自帶頭部，底部，和空布局的recycleView.Adapter基類封裝相關(guān)說(shuō)明:

1.適用于多種類型的條目類型（目前支持頭部，底部，和空布局，其他條目布局需要自己擴(kuò)展）
2.支持空頁(yè)面展示和自定義空布局
3.支持頭部和底部的添加和自定義頭部和底部布局

下面對(duì)關(guān)鍵代碼進(jìn)行分析：

重寫getItemViewType(int position) 方法，根據(jù)不同的條目返回對(duì)應(yīng)的布局類型在這里我定義了四種布局類型：默認(rèn)條目類型，頭部，底部，和空布局

@Override
public int getItemViewType(int position) {
    int size = 0;
    boolean isEmpty = null == data || data.isEmpty();
    if (isShowHeader) ++size;
    if (isShowFooter) ++size;
    if (isShowHeader && !isEmpty && position == 0) return TYPE_HEADER;
    if (isShowFooter && !isEmpty && (data.size()-1+size == position)) return TYPE_FOOTER;
    if (isShowEmpty && isEmpty) return TYPE_EMPTY;
    return super.getItemViewType(position);
}

重寫 getItemCount()方法，計(jì)算出需要的 item 數(shù)量，這里我在這里我通過(guò)判斷data數(shù)據(jù)源的數(shù)據(jù)來(lái)判斷當(dāng)數(shù)據(jù)為空時(shí)不顯示頭部和底部，有需要顯示的可以修改這部分代碼

@Override
public int getItemCount() {
    int size = 0;
    boolean isEmpty = null == data || data.isEmpty();
    if (isShowHeader && !isEmpty) ++size;
    if (isShowFooter && !isEmpty) ++size;
    if (isShowEmpty && isEmpty) return 1;
    return data.size()+size;
}

重寫onCreateViewHolder(@NonNull ViewGroup parent, int viewType) ， 根據(jù)viewType來(lái)判斷創(chuàng)建不同的ViewHolder類型，這里頭部，底部和空頁(yè)面都通過(guò)了方法返回的方式來(lái)創(chuàng)建View,目的是為了方便自定義布局的使用（注意：頭部和底部要放到空頁(yè)面的前面判斷，后面會(huì)有說(shuō)明）

@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    switch (viewType) {
        case TYPE_HEADER:
            return new ViewHolderHeader<>(parent,layoutResIdHeader());
        case TYPE_FOOTER:
            return new ViewHolderFooter<>(parent,layoutResIdFooter());
        case TYPE_EMPTY:
            return new ViewHolderEmpty<>(parent,layoutResIdEmpty());
        default:
            return new ViewHolder<D>(parent,layoutResId());
    }
}

重寫onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) 方法，在該方法中判斷布局類型，onBindView 是通用默認(rèn)的類型，onBindViews適用于頭部，底部和空頁(yè)面布局，大家可以根據(jù)自己的需要去改。當(dāng)然如果有頭部布局顯示，不要忘記position要減去1。頭部，底部的viewHolder 要在空布局的viewHolder之前判斷，下面我會(huì)貼出原因：

@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
    if (holder instanceof ViewHolder) {
        int len = isShowHeader?position-1:position;
        onBindViewHolders(((ViewHolder<D>)holder).binding,len);
        checkedListener(((ViewHolder<D>)holder).binding,len);
    } else if (holder instanceof ViewHolderHeader) {
        onBindView(((ViewHolderHeader) holder).binding);
    } else if (holder instanceof ViewHolderFooter) {
        onBindView(((ViewHolderFooter) holder).binding);
    } else if (holder instanceof ViewHolderEmpty){
        onBindView(((ViewHolderEmpty) holder).binding);
    }
//        holder.binding.executePendingBindings();
}
    //原因:頭部和尾部都繼承了空布局的ViewHodler
public static class ViewHolderEmpty<E extends ViewDataBinding> extends RecyclerView.ViewHolder{
    public E binding;
    public ViewHolderEmpty(ViewGroup parent,@LayoutRes int resId) {
        super(DataBindingUtil.inflate(LayoutInflater.from(parent.getContext()),resId,parent,false).getRoot());
        binding = DataBindingUtil.getBinding(this.itemView);
    }
 }

public static class ViewHolderHeader<E extends ViewDataBinding> extends ViewHolderEmpty<E> {
    public ViewHolderHeader(ViewGroup parent, int resId) {
        super(parent, resId);
    }
}

public static class ViewHolderFooter<E extends ViewDataBinding> extends ViewHolderEmpty<E> {
    public ViewHolderFooter(ViewGroup parent, int resId) {
        super(parent, resId);
    }
}

針對(duì)實(shí)現(xiàn)GridView效果的頭部、尾部和空布局的適配問(wèn)題，例如使用了兩列，代碼如下：

    GridLayoutManager layoutManager =  new GridLayoutManager(getApplication(),2, LinearLayoutManager.VERTICAL,false);
    layoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
        @Override
        public int getSpanSize(int position) {
            int type = adapter.getItemViewType(position);
            if (type == BaseRecycleAdapter.TYPE_HEADER
                 || type == BaseRecycleAdapter.TYPE_FOOTER 
                 || type == BaseRecycleAdapter.TYPE_EMPTY) return 2;
            return 1;
        }
    });

最后附上完整的代碼，希望對(duì)大家有幫助，如果有不足的地方歡迎大家指正，謝謝。

public abstract class BaseRecycleAdapter<T,D extends ViewDataBinding> extends RecyclerView.Adapter<RecyclerView.ViewHolder>{

protected List<T> data;
protected OnItemClickListener onItemClickListener;
private boolean isUseDefaultListener = true;

private boolean isShowHeader = false;
private boolean isShowFooter = false;
private boolean isShowEmpty = true;

public BaseRecycleAdapter(List<T> data, boolean isUseDefaultListener,boolean isShowHeader ,boolean isShowFooter,boolean isShowEmpty) {
    this(data,isShowHeader,isShowFooter,isShowEmpty);
    this.isUseDefaultListener = isUseDefaultListener;
}

public BaseRecycleAdapter(List<T> data ,boolean isShowHeader ,boolean isShowFooter,boolean isShowEmpty) {
    this(data,true);
    this.isShowHeader = isShowHeader;
    this.isShowFooter = isShowFooter;
    this.isShowEmpty = isShowEmpty;
}

public BaseRecycleAdapter(List<T> data, boolean isUseDefaultListener) {
    this(data);
    this.isUseDefaultListener = isUseDefaultListener;
}

public BaseRecycleAdapter(List<T> data) {
    this.data = data;
}

private static final int TYPE_EMPTY = 1;
private static final int TYPE_HEADER = 2;
private static final int TYPE_FOOTER = 3;
//通用條目
public abstract @LayoutRes
int layoutResId();

//空布局條目
public @LayoutRes int layoutResIdEmpty(){
    return R.layout.view_base_empty;
}

public @LayoutRes int layoutResIdHeader(){
    return layoutResIdEmpty();
}

public @LayoutRes int layoutResIdFooter(){
    return layoutResIdEmpty();
}

/**
 * 通用item
 * @param binding   布局
 * @param position  條目索引
 */
public abstract void onBindViewHolders(D binding, int position);

/**
 * 頭部尾部和空布局
 * @param binding 布局
 */
public void onBindView(ViewDataBinding binding) {}

public void addOnItemClickListener(OnItemClickListener onItemClickListener) {
    this.onItemClickListener = onItemClickListener;
}

@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    switch (viewType) {
        case TYPE_HEADER:
            return new ViewHolderHeader<>(parent,layoutResIdHeader());
        case TYPE_FOOTER:
            return new ViewHolderFooter<>(parent,layoutResIdFooter());
        case TYPE_EMPTY:
            return new ViewHolderEmpty<>(parent,layoutResIdEmpty());
        default:
            return new ViewHolder<D>(parent,layoutResId());
    }
}

@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
    if (holder instanceof ViewHolder) {
        int len = isShowHeader?position-1:position;
        onBindViewHolders(((ViewHolder<D>)holder).binding,len);
        checkedListener(((ViewHolder<D>)holder).binding,len);
    } else if (holder instanceof ViewHolderHeader) {
        onBindView(((ViewHolderHeader) holder).binding);
    } else if (holder instanceof ViewHolderFooter) {
        onBindView(((ViewHolderFooter) holder).binding);
    } else if (holder instanceof ViewHolderEmpty){
        onBindView(((ViewHolderEmpty) holder).binding);
    }
//        holder.binding.executePendingBindings();
}

protected void checkedListener(D binding,int position){
    if (isUseDefaultListener && null != data && data.size() > 0 && onItemClickListener != null) {
        binding.getRoot().setOnClickListener(view -> onItemClickListener.onClickListener(view,position));
    }
}

@Override
public int getItemCount() {
    int size = 0;
    boolean isEmpty = null == data || data.isEmpty();
    if (isShowHeader && !isEmpty) ++size;
    if (isShowFooter && !isEmpty) ++size;
    if (isShowEmpty && isEmpty) return 1;
    return data.size()+size;
}

@Override
public int getItemViewType(int position) {
    int size = 0;
    boolean isEmpty = null == data || data.isEmpty();
    if (isShowHeader) ++size;
    if (isShowFooter) ++size;
    if (isShowHeader && !isEmpty && position == 0) return TYPE_HEADER;
    if (isShowFooter && !isEmpty && (data.size()-1+size == position)) return TYPE_FOOTER;
    if (isShowEmpty && isEmpty) return TYPE_EMPTY;
    return super.getItemViewType(position);
}

public static class ViewHolder<D extends ViewDataBinding> extends RecyclerView.ViewHolder {
    public D binding;
    public ViewHolder(ViewGroup parent, @LayoutRes int resId) {
        super(DataBindingUtil.inflate(LayoutInflater.from(parent.getContext()),resId,parent,false).getRoot());
        binding = DataBindingUtil.getBinding(this.itemView);
    }
}

public static class ViewHolderEmpty<E extends ViewDataBinding> extends RecyclerView.ViewHolder{
    public E binding;
    public ViewHolderEmpty(ViewGroup parent,@LayoutRes int resId) {
        super(DataBindingUtil.inflate(LayoutInflater.from(parent.getContext()),resId,parent,false).getRoot());
        binding = DataBindingUtil.getBinding(this.itemView);
    }
}

public static class ViewHolderHeader<E extends ViewDataBinding> extends ViewHolderEmpty<E> {
    public ViewHolderHeader(ViewGroup parent, int resId) {
        super(parent, resId);
    }
}

public static class ViewHolderFooter<E extends ViewDataBinding> extends ViewHolderEmpty<E> {
    public ViewHolderFooter(ViewGroup parent, int resId) {
        super(parent, resId);
    }
}
}