RecyclerView（一）

public class LinearRecyclerViewActivity extends AppCompatActivity {

    RecyclerView mRvMain;

@Override
protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
setContentView(R.layout.activity_linear_recycler_view);
mRvMain= findViewById(R.id.rv_main);
LinearLayoutManager manager =  new LinearLayoutManager(this);　　//LinearRecyclerViewActivity.this
mRvMain.setLayoutManager(manager);
mRvMain.setAdapter(new LinearAdapter());
}
}

二 Adapter

public class LinearAdapter extends RecyclerView.Adapter <LinearAdapter.LinearViewHolder>{//一、这里是后面自己定义的holder
    @NonNull
    @Override
    //一、因为返回值是RecyclerView.ViewHolder(因为LinearViewHolder是ViewHolder的子类，所以直接使用linearviewholder)我们就要new一个ViewHolder作为返回值，因为没有类所有就新建一个LinearViewHolder（下面第三步）,并创建对象
    public LinearAdapter.LinearViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

            View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_linear_item,parent,false);
            return new LinearViewHolder(view); //二、LinearViewHolder类构造函数需要一个view对象 就必须传入View对象,并且所以使用打气筒将显示item,inflate将XML文件转换成View对象，赋值给新建对象
    }

    @Override
    public void onBindViewHolder(LinearAdapter.LinearViewHolder holder, int position) {
        holder.mtv.setText("你好"+position );
    }

    @Override
    public int getItemCount() {
        return 20;
    }


////////自己定义的Holder///////////
//三、
    class LinearViewHolder extends RecyclerView.ViewHolder
    {

        private TextView mtv;
        public LinearViewHolder(@NonNull View itemView) {   //itemView 的值是 开头onCreateViewHolder传出的值
            super(itemView);
            mtv=itemView.findViewById(R.id.tv_tile);
        }
    }
}

LinearRecyclerViewActivity.this