RecyclerView的基本使用

一、添加gradle依赖。

二、RecyclerView实现垂直滚动的列表：

1.RecyclerView适配器：

public class BombAdapter extends RecyclerView.Adapter<BombAdapter.ViewHolder>{    private List<Bomb> mList;    private Context mContext;    public BombAdapter (Context context,List<FruitBean> list){        mList = list;        mContext = context;    }    @Override    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        LayoutInflater inflater = LayoutInflater.from(mContext);        View view = inflater.inflate(R.layout.item,null);        ViewHolder viewHolder = new ViewHolder(view);        return viewHolder;    }    @Override    public void onBindViewHolder(ViewHolder holder, int position) {        Bomb bomb = mList.get(position);        holder.imageView.setImageResource(bomb .imageId);        holder.textView.setText(bomb .fruitName);    }    @Override    public int getItemCount() {        return mList.size();    }    static class ViewHolder extends RecyclerView.ViewHolder{        ImageView imageView;        TextView textView;        public ViewHolder(View itemView) {            super(itemView);            imageView = (ImageView) itemView.findViewById(R.id.imageView);            textView = (TextView) itemView.findViewById(R.id.textView);        }    }}

2.MainActivity代码：

public class MainActivity extends Activity {    private RecyclerView recyclerView;    private List<Bomb> bombList = new ArrayList<>();    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initData();        initView();    }    private void initData() {        for (int i=0;i<2;i++){            Bomb bomb5 = new Bomb("我是bomb 1 哦",R.drawable.bomb5);            bombList.add(bomb5);            Bomb bomb6 = new Bomb("我是bomb 2 哦",R.drawable.bomb6);            bombList.add(bomb6);            Bomb bomb7 = new Bomb("我是bomb 3 哦",R.drawable.bomb7);            bombList.add(bomb7);            Bomb bomb8 = new Bomb("我是bomb 4 哦",R.drawable.bomb8);            bombList.add(bomb8);            Bomb bomb9 = new Bomb("我是bomb 5 哦",R.drawable.bomb9);            bombList.add(bomb9);            Bomb bomb10 = new Bomb("我是bomb 6 哦",R.drawable.bomb10);            bombList.add(bomb10);            Bomb bomb11 = new Bomb("我是bomb 7 哦",R.drawable.bomb11);            bombList.add(bomb11);            Bomb bomb12 = new Bomb("我是bomb 8 哦",R.drawable.bomb12);            bombList.add(bomb12);            Bomb bomb13 = new Bomb("我是bomb 9 哦",R.drawable.bomb13);            bombList.add(bomb13);            Bomb bomb14 = new Bomb("我是bomb 10 哦",R.drawable.bomb14);            bombList.add(bomb14);            Bomb bomb15 = new Bomb("我是bomb 11 哦",R.drawable.bomb15);            bombList.add(bomb15);            Bomb bomb16 = new Bomb("我是bomb 12 哦",R.drawable.bomb16);            bombList.add(bomb16);        }    }    private void initView() {        recyclerView = (RecyclerView) findViewById(R.id.recyclerView);        //设置recyclerView的布局方式为线性布局         LinearLayoutManager layoutManager = new LinearLayoutManager(this);        recyclerView.setLayoutManager(layoutManager);        //如果可以确定每个item的高度是固定的，设置这个选项可以提高性能        recyclerView.setHasFixedSize(true);        BombAdapter adapter = new BombAdapter(this,bombList);        recyclerView.setAdapter(adapter);    }} 

运行效果：

发现此列表是没有分割线的，当然加分割线是很简单的，完全可以在Item的布局里加水平的view，这里写个别的方法添加分割线。

先写个分割线的类：

 public class DividerLine extends RecyclerView.ItemDecoration{    /**     * 水平方向     */    public static final int HORIZONTAL = LinearLayoutManager.HORIZONTAL;    /**     * 垂直方向     */    public static final int VERTICAL = LinearLayoutManager.VERTICAL;    // 画笔    private Paint paint;    // 布局方向    private int orientation;    // 分割线颜色    private int color;    // 分割线尺寸    private int size;    public DividerLine() {        this(VERTICAL);    }    public DividerLine(int orientation) {        this.orientation = orientation;        paint = new Paint();    }    @Override    public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {        super.onDrawOver(c, parent, state);        if (orientation == VERTICAL) {            drawHorizontal(c, parent);        } else {            drawVertical(c, parent);        }    }    /**     * 设置分割线颜色     *     * @param color 颜色     */    public void setColor(int color) {        this.color = color;        paint.setColor(color);    }    /**     * 设置分割线尺寸     *     * @param size 尺寸     */    public void setSize(int size) {        this.size = size;    }    // 绘制垂直分割线    protected void drawVertical(Canvas c, RecyclerView parent) {        final int top = parent.getPaddingTop();        final int bottom = parent.getHeight() - parent.getPaddingBottom();        final int childCount = parent.getChildCount();        for (int i = 0; i < childCount; i++) {            final View child = parent.getChildAt(i);            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();            final int left = child.getRight() + params.rightMargin;            final int right = left + size;            c.drawRect(left, top, right, bottom, paint);        }    }    // 绘制水平分割线    protected void drawHorizontal(Canvas c, RecyclerView parent) {        final int left = parent.getPaddingLeft();        final int right = parent.getWidth() - parent.getPaddingRight();        final int childCount = parent.getChildCount();        for (int i = 0; i < childCount; i++) {            final View child = parent.getChildAt(i);            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();            final int top = child.getBottom() + params.bottomMargin;            final int bottom = top + size;            c.drawRect(left, top, right, bottom, paint);        }    }}

代码中使用此分割线的类：

 private void initView() {        recyclerView = (RecyclerView) findViewById(R.id.recyclerView);//设置recyclerView的布局的排列方向为纵向，默认为纵向        LinearLayoutManager layoutManager = new LinearLayoutManager(this);        layoutManager.setOrientation(LinearLayoutManager.VERTICAL);        recyclerView.setLayoutManager(layoutManager);        //如果可以确定每个item的高度是固定的，设置这个选项可以提高性能        recyclerView.setHasFixedSize(true);        //用系统默认的分割线：mRecyclerView.addItemDecoration(new DividerItemDecoration(                getActivity(), DividerItemDecoration.HORIZONTAL_LIST));        //添加自定义分割线        DividerLine dividerLine = new DividerLine(DividerLine.VERTICAL);        dividerLine.setSize(2);        dividerLine.setColor(getResources().getColor(R.color.dividerLine));        recyclerView.addItemDecoration(dividerLine);        BombAdapter adapter = new BombAdapter(this,bombList);        recyclerView.setAdapter(adapter);    }

在运行，发现分割线出来了：

三、实现RecyclerView的横向滚动的列表：

1.先将item布局改成垂直：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="60dp"     android:layout_height="match_parent"    android:gravity="center_horizontal">    <ImageView        android:id="@+id/imageView"        android:layout_width="50dp"        android:layout_height="50dp" />    <TextView        android:id="@+id/textView"        android:layout_marginTop="5dp"        android:gravity="center"        android:textSize="16sp"        android:layout_width="wrap_content"        android:layout_height="wrap_content" /></LinearLayout> 

2.MainActivity代码的innitVIew()方法加一句就ok：

private void initView() {        recyclerView = (RecyclerView) findViewById(R.id.recyclerView);        LinearLayoutManager layoutManager = new LinearLayoutManager(this);        //设置recyclerView的布局的排列方向为横向        layoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);        //设置recyclerView的布局方式为线性布局，默认布局的排列方向为横向为纵向排列        recyclerView.setLayoutManager(layoutManager);        BombAdapter adapter = new BombAdapter(this,bombList);        recyclerView.setAdapter(adapter);    }

运行：

四、实现RecyclerView的瀑布流布局：

1.将item布局改为：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:layout_margin="5dp">    <ImageView        android:id="@+id/imageView"        android:layout_width="100dp"        android:layout_height="100dp"        android:layout_gravity="center_horizontal"/>    <TextView        android:id="@+id/textView"        android:layout_marginTop="10dp"        android:layout_width="wrap_content"        android:layout_height="wrap_content"         android:layout_gravity="left"/></LinearLayout>

2.将recyclerView的布局方式改为瀑布流布局，MainActivity代码：

public class MainActivity extends Activity {    private RecyclerView recyclerView;    private List<Bomb> bombList = new ArrayList<>();    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initData();        initView();    }    private void initData() {        for (int i=0;i<2;i++){            Bomb bomb5 = new Bomb(getRandomLengthName("bomb1"),R.drawable.bomb5);            bombList.add(bomb5);            Bomb bomb6 = new Bomb(getRandomLengthName("bomb2"),R.drawable.bomb6);            bombList.add(bomb6);            Bomb bomb7 = new Bomb(getRandomLengthName("bomb3"),R.drawable.bomb7);            bombList.add(bomb7);            Bomb bomb8 = new Bomb(getRandomLengthName("bomb4"),R.drawable.bomb8);            bombList.add(bomb8);            Bomb bomb9 = new Bomb(getRandomLengthName("bomb5"),R.drawable.bomb9);            bombList.add(bomb9);            Bomb bomb10 = new Bomb(getRandomLengthName("bomb6"),R.drawable.bomb10);            bombList.add(bomb10);            Bomb bomb11 = new Bomb(getRandomLengthName("bomb7"),R.drawable.bomb11);            bombList.add(bomb11);            Bomb bomb12 = new Bomb(getRandomLengthName("bomb8"),R.drawable.bomb12);            bombList.add(bomb12);            Bomb bomb13 = new Bomb(getRandomLengthName("bomb9"),R.drawable.bomb13);            bombList.add(bomb13);            Bomb bomb14 = new Bomb(getRandomLengthName("bomb10"),R.drawable.bomb14);            bombList.add(bomb14);            Bomb bomb15 = new Bomb(getRandomLengthName("bomb11"),R.drawable.bomb15);            bombList.add(bomb15);            Bomb bomb16 = new Bomb(getRandomLengthName("bomb12"),R.drawable.bomb16);            bombList.add(bomb16);        }    }    private void initView() {        recyclerView = (RecyclerView) findViewById(R.id.recyclerView);        //第一个参数指定布局的列数为3，第二个参数指定布局排列方向        //若指定排列方向为横向，则显示三行的横向瀑布流        StaggeredGridLayoutManager layoutManager =                new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL);        recyclerView.setLayoutManager(layoutManager);        BombAdapter adapter = new BombAdapter(this,bombList);        recyclerView.setAdapter(adapter);    }    //获得名字的随机长度    private String getRandomLengthName(String name){        Random random = new Random();        int length = random.nextInt(20)+1;        StringBuilder sb = new StringBuilder();        for (int i=0;i<length;i++){            sb.append(name);        }        return sb.toString();    }}

运行：

五、实现recyclerView的网格布局：
将 StaggeredGridLayoutManager layoutManager =
new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL);
改为
GridLayoutManager layoutManager = new GridLayoutManager(this,3);
即可。运行：

六、RecyclerView的点击事件：

RecyclerView需要我们自己给子项具体的View去注册点击事件。请看修改以后的BombAdapter代码：

public class BombAdapter extends RecyclerView.Adapter<BombAdapter.ViewHolder>{    private List<Bomb> mList;    private Context mContext;    public BombAdapter(Context context, List<Bomb> list){        mList = list;        mContext = context;    }    @Override    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        LayoutInflater inflater = LayoutInflater.from(mContext);        View view = inflater.inflate(R.layout.item ,null);        final ViewHolder viewHolder = new ViewHolder(view);        //为itemView设置点击事件        viewHolder.bombView.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                //这句很重要                int position = viewHolder.getAdapterPosition();                Toast.makeText(mContext, "你点击了itemVIew----" +                         mList.get(position).fruitName, Toast.LENGTH_SHORT).show();            }        });        //为imageView设置点击事件        viewHolder.imageView.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                //这句很重要                int position = viewHolder.getAdapterPosition();                Toast.makeText(mContext, "你点击了imageVIew----" +                        mList.get(position).fruitName, Toast.LENGTH_SHORT).show();            }        });        return viewHolder;    }    @Override    public void onBindViewHolder(ViewHolder holder, int position) {        Bomb bomb = mList.get(position);        holder.imageView.setImageResource(bomb.imageId);        holder.textView.setText(bomb.fruitName);    }    @Override    public int getItemCount() {        return mList.size();    }    static class ViewHolder extends RecyclerView.ViewHolder{        View bombView;         ImageView imageView;        TextView textView;        public ViewHolder(View itemView) {            super(itemView);            bombView = itemView;            imageView = (ImageView) itemView.findViewById(R.id.imageView);            textView = (TextView) itemView.findViewById(R.id.textView);        }    }}