Recyclerview添加头布局和尾布局、item点击事件详解

简介：

本篇博客主要包括recyclerview添加多种布局以及添加头布局和尾布局，还有item点击事件

思路：

主要重写Recyclerview.Adapter中的一些方法

1.public int getItemCount()  item熟练  +2(头布局和尾布局)

2.public int getItemViewType(int position)   判断position 设置itemType

3.创建不同的ViewHolder,分别用来加载头布局，正常布局，尾布局

4.public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType)  根据viewType的不同返回不同的viewholder

5.public void onBindViewHolder(RecyclerView.ViewHolder holder, int position)  根据holder的不同绑定不同的数据 

案例：

主布局中只有一个Recyclerview,里面的item除了基本的两种类型，还有头布局和尾布局，点击基本类型跳转到另外一个Activity，显示图片

下面主要贴出Adapter和MainActivity中的代码，其他的布局文件，类比较简单就不贴出了

1.Adapter

public class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> implements View.OnClickListener {
private Context context;
private List<Person> datas;

private static final int ITEM_ONE=1;
private static final int ITEM_TWO=2;
private static final int ITEM_HEAD=3;
private static final int ITEM_FOOT=4;

private int headViewCount=1;
private int footViewCount=1;

private OnItemClickListener onItemClickListener;

public MyAdapter(Context context, List<Person> datas) {
 this.context = context;
 this.datas = datas;
}

@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
 if(viewType==ITEM_HEAD){
  View view= LayoutInflater.from(context).inflate(R.layout.item_head,parent,false);
  return new HeaderViewHolder(view);
 }else if(viewType==ITEM_FOOT){
  View view=LayoutInflater.from(context).inflate(R.layout.item_foot,parent,false);
  return new FootViewHolder(view);
 }

else if(viewType==ITEM_ONE){
  View view= LayoutInflater.from(context).inflate(R.layout.item_recyclerview,parent,false);
  return new ViewHolder(view);
 }else if(viewType==ITEM_TWO){
  View view=LayoutInflater.from(context).inflate(R.layout.item_recyclerview2,parent,false);
  return new ViewHolder(view);
 }

return null;

}

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {
 if(holder instanceof HeaderViewHolder){

}else if(holder instanceof FootViewHolder){

}

else if(holder instanceof ViewHolder){
  //注意除去头布局
  holder.itemView.setTag(position-1);
  holder.itemView.setOnClickListener(this);
  ((ViewHolder)holder).img.setBackgroundResource(datas.get(position-1).getImgId());
  ((ViewHolder)holder).tv1.setText(datas.get(position-1).getName());
  ((ViewHolder)holder).tv2.setText(datas.get(position-1).getDetail());
 }
}

@Override
public int getItemCount() {
 if(datas==null){
  return headViewCount+footViewCount;
 }
 return datas.size()+headViewCount+footViewCount;
}

@Override
public int getItemViewType(int position) {
 if(isHeadView(position)){
  return ITEM_HEAD;
 }
 if(isFootView(position)){
  return ITEM_FOOT;
 }

if(position％2==0){
  return ITEM_ONE;
 }else{
  return ITEM_TWO;
 }
}

public boolean isHeadView(int position){

return headViewCount!=0&&position<headViewCount;
}
public boolean isFootView(int position){
 return footViewCount!=0&&position>=(datas.size()+headViewCount);
}

@Override
public void onClick(View view) {
 if(onItemClickListener!=null){
  onItemClickListener.onItemClick(view, (Integer) view.getTag());
 }
}

class ViewHolder extends RecyclerView.ViewHolder{
  TextView tv1,tv2;
  ImageView img;

public ViewHolder(View itemView) {
  super(itemView);
  tv1=itemView.findViewById(R.id.tv1);
  tv2=itemView.findViewById(R.id.tv2);
  img=itemView.findViewById(R.id.img);
 }
}
class HeaderViewHolder extends RecyclerView.ViewHolder{

public HeaderViewHolder(View itemView) {
  super(itemView);
 }
}
class FootViewHolder extends RecyclerView.ViewHolder{

public FootViewHolder(View itemView) {
  super(itemView);
 }
}

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

interface OnItemClickListener{
 void onItemClick(View view,int position);
}
}

2.MainActivity

public class MainActivity extends AppCompatActivity implements MyAdapter.OnItemClickListener {
private RecyclerView recyclerView;

private List<Person> datas;
private MyAdapter adapter;

private int[] imgs={R.drawable.p1,R.drawable.p2,R.drawable.p3,R.drawable.p4,R.drawable.p5,R.drawable.pic1,
  R.drawable.pic2,R.drawable.pic3,R.drawable.pic4,R.drawable.pic5,R.drawable.pic6};

@Override
protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 recyclerView= (RecyclerView) findViewById(R.id.recyclerview);
 initData();
 initRecyclerView();
}

private void initRecyclerView() {
 recyclerView.setLayoutManager(new LinearLayoutManager(this));
 adapter=new MyAdapter(this,datas);
 adapter.setOnItemClickListener(this);
 recyclerView.setAdapter(adapter);

}

private void initData() {
 datas=new ArrayList<>();
 for(int i=0;i<imgs.length;i++){
  Person p=new Person();
  p.setName("hahfa"+i);
  p.setDetail("今天是星期一，还有5天才能休息"+i);
  p.setImgId(imgs[i]);
  datas.add(p);
 }
}

@Override
public void onItemClick(View view, int position) {
 Intent intent=new Intent(MainActivity.this,ImageActivity.class);
 intent.putExtra("imgId",datas.get(position).getImgId());
 startActivity(intent);
}
}