Recyclerview添加头布局和尾布局，点击效果

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);
    }
}