RecyclerView和各种LayoutManager都没有直接的方法添加header和footer，因此我们就需要思考如何为RecyclerView添加header和footer了。
这里我的解决方案和网上你能搜到的大多数方案一样，是通过控制Adapter的itemType来设置的，思路就是根据不同的itemType去加载不同的布局。
先po上完整代码
public class PubuAdapter extends RecyclerView.Adapter<PubuAdapter.PubuHolder> {
public static final int TYPE_HEADER = 0;
public static final int TYPE_FOOTER = 1;
public static final int TYPE_NORMAL = 2;
private List<DataBean> mList;
//HeaderView, FooterView
private View mHeaderView;
private View mFooterView;
public PubuAdapter(List<DataBean> mList) {
this.mList=mList;
}
public View getmHeaderView() {
return mHeaderView;
}
public void setmHeaderView(View mHeaderView) {
this.mHeaderView = mHeaderView;
//shouweicharu
notifyItemInserted(0);
}
public View getmFooterView() {
return mFooterView;
}
public void setmFooterView(View mFooterView) {
this.mFooterView = mFooterView;
if (mHeaderView==null){
notifyItemInserted(mList.size());
}else {
notifyItemInserted(mList.size()+1);
}
}
@Override
public int getItemViewType(int position) {
if (mHeaderView==null){
if (mFooterView==null){
return TYPE_NORMAL;
}else{
if (position==mList.size()){
return TYPE_FOOTER;
}else{
return TYPE_NORMAL;
}
}
}else {
if (position==0){
return TYPE_HEADER;
}else{
if (mFooterView==null){
return TYPE_NORMAL;
}else{
if (position!=mList.size()+1){
return TYPE_NORMAL;
}else{
return TYPE_FOOTER;
}
}
}
}
}
@Override
public PubuHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (mHeaderView!=null&&viewType==TYPE_HEADER){
return new PubuHolder(mHeaderView);
}else if (mFooterView!=null&&viewType==TYPE_FOOTER){
return new PubuHolder(mFooterView);
}
return new PubuHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.recycle_item,parent,false));
}
@Override
public void onBindViewHolder(PubuHolder holder, int position) {
if (getItemViewType(position)==TYPE_HEADER||getItemViewType(position)==TYPE_FOOTER){
return;
}else if (getItemViewType(position)==TYPE_NORMAL){
holder.imageView.setImageResource(mList.get(position-1).getImage());
holder.textView.setText(mList.get(position-1).getText());
//如果设置了回调，则设置点击事件
final int realPosition = getRealPosition(holder);
if(mOnItemClickListener!=null){
holder.imageView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// int pos=holder.getLayoutPosition();//布局真正的position，recyclerView进行添加，移除item时，会导致position位置变化
mOnItemClickListener.onItemClick(v,realPosition);
}
});
holder.imageView.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
// int pos=holder.getLayoutPosition();//布局真正的position，recyclerView进行添加，移除item时，会导致position位置变化
mOnItemClickListener.onItemLongClick(v,realPosition);
return false;
}
});
}
}
}
//重写此方法，判断recyclerview的layoutmanager为GridLayoutManager的时候，是header和footer独占一行，而不是一个item
@Override
public void onAttachedToRecyclerView(final RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
if (layoutManager instanceof GridLayoutManager){
final GridLayoutManager gridLayoutManager = (GridLayoutManager) layoutManager;
gridLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
@Override
public int getSpanSize(int position) {
return getItemViewType(position)==TYPE_HEADER||getItemViewType(position)==TYPE_FOOTER?gridLayoutManager.getSpanCount():1;
}
});
}
}
//重写此方法，判断recyclerview的layoutmanager为StaggeredGridLayoutManager的时候，是header和footer独占一行，而不是一个item
@Override
public void onViewAttachedToWindow(PubuHolder holder) {
super.onViewAttachedToWindow(holder);
ViewGroup.LayoutParams layoutParams = holder.itemView.getLayoutParams();
if (layoutParams!=null&&layoutParams instanceof StaggeredGridLayoutManager.LayoutParams){
StaggeredGridLayoutManager.LayoutParams params = (StaggeredGridLayoutManager.LayoutParams) layoutParams;
params.setFullSpan(getItemViewType(holder.getLayoutPosition())==TYPE_HEADER||getItemViewType(holder.getLayoutPosition())==TYPE_FOOTER);
}
}
//获取item的真实位置
private int getRealPosition(RecyclerView.ViewHolder viewHolder){
int layoutPosition = viewHolder.getLayoutPosition();
return mHeaderView==null?layoutPosition:layoutPosition-1;
}
@Override
public int getItemCount() {
if (mHeaderView==null){
if (mFooterView==null){
return mList.size();
}else {
return mList.size()+1;
}
}else{
if (mFooterView==null){
return mList.size()+1;
}else {
return mList.size()+2;
}
}
}
class PubuHolder extends RecyclerView.ViewHolder{
ImageView imageView;
TextView textView;
public PubuHolder(View itemView) {
super(itemView);
if (itemView==mHeaderView)return;
imageView= (ImageView) itemView.findViewById(R.id.pubu_img);
textView= (TextView) itemView.findViewById(R.id.pubu_txt);
}
}
interface onItemClickListener{
void onItemClick(View view, int position);
void onItemLongClick(View view, int position);
}
private onItemClickListener mOnItemClickListener;
public void setOnItemClickListener(onItemClickListener mOnItemClickListener) {
this.mOnItemClickListener = mOnItemClickListener;
}
}```
>这里我们重写了getItemViewType方法，并根据位置来返回不同的type，这个type是我们预先商定好的常量，接在onCreateViewHolder方法中来判断itemType，如果是header，则返回我们设置的headerView，如果是footer，则返回我们设置的footerView，否则正常加载item布局
Activity中的使用
mRecycleView= (RecyclerView) findViewById(R.id.recycle_view);
adapter=new PubuAdapter(mList);
adapter.setOnItemClickListener(new PubuAdapter.onItemClickListener() {
@Override
public void onItemClick(View view, int position) {
Toast.makeText(MainActivity.this,(position+1)+"click", Toast.LENGTH_SHORT).show();
}
@Override
public void onItemLongClick(View view, int position) {
Toast.makeText(MainActivity.this,(position+1)+"long click", Toast.LENGTH_SHORT).show();
adapter.removeData(position);
}
});
//先设置layoutmanager,再添加headre、footer
mRecycleView.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.VERTICAL,false));
adapter.setmHeaderView(LayoutInflater.from(this).inflate(R.layout.header,mRecycleView,false));
View footer = LayoutInflater.from(this).inflate(R.layout.footer, mRecycleView, false);
adapter.setmFooterView(footer);
mRecycleView.setAdapter(adapter);```
当使用GridLayoutManager和StaggeredGridLayoutManager的时候会出现header和footer占一个item而不是一行的问题，我们需要重写Adapter里面的两个方法来处理这个问题
//重写此方法，判断recyclerview的layoutmanager为GridLayoutManager的时候，是header和footer独占一行，而不是一个item
@Override
public void onAttachedToRecyclerView(final RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
if (layoutManager instanceof GridLayoutManager){
final GridLayoutManager gridLayoutManager = (GridLayoutManager) layoutManager;
gridLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
@Override
public int getSpanSize(int position) {
return getItemViewType(position)==TYPE_HEADER||getItemViewType(position)==TYPE_FOOTER?gridLayoutManager.getSpanCount():1;
}
});
}
}
//重写此方法，判断recyclerview的layoutmanager为StaggeredGridLayoutManager的时候，是header和footer独占一行，而不是一个item
@Override
public void onViewAttachedToWindow(PubuHolder holder) {
super.onViewAttachedToWindow(holder);
ViewGroup.LayoutParams layoutParams = holder.itemView.getLayoutParams();
if (layoutParams!=null&&layoutParams instanceof StaggeredGridLayoutManager.LayoutParams){
StaggeredGridLayoutManager.LayoutParams params = (StaggeredGridLayoutManager.LayoutParams) layoutParams;
params.setFullSpan(getItemViewType(holder.getLayoutPosition())==TYPE_HEADER||getItemViewType(holder.getLayoutPosition())==TYPE_FOOTER);
}
}```
效果如下
