Re: [Ikvm-developers] Question about ikvmstub and .NET generics

[Jeroen F. <je...@su...>]

Hi,

Java doesn't support reified generics and I don't know of any way to reasonbly fake it, so ikvmstub doesn't export generic methods. You could write a small non-generic wrapper in C# that calls the generic method, or if there aren't very many methods, you could use .NET reflection (from Java) to call the Add method.

Here's an example of using a delegate to call a generic method:

import cli.System.AsyncCallback;
import cli.System.Activator;
import cli.System.Delegate;
import cli.System.IAsyncResult;
import cli.System.MulticastDelegate;
import cli.System.Type;
import cli.System.Collections.IList;
import ikvm.runtime.Util;

class GenericMethod
{
  public static final class AddDelegate extends MulticastDelegate
  {
    public AddDelegate(Method m) { }
    public native void Invoke(GenericMethod obj);
    public interface Method
    {
        void Invoke(GenericMethod obj);
    }
  }

  public static void main(String[] args)
  {
    IList list = (IList)Activator.CreateInstance(
      Type.GetType("System.Collections.Generic.List`1").
        MakeGenericType(Util.getInstanceTypeFromClass(GenericMethod.class))
    );
    AddDelegate add = (AddDelegate)Delegate.CreateDelegate(
      Util.getInstanceTypeFromClass(AddDelegate.class),
      list,
      "Add");
    add.Invoke(new GenericMethod());
    add.Invoke(new GenericMethod());
    add.Invoke(new GenericMethod());
    for (int i = 0; i < list.get_Count(); i++)
    {
      System.out.println(list.get_Item(i));
    }
  }
}

Regards,
Jeroen

> -----Original Message-----
> From: Gluck, Janice [mailto:Jan...@ph...]
> Sent: Tuesday, September 07, 2010 10:05 PM
> To: ikv...@li...
> Subject: [Ikvm-developers] Question about ikvmstub and .NET generics
> 
> Hello,
> 
> I am new to IKVM.NET.   I am a java developer....
> 
> I need to write code that interacts with .NET assemblies from a third
> party vendor (so the .NET code can't be changed)..
> 
> I ran ikvmstub against the exe provided by the vendor and java stub
> classes were generated but for the key class I need to use
> 
> Any methods that had generics as parameters were not included in the
> java stub class:
> 
> For example:
> 
> In the DataStore class (.net) - per the vendor's doco there should be a
> method:
> 
> Add<(Of <(T>)>)(T)
> <mk:@MSITStore:C:\geotabinfo\CheckmateSdk.chm::/html/cdab33d4-a27b-67df-
> 2c89-ab08a5e2d4b8.htm>
> 
> But when I look in the generated DataStore java class, there is no Add
> method of any kind.   (I decompiled the stub class)...
> 
> Is it possible to get these methods to generate using ikvmstub or is
> there another workaround I can try?
> 
> I need to be able to access the .NET code from java....and I can't change
> the .net side of things...
> 
> Thank you for your help!
> 
> Janice