Android开发之RecyclerView

找不到RecyclerView？

1.打开Project Structure（ctrl + alt + shift + s）

2.如图找到v7点击加号

3.选择第一项Library dependence

4.在新窗口中的搜索框中搜索RecyclerView

RecyclerView的基本使用

android.support.v7.widget.RecyclerView

android.support.v7.widget.RecyclerView.Adapter

  RecyclerView封装了ViewHolder，可以直接通过传RecyclerView内容布局给onCreateViewHolder方法创建ViewHolder，然后可以在一个继承于RecyclerView.ViewHolder的类中获取布局中的控件，RecyclerView内容的更新在方法onBindViewHolder中实现，RecyclerView的item数量在方法getItemCount中返回。实现一个基本的RecyclerView只需要3个方法和一个ViewHolder类。

以下为demo：

MainActivity.class

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;


public class MainActivity extends AppCompatActivity {

    private RecyclerView recyclerView;
    private MyAdapter adapter;
    private boolean flag=false;
    private String[] myDataset=new String[15];
    private final static String TAG=MainActivity.class.getSimpleName();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        recyclerView=findViewById(R.id.recy);
        int i=0;
        while(i<15){
            myDataset[i]=""+i;
            ++i;
        }
        RecyclerView.LayoutManager layoutManager;
        recyclerView.setHasFixedSize(true);
        layoutManager=new LinearLayoutManager(this);
        recyclerView.setLayoutManager(layoutManager);
        adapter=new MyAdapter(myDataset);
        upData();
    }

    private void upData(){
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                adapter.setRefreshList(new MyAdapter.RefreshList() {
                    @Override
                    public void refresh() {
                        myDataset[adapter.positions]="change";
                        flag=true;
                        upData();
                    }
                });
                myDataset[8]="init";
                if(flag){
                    Log.i(TAG,"flag==true");
                    //以下可实现只刷新第position条item
                    //adapter.notifyItemChanged(adapter.positions);
                    adapter.notifyDataSetChanged();
                    flag=false;
                }else{
                    recyclerView.setAdapter(adapter);
                }
            }
        });
    }
}

MyAdapter.class:

import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;

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

    private String[] myDataset;
    private RefreshList refreshList;
    public int positions,offeset;

    public MyAdapter(String[] myDataset){
        this.myDataset=myDataset;
    }
    @Override
    public void onBindViewHolder(final ViewHolder holder, final int position){
        holder.textView.setText(myDataset[position]);
        holder.button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                holder.textView.setText("点击了");
                positions=position;
                refreshList.refresh();
            }
        });
    }
    @Override
    public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View v= LayoutInflater.from(parent.getContext()).inflate(R.layout.recyclerview_layout,parent,false);
        ViewHolder vh=new ViewHolder(v);
        return vh;
    }
    @Override
    public int getItemCount() {
        return myDataset.length;
    }
    public static class ViewHolder extends RecyclerView.ViewHolder{
        private Button button;
        private TextView textView;
        private ViewHolder(View itemView) {
            super(itemView);
            textView=itemView.findViewById(R.id.textView);
            button=itemView.findViewById(R.id.butt);
        }
    }
    public interface RefreshList{
        void refresh();
    }

    public void setRefreshList(RefreshList refreshlist){
        this.refreshList=refreshlist;
    }
}

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recy"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="visible"/>

</LinearLayout>

recyclerview_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal">

    <TextView
        android:id="@+id/textView"
        android:layout_width="150dp"
        android:layout_height="30dp" />

    <Button
        android:id="@+id/butt"
        android:layout_width="80dp"
        android:layout_height="50dp"
        android:text="确定"/>

</LinearLayout>