解决方案如下：
public class BookmarkPlugin implements IPluginModule {
private boolean b = false;
@Override
public Drawable obtainDrawable(Context context) {
int resId = b ? R.drawable.rc_complete_hover : R.drawable.rc_complete;
return context.getResources().getDrawable(resId);
}
@Override
public String obtainTitle(Context context) {
return b ? "已收藏" : "收藏";
}
@Override
public void onClick(Fragment fragment, RongExtension rongExtension) {
b = !b;
ViewPager viewPager = rongExtension.findViewById(R.id.rc_view_pager);
GridView gridView = (GridView) viewPager.getChildAt(0);
((BaseAdapter) gridView.getAdapter()).notifyDataSetChanged();
}
@Override
public void onActivityResult(int i, int i1, Intent intent) {
}
}