java - 如何创建具有扩展另一个类并实现接口(interface)的类型参数的基本适配器？

Question

我看到了 answer对于这个问题，

Java: how to create a generic class that requires a data type which extends a class and implements an interface?

所以我尝试为 recyclerview 创建一个基本适配器。这是基本适配器的完整代码:

class BaseAdapter<T extends SugarRecord & ModelInterface> extends RecyclerView.Adapter<BaseAdapter.ViewHolder> {

    protected SparseArray<T> modelSparseArray;
    protected Context context;

    private int backgroundResource;



    public BaseAdapter(SparseArray<T> modelSparseArray, Context context) {
        this.modelSparseArray = modelSparseArray;
        this.context = context;
        setupBackgroundResource(context);
    }

    private void setupBackgroundResource(Context context){
        TypedValue typedValue = new TypedValue();
        context.getTheme().resolveAttribute(R.attr.selectableItemBackground, typedValue, true);
        backgroundResource = typedValue.resourceId;
    }

    public class ViewHolder extends RecyclerView.ViewHolder{

        @Bind(R.id.done_indicator)
        CheckBox doneIndicator;

        @Bind(R.id.title)
        TextView title;

        View view;

        public ViewHolder(View itemView) {
            super(itemView);
            ButterKnife.bind(this, itemView);
            view = itemView;
        }
    }

    public void addModel(T model){
        int key = model.getId().intValue();
        int index = modelSparseArray.indexOfKey(key);
        modelSparseArray.append(key, model);
        if(key < 0)
            notifyItemInserted(modelSparseArray.size());
        else
            notifyItemChanged(index);
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.row_layout, parent, false);
        view.setBackgroundResource(backgroundResource);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, final int position) {
        final T model = modelSparseArray.valueAt(position);
        holder.title.setText(model.getTitle());
        holder.doneIndicator.setChecked(model.isDone());
        holder.doneIndicator.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                model.setDone(isChecked);
                model.save();
            }
        });
    }



    @Override
    public int getItemCount() {
        return modelSparseArray.size();
    }
}

这question几乎与我问的完全一样，但是，该问题的 OP 使用 pastebin 给出了问题的答案，不幸的是，该链接不再有效。

错误是:

Error:(24, 1) error: BaseAdapter is not abstract and does not override abstract method onBindViewHolder(BaseAdapter.ViewHolder,int) in Adapter
Error:(80, 5) error: method does not override or implement a method from a supertype

第一个错误指向类声明的开始，第二个错误指​​向onBindViewHolder上面的Override

Answer 1

所以我一发布问题就发现了答案，我会发布这个以防有人需要答案:

更改 RecyclerView.Adapter<BaseAdapter.ViewHolder>至 RecyclerView.Adapter<BaseAdapter<T>.ViewHolder>

我最初创建的基本适配器没有类型参数，所以它可以与 RecyclerView.Adapter<BaseAdapter.ViewHolder> 一起使用, 但在添加类型参数后，我还需要添加 <T> .

另一个解决方案是制作内部 ViewHolder正如@chRyNaN 建议的那样是静态的。