAudio setter = Environment.OSVersion.Version.Major >= 6
? (IAudio)new VistaAudio()
: (IAudio)new XpAudio();
float val = float.Parse(Console.ReadLine());
setter.SetVolume(val);
Console.ReadLine();
}
}
This runs on both my server (~ Windows 7) and local (Windows XP) machines. On my XP machine it'll happily take in a value and ignore it; on my server, it throws an exception, (presumably because I don't have a sound output). If I make my XP machine run the CoreAudioApi, I get an exception when I input a value, not before.
The question is, what are you doing differently to make your application break? Are you using CoreAudioApi code at startup?
EDIT: After seeing your edit, if you do this, you shouldn't need to mess about with Assembly.LoadFrom at all. The framework should dynamically load that assembly if (and only if) and when it needs to.

COREAUDIOAPI.dll does not work on XP or earlier, because they cant handle MMDEVICE API (Device Enumeration). I dont know about Vista.

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();

convert code snippet to C#

VS 2008
I have this code snippet I found on a VB website.
But for some reason I am having trouble converting it to C#.
My.Computer.Network.IsAvailable
Many thanks,

using System.Net.NetworkInformation;
internal class Program
{
private static void Main()
{
NetworkInterface.GetIsNetworkAvailable();
}
}

Yes, garethm is right, this class (Network) is from a VB.NET library - you need to reference the Microsoft.VisualBasic assembly if using in a C# project.
Microsoft.VisualBasic.Devices.Network n = new Microsoft.VisualBasic.Devices.Network();
if (n.IsAvailable)
{
// do stuff
}
Works for me - my network is available :).
As far as how Network relates to NetworkInterface class, it depends on what you want to do next. For instance, Network has such nice stuff as NetworkAvailabilityChanged event, and UploadFile method. On the other hand, NetworkInterface can give you a bunch of specific technical info such as speed or whether it supports multicast.
BTW, there is nothing undocumented about using a class from Microsoft.VisualBasic namespace - it's the core idea behind .NET that you can use classes from assemblies regardless of the language they were written in.

What I generally do is write a small app, then load then project in Reflector and disassemble it.
but you can use this class:
System.Net.NetworkInformation.NetworkChange.NetworkAddressChanged

Isn't the whole "My" thing from a VB library?

This appears to work. It's probably very undocumented usage though:
Microsoft.VisualBasic.Devices.Network net = new Microsoft.VisualBasic.Devices.Network();
if (net.IsAvailable)
{
Text = "Network is available";
}
else
{
Text = "Network unavailable";
}
Note that I needed to add a reference to Microsoft.VisualBasic to my project.