Accessing COM Interface with JNA

Question

I'm trying to access the IDesktopWallpaper interface with JNA, but I've hit a wall.

I went through ShOljIdl_core.idl (from Windows 10 SDK) and discovered the GUID of the interface as follows

// IDesktopWallpaper
[
    uuid(B92B56A9-8B55-4E14-9A89-0199BBB6F93B),
    object
]

and the GUID of the concrete class that implements the interface

// CLSID_DesktopWallpaper
[uuid(C2CF3110-460E-4fc1-B9D0-8A1C0C9CC4BD)] coclass DesktopWallpaper { interface IDesktopWallpaper; }

So I followed the official example in the JDA github and wrote the following

@ComObject(clsId="{C2CF3110-460E-4fc1-B9D0-8A1C0C9CC4BD}")
public interface DesktopWallpaper extends IUnknown{


}

and in Main

Ole32.INSTANCE.CoInitializeEx(Pointer.NULL, Ole32.COINIT_MULTITHREADED);
try {
    Factory factory = new Factory();
    try {
        DesktopWallpaper dw = factory.createObject(DesktopWallpaper.class);
    } finally {
        factory.disposeAll();
        factory.getComThread().terminate(1 * 1000);
    }

} finally {
    Ole32.INSTANCE.CoUninitialize();
}

But the factory.createObject(DesktopWallpaper.class) throws No such interface supported(HRESULT: 80004002) (puArgErr=)and I don't know how to get around this or why it is happening.

Can any experts enlighten me on what's happening? (I am a complete noob) I will provide any further info that's necessary. Can JNA achieve what I want or do I have to use something else like Com4j?

Accessing COM Interface with JNA

1 Answers