RecyclerView和购物车的简单结合使用

首先先导入依赖：       

compile 'com.squareup.okhttp3:okhttp:3.9.0'compile 'com.squareup.okhttp3:logging-interceptor:3.9.0'compile 'com.google.code.gson:gson:2.8.2'compile 'com.android.support:recyclerview-v7:26.0.0-alpha1'compile 'com.nostra13.universalimageloader:universal-image-loader:1.9.5'compile 'org.greenrobot:eventbus:3.1.1'

然后分类建包，这个就不用在这里展示了，

下来就先写网络请求OkHttpUtils

import okhttp3.Callback;import okhttp3.OkHttpClient;import okhttp3.Request;import okhttp3.logging.HttpLoggingInterceptor;public class HttpUtils {    private static volatile HttpUtils httpUtils;    private OkHttpClient client;    private HttpUtils(){        HttpLoggingInterceptor logging=new HttpLoggingInterceptor();        logging.setLevel(HttpLoggingInterceptor.Level.BODY);        client=new OkHttpClient.Builder()                .addInterceptor(logging)                .build();    }    public static HttpUtils getHttpUtils(){        if (httpUtils==null){            synchronized (HttpUtils.class){                if (httpUtils==null){                    httpUtils=new HttpUtils();                }            }        }        return httpUtils;    }    /**     * GET请求     *     * @param url     * @param callback     */    public void doGet(String url, Callback callback){        Request request=new Request.Builder().url(url).build();        client.newCall(request).enqueue(callback);    }}
然后在这里建一个接口来实现model层的方法。
public interface OnNetListener<T> {    public void onSuccess(T t);//这是成功的方法    public void onFailure(Exception e);//这是失败的。}
下面写一个APP类的方法。这个方法是ImageLoader的方法，用来展示图片
public class MyApp extends Application {    @Override    public void onCreate() {        super.onCreate();        ImageLoaderConfiguration configuration=new                ImageLoaderConfiguration.Builder(this).build();        ImageLoader.getInstance().init(configuration);    }}
上面的一些必须的代码就写完了，接下来写model层的接口
public interface IMainModel {    public void getGoods(OnNetListener<GoodsBean> onNetListener);}
然后创建一个类来继承这个接口
import android.os.Handler;import android.os.Looper;import com.bwie.test.a09ashopcar.bean.GoodsBean;import com.bwie.test.a09ashopcar.net.Api;import com.bwie.test.a09ashopcar.net.HttpUtils;import com.bwie.test.a09ashopcar.net.OnNetListener;import com.google.gson.Gson;import java.io.IOException;import okhttp3.Call;import okhttp3.Callback;import okhttp3.Response;public class MainModel implements IMainModel{    private Handler handler=new Handler(Looper.getMainLooper());    @Override    public void getGoods(final OnNetListener<GoodsBean> onNetListener) {        HttpUtils.getHttpUtils().doGet(Api.url, new Callback() {            @Override            public void onFailure(Call call, IOException e) {            }            @Override            public void onResponse(Call call, Response response) throws IOException {                String string=response.body().string();                final GoodsBean goodsBean = new Gson().fromJson(string, GoodsBean.class);                handler.post(new Runnable() {                    @Override                    public void run() {                        onNetListener.onSuccess(goodsBean);                    }                });            }       });    }}
model层写完了， 接下来就该写presenter的数据了
public class MainPresenter {    private IMainModel iMainModel;    private IShopActivity iMainActivity;    public MainPresenter(IShopActivity iMainActivity){        this.iMainActivity=iMainActivity;        iMainModel=new MainModel();        }    public void getGoods(){        iMainModel.getGoods(new OnNetListener<GoodsBean>() {            @Override            public void onSuccess(GoodsBean goodsBean) {                List<GoodsBean.DataBean> groupList = goodsBean.getData();                List<List<GoodsBean.DataBean.DatasBean>>childList=new ArrayList<List<GoodsBean.DataBean.DatasBean>>();                for (int i=0;i<groupList.size();i++){                    List<GoodsBean.DataBean.DatasBean>datas=groupList.get(i).getDatas();                    childList.add(datas);                }                iMainActivity.showList(groupList,childList);            }            @Override            public void onFailure(Exception e) {            }        });    }}
写完这些就该写布局了
 购物车它是二级的，所以布局也比较复杂
下面这个是主要的布局
main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/activity_main"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    tools:context="com.bwie.test.a09ashopcar.view.ShopActivity">    <RelativeLayout        android:layout_width="match_parent"        android:layout_height="50dp"        android:background="#C0C1A0FA">        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="购物车"            android:textSize="22sp"            android:layout_centerVertical="true"            android:layout_centerHorizontal="true"            android:textColor="#ff000036"/>    </RelativeLayout>        <ExpandableListView        android:id="@+id/elv"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_weight="1">    </ExpandableListView>    <RelativeLayout        android:layout_width="match_parent"        android:layout_height="50dp"        android:layout_alignParentBottom="true"        android:background="@android:color/white"        android:gravity="center_vertical">        <CheckBox            android:id="@+id/quan_ck"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_centerVertical="true"            android:layout_marginLeft="10dp"            android:focusable="false"/>        <TextView            android:layout_width="wrap_content"            android:layout_height="50dp"            android:layout_centerVertical="true"            android:layout_marginLeft="10dp"            android:layout_toRightOf="@+id/quan_ck"            android:gravity="center_vertical"            android:text="全选"            android:textSize="20sp" />        <LinearLayout            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_alignParentRight="true"            android:orientation="horizontal">            <TextView                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:layout_marginLeft="10dp"                android:textSize="18sp"                android:text="合计 ：" />            <TextView                android:id="@+id/tv_price"                android:layout_width="wrap_content"                android:layout_height="50dp"                android:layout_marginLeft="10dp"                android:paddingRight="10dp"                android:text="0"                android:textColor="@android:color/holo_red_light" />            <TextView                android:id="@+id/tv_num"                android:layout_width="wrap_content"                android:layout_height="50dp"                android:background="#ff3306"                android:gravity="center"                android:padding="10dp"                android:text="结算(0)"                android:textColor="@android:color/white" />        </LinearLayout>    </RelativeLayout></LinearLayout>
下来写一级目录的布局吧。Group.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="100dp"    android:orientation="horizontal"    android:gravity="center_vertical">    <CheckBox        android:id="@+id/cb_group"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginBottom="30dp"        android:layout_marginLeft="20dp"        android:layout_marginTop="30dp"        android:focusable="false" />    <TextView        android:id="@+id/tv_sign"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginLeft="20dp"        android:text="标记" />    <TextView        android:id="@+id/tv_number"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginLeft="20dp"        android:text="12345678" /></LinearLayout>
下来是二级目录的布局  child.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:background="@android:color/darker_gray"    android:gravity="center_vertical"    android:orientation="horizontal">    <CheckBox        android:id="@+id/cb_child"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginBottom="30dp"        android:layout_marginLeft="40dp"        android:layout_marginTop="30dp"        android:focusable="false" />    <LinearLayout        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:orientation="vertical">        <TextView            android:id="@+id/tv_tel"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_marginLeft="20dp"            android:text="iphone6"/>        <TextView            android:id="@+id/tv_content"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_marginLeft="20dp"            android:text="什么手机" />        <TextView            android:id="@+id/tv_time"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_marginLeft="20dp"            android:text="2016-12-10" />    </LinearLayout>    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_weight="1"        android:orientation="vertical">        <TextView            android:id="@+id/tv_pri"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="¥3000.00" />        <LinearLayout            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:gravity="center_vertical">            <ImageView                android:id="@+id/iv_del"                android:layout_width="20dp"                android:layout_height="20dp"                android:src="@drawable/shopcart_minus_grey" />            <TextView                android:id="@+id/tv_num"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:layout_marginLeft="5dp"                android:background="@drawable/shopcart_add_btn"                android:paddingBottom="2dp"                android:paddingLeft="20dp"                android:paddingRight="20dp"                android:paddingTop="2dp"                android:text="1" />            <ImageView                android:id="@+id/iv_add"                android:layout_width="20dp"                android:layout_height="20dp"                android:layout_marginLeft="5dp"                android:src="@drawable/shopcart_add_red" />        </LinearLayout>    </LinearLayout>    <TextView        android:id="@+id/tv_del"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="删除"        /></LinearLayout>
    接下来我们改写View层的接口
 
public interface IShopActivity {    public void showList(List<GoodsBean.DataBean>groupList,List<List<GoodsBean.DataBean.DatasBean>>childList);}
然后是View的类
public class ShopActivity extends AppCompatActivity implements IShopActivity {    private ExpandableListView mElv;    private CheckBox mQuanCk;    /**     * 0     */    private TextView mTvPrice;    /**     * 结算(0)     */    private TextView mTvNum;    private LinearLayout mActivityMain;    private ShopAdapter adapter;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_shop);        EventBus.getDefault().register(this);        initView();        new MainPresenter(this).getGoods();        mQuanCk.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                adapter.changeAllListCbState(mQuanCk.isChecked());            }        });    }    private void initView() {        mElv = (ExpandableListView) findViewById(R.id.elv);        mQuanCk = (CheckBox) findViewById(R.id.quan_ck);        mTvPrice = (TextView) findViewById(R.id.tv_price);        mTvNum = (TextView) findViewById(R.id.tv_num);        mActivityMain = (LinearLayout) findViewById(R.id.activity_main);    }    @Override    public void showList(List<GoodsBean.DataBean> groupList, List<List<GoodsBean.DataBean.DatasBean>> childList) {        adapter=new ShopAdapter(this,groupList,childList);        mElv.setAdapter(adapter);        //去掉二级列表的小箭头        mElv.setGroupIndicator(null);        //默认让其全部展开        for (int i=0;i<groupList.size();i++){            mElv.expandGroup(i);        }    }    @Subscribe    public void onMessageEvent(MessageEvent event) {        mQuanCk.setChecked(event.isChecked());    }    @Subscribe    public void onMessageEvent(PriceAndCountEvent event) {        mTvNum.setText("结算(" + event.getCount() + ")");        mTvPrice.setText(event.getPrice() + "");    }}
在这里 我们用到了EventBus这个控件，所以我们这里还有这样两个类：
public class MessageEvent {    private boolean checked;    public boolean isChecked() {        return checked;    }    public void setChecked(boolean checked) {        this.checked = checked;    }}
public class PriceAndCountEvent {    private int price;    private int count;    public int getPrice() {        return price;    }    public void setPrice(int price) {        this.price = price;    }    public int getCount() {        return count;    }    public void setCount(int count) {        this.count = count;    }}
接下来我们来写最重要的购物车的适配器
public class ShopAdapter extends BaseExpandableListAdapter {    private Context context;    private List<GoodsBean.DataBean>groupList;    private List<List<GoodsBean.DataBean.DatasBean>>childList;    private final LayoutInflater inflater;    public ShopAdapter(Context context, List<GoodsBean.DataBean> groupList, List<List<GoodsBean.DataBean.DatasBean>> childList) {        this.context = context;        this.groupList = groupList;        this.childList = childList;        inflater=LayoutInflater.from(context);    }    @Override    public int getGroupCount() {        return groupList.size();    }    @Override    public int getChildrenCount(int i) {        return childList.get(i).size();    }    @Override    public Object getGroup(int i) {        return groupList.get(i);    }    @Override    public Object getChild(int i, int i1) {        return childList.get(i).get(i1);    }    @Override    public long getGroupId(int i) {        return i;    }    @Override    public long getChildId(int i, int i1) {        return i1;    }    @Override    public boolean hasStableIds() {        return false;    }    @Override    public View getGroupView(final int i, boolean b, View convertView, ViewGroup viewGroup) {        View view;        final GroupViewHolder gholder;        if (convertView==null){            gholder=new GroupViewHolder();            view=inflater.inflate(R.layout.item_group,null);            gholder.cb_group=view.findViewById(R.id.cb_group);            gholder.tv_number=view.findViewById(R.id.tv_number);            view.setTag(gholder);        }else {            view=convertView;            gholder= (GroupViewHolder) view.getTag();        }        final GoodsBean.DataBean groupBean=groupList.get(i);        gholder.cb_group.setChecked(groupBean.isChecked());        gholder.tv_number.setText(groupBean.getTitle());        //一级checkbox        gholder.cb_group.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                groupBean.setChecked(gholder.cb_group.isChecked());                changeChildCbState(i, gholder.cb_group.isChecked());                EventBus.getDefault().post(compute());                changeAllCbState(isAllGroupCbSelected());                notifyDataSetChanged();            }        });        return view;    }    @Override    public View getChildView(final int i, final int i1, boolean b, final View convertView, ViewGroup viewGroup) {        View view;        final ChildViewHolder cholder;        if (convertView==null){            cholder=new ChildViewHolder();            view=inflater.inflate(R.layout.item_child,null);            cholder.cb_child=view.findViewById(R.id.cb_child);            cholder.tv_tel=view.findViewById(R.id.tv_tel);            cholder.tv_content=view.findViewById(R.id.tv_content);            cholder.tv_time=view.findViewById(R.id.tv_time);            cholder.tv_pri=view.findViewById(R.id.tv_pri);            cholder.tv_del=view.findViewById(R.id.tv_del);            cholder.iv_add = view.findViewById(R.id.iv_add);            cholder.iv_del = view.findViewById(R.id.iv_del);            cholder.tv_num = view.findViewById(R.id.tv_num);            view.setTag(cholder);        }else {            view=convertView;            cholder= (ChildViewHolder) view.getTag();        }        final GoodsBean.DataBean.DatasBean childBean=childList.get(i).get(i1);        cholder.cb_child.setChecked(childBean.isChecked());        cholder.tv_tel.setText(childBean.getType_name());        cholder.tv_content.setText(childBean.getMsg());        cholder.tv_time.setText(childBean.getAdd_time());        cholder.tv_pri.setText(childBean.getPrice()+"");        cholder.tv_num.setText(childBean.getNum() + "");        //二级checkbox        //给holder.cbChild设置点击事件        cholder.cb_child.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                //设置该条目对象里的checked属性值                childBean.setChecked(cholder.cb_child.isChecked());                PriceAndCountEvent priceAndCountEvent=compute();                EventBus.getDefault().post(priceAndCountEvent);                if (cholder.cb_child.isChecked()){                    //当前checkbox是选中状态                    if (isAllChildCbSelected(i)){                        changGroupCbState(i,true);                        changeAllCbState(isAllGroupCbSelected());                    }                }else {                    changGroupCbState(i,false);                    changeAllCbState(isAllGroupCbSelected());                }                notifyDataSetChanged();            }        });        //加号        cholder.iv_add.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                int num=childBean.getNum();                cholder.tv_num.setText(++num+"");                childBean.setNum(num);                if (cholder.cb_child.isChecked()){                    PriceAndCountEvent priceAndCountEvent=compute();                    EventBus.getDefault().post(priceAndCountEvent);                }            }        });        //减号        cholder.iv_del.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                int num=childBean.getNum();                if (num==1){                    Toast.makeText(context,"最少留一个呗！",Toast.LENGTH_SHORT).show();                    return;                }                cholder.tv_num.setText(--num+"");                childBean.setNum(num);                if (cholder.cb_child.isChecked()){                    PriceAndCountEvent priceAndCountEvent=compute();                    EventBus.getDefault().post(priceAndCountEvent);                }            }        });        //删除        cholder.tv_del.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                List<GoodsBean.DataBean.DatasBean> datasBeen = childList.get(i);                GoodsBean.DataBean.DatasBean remove = datasBeen.remove(i1);                if (datasBeen.size()==0){                    childList.remove(i);                    groupList.remove(i);                }                EventBus.getDefault().post(compute());                notifyDataSetChanged();            }        });        return view;    }    @Override    public boolean isChildSelectable(int i, int i1) {        return false;    }    class GroupViewHolder{        CheckBox cb_group;        TextView tv_number;    }    class ChildViewHolder{        CheckBox cb_child;        TextView tv_tel;        TextView tv_content;        TextView tv_time;        TextView tv_pri;        TextView tv_del;        ImageView iv_del;        ImageView iv_add;        TextView tv_num;    }    /**     * 改变全选的状态     *     * @param flag     */        private void changeAllCbState(boolean flag){            MessageEvent messageEvent = new MessageEvent();            messageEvent.setChecked(flag);            EventBus.getDefault().post(messageEvent);        }    /**     * 改变一级列表checkbox状态     *     * @param groupPosition     */    private void changGroupCbState(int groupPosition,boolean flag){        GoodsBean.DataBean dataBean = groupList.get(groupPosition);        dataBean.setChecked(flag);    }    /**     * 改变二级列表checkbox状态     *     * @param groupPosition     * @param flag     */    private void changeChildCbState(int groupPosition, boolean flag) {        List<GoodsBean.DataBean.DatasBean> datasBeen = childList.get(groupPosition);        for (int i = 0; i <datasBeen.size() ; i++) {            GoodsBean.DataBean.DatasBean datasBean = datasBeen.get(i);            datasBean.setChecked(flag);        }    }    /**     * 判断一级列表是否全部选中     *     * @return     */    private boolean isAllGroupCbSelected() {        for (int i = 0; i <groupList.size() ; i++) {            GoodsBean.DataBean dataBean = groupList.get(i);            if (!dataBean.isChecked()){                return false;            }        }        return true;    }    /**     * 判断二级列表是否全部选中     *     * @param groupPosition     * @return     */    private boolean isAllChildCbSelected(int groupPosition){        List<GoodsBean.DataBean.DatasBean> datasBeen = childList.get(groupPosition);        for (int i=0;i<datasBeen.size();i++){            GoodsBean.DataBean.DatasBean datasBean = datasBeen.get(i);            if (!datasBean.isChecked()){                return false;            }        }        return true;    }    /**     * 计算列表中，选中的钱和数量     */    private PriceAndCountEvent compute(){        int count = 0;        int price = 0;        for (int i = 0; i <childList.size() ; i++) {            List<GoodsBean.DataBean.DatasBean> datasBeen = childList.get(i);            for (int j = 0; j <datasBeen.size() ; j++) {                GoodsBean.DataBean.DatasBean datasBean = datasBeen.get(j);                if (datasBean.isChecked()){                    price+=datasBean.getNum()*datasBean.getPrice();                    count+=datasBean.getNum();                }            }        }        PriceAndCountEvent priceAndCountEvent = new PriceAndCountEvent();        priceAndCountEvent.setCount(count);        priceAndCountEvent.setPrice(price);        return priceAndCountEvent;    }    /**     * 设置全选、反选     *     * @param flag     */    public void changeAllListCbState(boolean flag) {        for (int i = 0; i <groupList.size() ; i++) {            changGroupCbState(i,flag);            changeChildCbState(i,flag);        }        EventBus.getDefault().post(compute());        notifyDataSetChanged();    }}
这些就可以实现我们的二级购物车了。
我们接下来把RecyclerView的数据展示出来，用瀑布流来展示图片吧。
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:orientation="vertical">    <ImageView        android:id="@+id/re_img"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        /></LinearLayout>
这是瀑布流的子布局。
这是我们RecyclerView的适配器
public class RecyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {    private Context context;    private List<String> list;    public RecyAdapter( Context context, List<String> list) {        this.context = context;        this.list = list;    }    @Override    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        View view= LayoutInflater.from(context).inflate(R.layout.item_recy,parent,false);        return new MyViewHolder(view);    }    @Override    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {        String str = list.get(position);        MyViewHolder myviewHolder = (MyViewHolder) holder;        ImageLoader.getInstance().displayImage(str,myviewHolder.re_img);        myviewHolder.re_img.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {                Intent intent=new Intent(context, ShopActivity.class);                context.startActivity(intent);            }        });    }    @Override    public int getItemCount() {        return list.size();    }    class MyViewHolder extends RecyclerView.ViewHolder {        ImageView re_img;        public MyViewHolder(View itemView) {            super(itemView);            re_img=(ImageView)itemView.findViewById(R.id.re_img);            int width = ((Activity) context).getWindowManager().getDefaultDisplay().getWidth();            ViewGroup.LayoutParams params = re_img.getLayoutParams();            //设置图片的相对于屏幕的宽高比            params.width = width/3;            params.height =  (int) (200 + Math.random() * 400) ;            re_img.setLayoutParams(params);        }    }}
然后是我们的Activity
public class MainActivity extends AppCompatActivity {    private RecyclerView mRecy;    private String[] imgs=new String[]{        "http://img.my.csdn.net/uploads/201309/01/1378037235_3453.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037235_7476.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037235_9280.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037234_3539.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037234_6318.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037194_2965.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037193_1687.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037193_1286.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037192_8379.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037178_9374.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037177_1254.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037177_6203.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037152_6352.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037151_9565.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037151_7904.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037148_7104.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037129_8825.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037128_5291.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037128_3531.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037127_1085.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037095_7515.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037094_8001.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037093_7168.jpg",            "http://img.my.csdn.net/uploads/201309/01/1378037091_4950.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949643_6410.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949642_6939.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949630_4505.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949630_4593.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949629_7309.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949629_8247.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949615_1986.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949614_8482.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949614_3743.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949614_4199.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949599_3416.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949599_5269.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949598_7858.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949598_9982.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949578_2770.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949578_8744.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949577_5210.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949577_1998.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949482_8813.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949481_6577.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949480_4490.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949455_6792.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949455_6345.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949442_4553.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949441_8987.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949441_5454.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949454_6367.jpg",            "http://img.my.csdn.net/uploads/201308/31/1377949442_4562.jpg"    };    private RecyAdapter adapter;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        mRecy=(RecyclerView)findViewById(R.id.recy);        //给rv设置布局管理器        mRecy.setLayoutManager(new StaggeredGridLayoutManager                (3,StaggeredGridLayoutManager.VERTICAL));        List<String>list=new ArrayList<>();        for (int i = 0; i <imgs.length ; i++) {            list.add(imgs[i]);        }        //创建适配器        adapter=new RecyAdapter(MainActivity.this,list);        mRecy.setAdapter(adapter);    }}
这样我们的瀑布流也展示出来了。过程比较复杂，但是效果还是很棒的！