从使用反射获得的RecyclerView调用方法

Question

I need to access the methods of a RecyclerView that is created using a third party library. What I'm doing is to get hold of the RecyclerView View using the findViewById:

ViewGroup mainView = mainActivity.getWindow().getDecorView().findViewById(android.R.id.content);
    if(feedView == null){
        Object okStreamRecyclerView =  mainView.findViewById(NEWSFEED_RECYCLER_ID);
        feedView = (okStreamRecyclerView.getClass().getSuperclass()).getSuperclass();
        scrollToTop(feedView);
    }

At this point feedView.getSimpleName results in RecyclerView . Then I'm trying to scroll this RecyclerView to the top using:

private void scrollToTop(Class feedView) {
        log("THE VIEW IS OF TYPE: "+feedView.getName()); // androidx.recyclerview.widget.RecyclerView
        try {
            Method method = feedView.getMethod("getLayoutManager");
            method.setAccessible(true);
            LinearLayoutManager layoutManager = (LinearLayoutManager) method.invoke(feedView);
            layoutManager.scrollToPositionWithOffset(0, 0);
        } catch (NoSuchMethodException e) {
           log("NO SUCH METHOD EXCEPTION",e);
        } catch (IllegalAccessException e) {
            log("ILLEGAL ACCESS EXCEPTION",e);
        } catch (InvocationTargetException e) {
            log("INVOCATION TARGET EXCEPTION",e);
        }
    }

but for some reason I get the error bellow:

IllegalArgumentException: Expected receiver of type androidx.recyclerview.widget.RecyclerView, but got java.lang.Class<androidx.recyclerview.widget.RecyclerView>

How can I convert the Class to the expected RecyclerView ? Is there any other way to get hold of this view ?

Answer 1

Thanks to @CommonsWare hint I managed to invoke the ScrollToPosition method using reflection. Here is the working code in my specific case, it might be easier in some other scenario:

View okStreamRecyclerView = null;
            try {
                okStreamRecyclerView = mainView.findViewById(NEWSFEED_RECYCLER_ID);
                feedView = (okStreamRecyclerView.getClass().getSuperclass()).getSuperclass();
                Method method = feedView.getMethod("getLayoutManager");
                method.setAccessible(true);
                LinearLayoutManager layoutManager = (LinearLayoutManager) method.invoke(okStreamRecyclerView);
                Class llm = layoutManager.getClass().getSuperclass();
                Method m2 = llm.getMethod("scrollToPositionWithOffset",int.class, int.class);
                m2.setAccessible(true);
                m2.invoke(layoutManager,0,0);
            } catch (ClassCastException e){
                log("AN EXECPTON OCCURED WHILE FETCHING VIEW",e);
            } catch (NoSuchMethodException e) {
                e.printStackTrace();
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            } catch (InvocationTargetException e) {
                e.printStackTrace();
            }