前言

RecycleView每次使用都要創建 Adapter 的類文件，而Adapter每次都基本差不錯，因此可以對RecycleAdapter進行封裝，這樣就不用每次創建Adapter的類文件，提升開發效率。

使用封裝好的RecycleAdapter例子：

  BaseRecycleAdapter<String, MyViewHolder> recycleAdapter = new BaseRecycleAdapter<>(generatorData(20), R.layout.item_recycle);
        recycleAdapter
                .setFactory(new IViewHolderFactory<MyViewHolder>() {
                    @Override
                    public MyViewHolder generatorViewHolder(View view, BaseViewHolder.OnItemClickListener onItemClickListener) {
                        return new MyViewHolder(view, onItemClickListener);
                    }
                })
                .setOnItemClickListener(new BaseViewHolder.OnItemClickListener() {
                    @Override
                    public void onItemClicked(View v, int position) {
                        Toast.makeText(MainActivity.this,String.valueOf(position),Toast.LENGTH_LONG).show();
                    }
                });
        mMainBing.rvContent.setAdapter(recycleAdapter);

class MyViewHolder extends BaseViewHolder<String> {
    ItemRecycleBinding item;

    public MyViewHolder(View itemView, OnItemClickListener onItemClickedListener) {
        super(itemView, onItemClickedListener);
        item = DataBindingUtil.bind(itemView);
    }

    @Override
    public void setData(String s) {
        item.setPosition(s);
    }
}

這樣對RecycleView的數據填充便完成了，整個過程中沒有創建新的Adapter類文件，如果使用Lambda 代碼還可以進一步簡化。

Adapter基本封裝

ReccycleAdapter

public class BaseRecycleAdapter<D,V extends BaseViewHolder<D>> extends RecyclerView.Adapter<V> {
    private List<D> mDatas;
    private IViewHolderFactory<V> mFactory;
    private int mLayoutId;
    private BaseViewHolder.OnItemClickListener mOnItemClickedListener;
    public BaseRecycleAdapter(List<D> datas,int layoutId){
        this.mDatas=datas;
        this.mLayoutId=layoutId;
    }
    @Override
    public V onCreateViewHolder(ViewGroup parent, int viewType) {
        View view= LayoutInflater.from(parent.getContext()).inflate(mLayoutId,parent,false);

        return mFactory.generatorViewHolder(view,mOnItemClickedListener);
    }

    @Override
    public void onBindViewHolder(V holder, int position) {
        holder.setData(mDatas.get(position));
    }

    @Override
    public int getItemCount() {
        return mDatas==null?0:mDatas.size();
    }

    public BaseRecycleAdapter setOnItemClickListener(BaseViewHolder.OnItemClickListener onItemClickListener){
        this.mOnItemClickedListener =onItemClickListener;
        return this;
    }
    public BaseRecycleAdapter setFactory(IViewHolderFactory<V> factory){
        this.mFactory=factory;
        return this;
    }
    public void updateData(final List<D> newDatas){
        DiffUtil.DiffResult  result=DiffUtil.calculateDiff(new DiffUtil.Callback() {
            @Override
            public int getOldListSize() {
                return mDatas.size();
            }

            @Override
            public int getNewListSize() {
                return newDatas.size();
            }

            @Override
            public boolean areItemsTheSame(int oldItemPosition, int newItemPosition) {
                return mDatas.get(oldItemPosition)==newDatas.get(newItemPosition);
            }

            @Override
            public boolean areContentsTheSame(int oldItemPosition, int newItemPosition) {
                return mDatas.get(oldItemPosition).equals(newDatas.get(newItemPosition));
            }
        },true);
        result.dispatchUpdatesTo(this);
    }


}

ViewHolder

public abstract class BaseViewHolder<D> extends RecyclerView.ViewHolder {
    public BaseViewHolder(View itemView, final OnItemClickListener onItemClickedListener){
        super(itemView);
        if(onItemClickedListener!=null){
            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    onItemClickedListener.onItemClicked(v,getAdapterPosition());
                }
            });
        }
    }
    public abstract void setData(D d);

    public interface OnItemClickListener{
        void onItemClicked(View v,int position);
    }

ViewHolderFactory

public interface IViewHolderFactory<T> {
        T generatorViewHolder(View view, BaseViewHolder.OnItemClickListener onItemClickListener);
}

添加Header(添加footer與此相同)

public class HeaderAdapter  extends RecyclerView.Adapter{
    private RecyclerView.Adapter mAdapter;
    private List<View> mHeaders;

    public HeaderAdapter(List<View> headers){
        this.mHeaders=headers;
    }
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        if(viewType<mHeaders.size()){
            return new CommonViewHolder(mHeaders.get(viewType));
        }
        else {
            return mAdapter.onCreateViewHolder(parent, viewType-mHeaders.size());
        }
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        mAdapter.onBindViewHolder(holder,position);
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position, List payloads) {
        mAdapter.onBindViewHolder(holder, position, payloads);
    }

    @Override
    public int getItemViewType(int position) {
        if(position>=mHeaders.size()){
            return mHeaders.size()+mAdapter.getItemViewType(position);
        }else{
            return position;
        }

    }
........
}

代碼已上傳到GitHub：https://github.com/guhongya/base-library