未选中对作为原始类型ListAdapter成员的submitList（List）的调用

Question

我一直在复制向日葵android架构最佳实践应用程序，到目前为止速度很慢但很成功，虽然我的代码正常工作，但它显示了一条未经检查的消息，所以我运行了它要求的命令，它说：

[unchecked]未选中对作为原始类型ListAdapter成员的submitList（List）的调用，其中T是类型变量：T扩展类ListAdapper中声明的对象

这可能是不重要的，但它是烦人的我，一个我用作参考从来没有任何

我的片段：

public class NewsFeedFragment extends Fragment {

    private PinViewModel viewModel;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        FragmentNewsFeedBinding binding = FragmentNewsFeedBinding.inflate(inflater, container, false);
        PinViewModelFactory factory = InjectorUtils.providePinListViewModelFactory(getContext());
        ListAdapter adapter = new PinListAdapter();
        binding.pinList.setAdapter(adapter);
        this.viewModel = ViewModelProviders.of(this, factory).get(PinViewModel.class);
        subscribeUi(adapter);
        return binding.getRoot();
    }

    private void subscribeUi(ListAdapter adapter) {
        this.viewModel.pins.observe(getViewLifecycleOwner(), pins -> {
            if (pins != null) {
                adapter.submitList(pins);
            }
        });
    }
}

我的视图模型：

public class PinViewModel extends ViewModel {

    private PinRepository pinRepository;

    public LiveData<List<Pin>> pins;

    PinViewModel(@NonNull PinRepository pinRepository) {
        this.pinRepository = pinRepository;
        this.pins = this.pinRepository.getPins();
    }
}

我的适配器:

public class PinListAdapter extends ListAdapter<Pin, PinListAdapter.ViewHolder>{

    public PinListAdapter() {
        super(new PinDiffCallback());
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        return new ViewHolder(ListItemPinBinding.inflate(
                LayoutInflater.from(parent.getContext()), parent, false));
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        Pin pin = getItem(position);
        holder.bind(pin);
        holder.itemView.setTag(pin);
    }

    static class ViewHolder extends RecyclerView.ViewHolder {
        private ListItemPinBinding binding;

        ViewHolder(@NonNull ListItemPinBinding binding) {
            super(binding.getRoot());
            this.binding = binding;
        }

        void bind(Pin item) {
            binding.setPin(item);
            binding.executePendingBindings();
        }
    }

    static class PinDiffCallback extends DiffUtil.ItemCallback<Pin> {

        @Override
        public boolean areItemsTheSame(@NonNull Pin oldItem, @NonNull Pin newItem) {
            return oldItem.getId() == (newItem.getId());
        }

        @Override
        public boolean areContentsTheSame(@NonNull Pin oldItem, @NonNull Pin newItem) {
            return oldItem == newItem;
        }
    }
}

Answer 1

这个例子是用Kotlin而不是Java编写的...

尚不清楚什么列表

if (pins != null && pins instanceof List<Pin>) {
    adapter.submitList(pins);
}

Answer 2

你在使用

ListAdapter adapter = new PinListAdapter();

这就是扔掉类型信息PinListAdapter。具体来说，ListAdapter

您可以将适配器更改为＜code＞PinListAdapter＜/code＞并获得所需的类型信息。