RecyclerView添加头部和底部

Demo地址：http://download.csdn.net/detail/baopengjian/9885502

#1 原理：

RecyclerView没有暴露添加head和foot的方法，需要自行封装

利用不同的type添加ViewHolder即可，注意插入的位置和当LayoutManger为GridLayoutManger时，head和foot要独立的占一行。

#2 效果图：

#3 代码：

1）定义适配器（其他地方和普通使用时一样，主要是在适配器上做修改）：

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyHolder> {

private RecyclerView mRecyclerView;

private List<String> data = new ArrayList<>();

private Context mContext;

private View VIEW_FOOTER;

private View VIEW_HEADER;

//Type

private int TYPE_NORMAL = 1000;

private int TYPE_HEADER = 1001;

private int TYPE_FOOTER = 1002;

public MyAdapter(List<String> data, Context mContext){

this.data = data;

this.mContext = mContext;

}

@Override

public MyHolder onCreateViewHolder(ViewGroup parent, int viewType) {

if (viewType == TYPE_FOOTER) {

return new MyHolder(VIEW_FOOTER);

} else if (viewType == TYPE_HEADER) {

return new MyHolder(VIEW_HEADER);

} else {

return new MyHolder(getLayout(R.layout.item_list_layout));

}

}

@Override

public void onBindViewHolder(MyHolder holder, int position) {

if (!isHeaderView(position) && !isFooterView(position)) {

if (haveHeaderView()) position--;

TextView content = holder.itemView.findViewById(R.id.item_content);

TextView time = holder.itemView.findViewById(R.id.item_time);

content.setText(data.get(position));

time.setText("2016-1-1");

}

}

@Override

public int getItemCount() {

int count = (data == null ? 0 : data.size());

if (VIEW_FOOTER != null) {

count++;

}

if (VIEW_HEADER != null) {

count++;

}

return count;

}

@Override

public int getItemViewType(int position) {

if (isHeaderView(position)) {

return TYPE_HEADER;

} else if (isFooterView(position)) {

return TYPE_FOOTER;

} else {

return TYPE_NORMAL;

}

}

@Override

public void onAttachedToRecyclerView(RecyclerView recyclerView) {

try {

if (mRecyclerView == null && mRecyclerView != recyclerView) {

mRecyclerView = recyclerView;

}

ifGridLayoutManager();

} catch (Exception e) {

e.printStackTrace();

}

}

private View getLayout(int layoutId) {

return LayoutInflater.from(mContext).inflate(layoutId, null);

}

public void addHeaderView(View headerView) {

if (haveHeaderView()) {

throw new IllegalStateException("hearview has already exists!");

} else {

//避免出现宽度自适应

ViewGroup.LayoutParams params = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);

headerView.setLayoutParams(params);

VIEW_HEADER = headerView;

ifGridLayoutManager();

notifyItemInserted(0);

}

}

public void addFooterView(View footerView) {

if (haveFooterView()) {

throw new IllegalStateException("footerView has already exists!");

} else {

ViewGroup.LayoutParams params = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);

footerView.setLayoutParams(params);

VIEW_FOOTER = footerView;

ifGridLayoutManager();

notifyItemInserted(getItemCount() - 1);

}

}

private void ifGridLayoutManager() {

if (mRecyclerView == null) return;

final RecyclerView.LayoutManager layoutManager = mRecyclerView.getLayoutManager();

if (layoutManager instanceof GridLayoutManager) {

((GridLayoutManager) layoutManager).setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {

@Override

public int getSpanSize(int position) {

return (isHeaderView(position) || isFooterView(position)) ?

((GridLayoutManager) layoutManager).getSpanCount() :

1;

}

});

}

}

private boolean haveHeaderView() {

return VIEW_HEADER != null;

}

public boolean haveFooterView() {

return VIEW_FOOTER != null;

}

private boolean isHeaderView(int position) {

return haveHeaderView() && position == 0;

}

private boolean isFooterView(int position) {

return haveFooterView() && position == getItemCount() - 1;

}

public static class MyHolder extends RecyclerView.ViewHolder {

public MyHolder(View itemView) {

super(itemView);

}

}

}

（2）使用Adapter

public void linearLayout(View view){

LinearLayoutManager manager = new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false);

rv.setLayoutManager(manager);

MyAdapter adapter = new MyAdapter(mDatas,this);

TextView tv = new TextView(this);

tv.setText("This is head");

tv.setTextSize(TypedValue.COMPLEX_UNIT_DIP,32);

TextView foot = new TextView(this);

foot.setText("This is foot");

foot.setTextSize(TypedValue.COMPLEX_UNIT_DIP,32);

adapter.addHeaderView(tv);

adapter.addFooterView(foot);

rv.setAdapter(adapter);

}

public void gridLayout(View view){

GridLayoutManager manager = new GridLayoutManager(this,3);

rv.setLayoutManager(manager);

MyAdapter adapter = new MyAdapter(mDatas,this);

TextView tv = new TextView(this);

tv.setText("This is head");

tv.setTextSize(TypedValue.COMPLEX_UNIT_DIP,32);

TextView foot = new TextView(this);

foot.setText("This is foot");

foot.setTextSize(TypedValue.COMPLEX_UNIT_DIP,32);

adapter.addHeaderView(tv);

adapter.addFooterView(foot);

rv.setAdapter(adapter);

}

#4 Demo：

demo09 RecyclerViewHeadFoot