RecyclerView的使用

基本使用

效果如下

MainActivity中的内容

public class MainActivity extends AppCompatActivity {
    private RecyclerView mRecyclerView;
    private List<String> mData;
    private MySimpleAdapter mAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initData();
        initView();
        mAdapter = new MySimpleAdapter(this, mData);
        mRecyclerView.setAdapter(mAdapter);

        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
        mRecyclerView.setLayoutManager(linearLayoutManager);
    }

    private void initView() {
        mRecyclerView = (RecyclerView) findViewById(R.id.id_rec);

    }

    private void initData() {
        mData = new ArrayList<String>();
        for (int i = 'A'; i <= 'z'; i++) {
            mData.add("" + (char) i);
        }
    }
}

 Extras:

设置分割线

mRecyclerView.addItemDecoration(new DividerItemDecoration(this,DividerItemDecoration.VERTICAL));

recyclerView 更新数据时，这样会导致间隔越来越大，
可以这样使用

        if(recyclerView.getItemDecorationCount()==0)
            recyclerView.addItemDecoration(new DividerItemDecoration(context,DividerItemDecoration.VERTICAL));

设置其他LayoutManager

//mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.HORIZONTAL));
//mRecyclerView.setLayoutManager(new GridLayoutManager(this,3));

 其中RecyclerView的layout在main的layout代码如下

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">


    <androidx.recyclerview.widget.RecyclerView
        android:layout_width="match_parent"
        android:id="@+id/id_rec"

        android:layout_height="match_parent" />
</RelativeLayout>

MySimpleAdapter代码如下

public class MySimpleAdapter extends RecyclerView.Adapter<MyViewHolder> {
    private LayoutInflater mInflater;
    private Context mContext;
    private List<String> mData;
    public MySimpleAdapter(Context context, List<String> data) {
        this.mContext = context;
        this.mData = data;
        mInflater = LayoutInflater.from(mContext);
    }

    @NonNull
    @Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = mInflater.inflate(R.layout.item_single_textview, parent, false);
        MyViewHolder viewHolder = new MyViewHolder(view);
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(@NonNull MyViewHolder holder, int position) {
        holder.tv.setText(mData.get(position));
    }

    @Override
    public int getItemCount() {
        return mData.size();
    }
}

class MyViewHolder extends RecyclerView.ViewHolder {
    TextView tv;
    public MyViewHolder(@NonNull View itemView) {
        super(itemView);
        tv = itemView.findViewById(R.id.id_text);
    }
}

item_single_textview.xml内容如下

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:background="#aaaaaa"
    android:layout_height="72dp"
    xmlns:tools="http://schemas.android.com/tools">

    <TextView
        android:layout_width="match_parent"
        android:id="@+id/id_text"
        android:gravity="center"
        tools:text="Hello,World"
        android:layout_height="match_parent" />0
</FrameLayout>