组合控件——增强型列表——循环视图RecyclerView——布局管理器LayoutManager

 

 

RecyclerView的布局样式依赖于布局管理器LayoutManager，它提供了下面3类布局管理器。

（1）线性布局管理器LinearLayoutManager

 

该管理器可看作线性布局LinearLayout，在垂直方向布局时，展示效果类似于垂直的列表视图ListView；在水平方向布局时，展示效果类似于水平的列表视图。

 

下面是LinearLayoutManager的常用方法。

 

 

 

构造函数：可指定列表的方向和是否为相反方向开始布局。

setOrientation :设置列表的方向。

setReverseLayout :设置是否为相反方向开始布局，默认false。

 

 

 

 

 

 

 

 

 

 

（2）网格布局管理器GridLayoutManager

 

该管理器可看作网格布局GridLayout，其展示效果类似于网格视图GridView。

GridLayout、GridView、GridLayoutManager都呈现多行多列的网格界面。

 

 

下面是GridLayoutManager的常用方法。

构造函数：可指定网格的列数。
setSpanCount：设置网格的列数。
setSpanSizeLookup：设置列表项的占位规则。

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

（3）瀑布流网格布局管理器StaggeredGridLayoutManager

该管理器允许使用灵活高度的格子展示每个视图，例如根据不同的商品形状展示不同高度的图片。

下面是StaggeredGridLayoutManager的常用方法。

构造函数：可指定网格的列数和方向。

setSpanCount：设置网格的列数。
setOrientation :设置列表的方向。
setReverseLayout :设置是否为相反方向开始布局，默认false。

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

=========================================================================================

 

 

 

 

 

 

 

 

xml布局：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="5dp"
    android:orientation="vertical">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv_grid"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

 

 

 

 

 

 

 

 

 

 

主代码：

package com.example.myapplication;

import android.annotation.SuppressLint;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.DefaultItemAnimator;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import com.example.myapplication.adapter.RecyclerGridAdapter;
import com.example.myapplication.bean.NewsInfo;
import com.example.myapplication.widget.SpacesDecoration;

@SuppressLint("SetTextI18n")
public class MainActivity extends AppCompatActivity
{
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        initRecyclerGrid(); // 初始化网格布局的循环视图
    }

    // 初始化网格布局的循环视图
    private void initRecyclerGrid()
    {

        // 从布局文件中获取名叫rv_grid的循环视图
        RecyclerView rv_grid = findViewById(R.id.rv_grid);

        // 创建一个网格布局管理器（每行5列）
        GridLayoutManager manager = new GridLayoutManager(this, 5);

        rv_grid.setLayoutManager(manager); // 设置循环视图的布局管理器

        // 构建一个市场列表的网格适配器
        RecyclerGridAdapter adapter = new RecyclerGridAdapter(this, NewsInfo.getDefaultGrid());

        adapter.setOnItemClickListener(adapter); // 设置网格列表的点击监听器

        adapter.setOnItemLongClickListener(adapter); // 设置网格列表的长按监听器

        rv_grid.setAdapter(adapter); // 设置循环视图的网格适配器

        rv_grid.setItemAnimator(new DefaultItemAnimator());  // 设置循环视图的动画效果

        rv_grid.addItemDecoration(new SpacesDecoration(1));  // 设置循环视图的空白装饰

    }

}

 

 

 

 

 

 

 

 

 

 

 

 

NewsInfo

package com.example.myapplication.bean;

import com.example.myapplication.R;
import java.util.ArrayList;
import java.util.List;

public class NewsInfo
{

    public int pic_id; // 图片的资源编号
    public String title; // 标题
    public String desc; // 描述
    public boolean isPressed; // 是否按下
    public int id; // 商品信息编号
    private static int seq = 0; // 序号

    public NewsInfo(int pic_id, String title, String desc)
    {

        this.pic_id = pic_id;
        this.title = title;
        this.desc = desc;
        this.isPressed = false;
        this.id = this.seq;
        this.seq++;
    }

    private static int[] newsImageArray = {R.drawable.public_01, R.drawable.public_02
            , R.drawable.public_03, R.drawable.public_04, R.drawable.public_05};

    private static String[] newsTitleArray = {
            "首都日报", "海峡时报", "东方周末", "参照消息", "挨踢杂志"};

    private static String[] newsDescArray = {
            "北京冬奥精彩纷呈，中外健儿各显神通",
            "庆祝伟大统一，闽台两地合办中秋晚会",
            "日本新娘仰慕中土，纷纷跨海嫁往上海",
            "雅万高铁建成通车，中国标准再下一城",
            "Mate40大战iPhone12，两大豪机争上游"};

    public static List<NewsInfo> getDefaultList()
    {

        List<NewsInfo> newsList = new ArrayList<NewsInfo>();
        for (int i = 0; i < newsImageArray.length; i++) {
            newsList.add(new NewsInfo(newsImageArray[i], newsTitleArray[i], newsDescArray[i]));
        }
        return newsList;
    }

    private static int[] gridImageArray = {R.drawable.pic_01, R.drawable.pic_02, R.drawable.pic_03
            , R.drawable.pic_04, R.drawable.pic_05, R.drawable.pic_06, R.drawable.pic_07
            , R.drawable.pic_08, R.drawable.pic_09, R.drawable.pic_10};

    private static String[] gridTitleArray = {"商场", "超市", "百货", "便利店",
            "地摊", "食杂店", "饭店", "餐厅", "会所", "菜市场"};

    public static List<NewsInfo> getDefaultGrid() {
        List<NewsInfo> gridList = new ArrayList<NewsInfo>();
        for (int i = 0; i < gridImageArray.length; i++) {
            gridList.add(new NewsInfo(gridImageArray[i], gridTitleArray[i], null));
        }
        return gridList;
    }

    private static int[] stagImageArray = {R.drawable.skirt01, R.drawable.skirt02, R.drawable.skirt03
            , R.drawable.skirt04, R.drawable.skirt05, R.drawable.skirt06, R.drawable.skirt07
            , R.drawable.skirt08, R.drawable.skirt09, R.drawable.skirt10, R.drawable.skirt11
            , R.drawable.skirt12, R.drawable.skirt13, R.drawable.skirt14, R.drawable.skirt15
            , R.drawable.skirt16, R.drawable.skirt17, R.drawable.skirt18, R.drawable.skirt19
            , R.drawable.skirt20, R.drawable.skirt21, R.drawable.skirt22, R.drawable.skirt23};

    private static String[] stagTitleArray = {"促销价", "惊爆价", "跳楼价", "白菜价", "清仓价", "割肉价",
            "实惠价", "一口价", "满意价", "打折价", "腰斩价", "无人问津", "算了吧", "大声点",
            "嘘嘘", "嗯嗯", "呼呼", "呵呵", "哈哈", "嘿嘿", "嘻嘻", "嗷嗷", "喔喔"};

    public static List<NewsInfo> getDefaultStag() {
        List<NewsInfo> stagList = new ArrayList<NewsInfo>();
        for (int i = 0; i < stagImageArray.length; i++) {
            stagList.add(new NewsInfo(stagImageArray[i], stagTitleArray[i], null));
        }
        return stagList;
    }

    private static int[] combineImageArray = {R.drawable.cainixihuan, R.drawable.dapaijiadao
            , R.drawable.trip_01, R.drawable.trip_02, R.drawable.trip_03, R.drawable.trip_04};
    private static String[] combineTitleArray = {
            "猜你喜欢", "大牌驾到", "买哪个", "别想了", "先下单", "包你满意"};

    public static List<NewsInfo> getDefaultCombine() {
        List<NewsInfo> combineList = new ArrayList<NewsInfo>();
        for (int i = 0; i < combineImageArray.length; i++) {
            combineList.add(new NewsInfo(combineImageArray[i], combineTitleArray[i], null));
        }
        return combineList;
    }

    private static int[] appiImageArray = {R.drawable.dian01, R.drawable.dian02, R.drawable.dian03
            , R.drawable.dian04, R.drawable.dian05, R.drawable.dian06, R.drawable.dian07
            , R.drawable.dian08, R.drawable.dian09, R.drawable.dian10, R.drawable.dian11
            , R.drawable.dian12, R.drawable.dian13, R.drawable.dian14, R.drawable.dian15};
    private static String[] appiTitleArray = {"双十一", "大聚惠", "爆款价",
            "就一次", "手慢无", "快点击", "付定金", "享特权", "包安装", "再返券",
            "白送你", "想得美", "干活去", "好好学", "才有钱"};

    public static List<NewsInfo> getDefaultAppi() {
        List<NewsInfo> appiList = new ArrayList<NewsInfo>();
        for (int i = 0; i < appiImageArray.length; i++) {
            appiList.add(new NewsInfo(appiImageArray[i], appiTitleArray[i], null));
        }
        return appiList;
    }

}

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RecyclerExtras

 

package com.example.myapplication.widget;

import android.view.View;

public class RecyclerExtras
{

    // 定义一个循环视图列表项的点击监听器接口
    public interface OnItemClickListener
    {
        void onItemClick(View view, int position);

    }

    // 定义一个循环视图列表项的长按监听器接口
    public interface OnItemLongClickListener
    {

        void onItemLongClick(View view, int position);
    }

    // 定义一个循环视图列表项的删除监听器接口
    public interface OnItemDeleteClickListener 
    {
        void onItemDeleteClick(View view, int position);
    }

}

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RecyclerGridAdapter

package com.example.myapplication.adapter;

import android.annotation.SuppressLint;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnLongClickListener;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
import androidx.recyclerview.widget.RecyclerView;
import androidx.recyclerview.widget.RecyclerView.ViewHolder;
import com.example.myapplication.R;
import com.example.myapplication.bean.NewsInfo;
import com.example.myapplication.widget.RecyclerExtras.OnItemClickListener;
import com.example.myapplication.widget.RecyclerExtras.OnItemLongClickListener;
import java.util.List;

@SuppressLint("DefaultLocale")
public class RecyclerGridAdapter extends RecyclerView.Adapter<ViewHolder> implements
        OnItemClickListener, OnItemLongClickListener {
    private final static String TAG = "RecyclerGridAdapter";
    private Context mContext; // 声明一个上下文对象
    private List<NewsInfo> mGoodsList;

    public RecyclerGridAdapter(Context context, List<NewsInfo> goodsList) {
        mContext = context;
        mGoodsList = goodsList;
    }

    // 获取列表项的个数
    public int getItemCount() {
        return mGoodsList.size();
    }

    // 创建列表项的视图持有者
    public ViewHolder onCreateViewHolder(ViewGroup vg, int viewType) {
        // 根据布局文件item_grid.xml生成视图对象
        View v = LayoutInflater.from(mContext).inflate(R.layout.item_grid, vg, false);
        return new ItemHolder(v);
    }

    // 绑定列表项的视图持有者
    public void onBindViewHolder(ViewHolder vh, @SuppressLint("RecyclerView") final int position) {
        ItemHolder holder = (ItemHolder) vh;
        holder.iv_pic.setImageResource(mGoodsList.get(position).pic_id);
        holder.tv_title.setText(mGoodsList.get(position).title);
        // 列表项的点击事件需要自己实现
        holder.ll_item.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                if (mOnItemClickListener != null) {
                    mOnItemClickListener.onItemClick(v, position);
                }
            }
        });
        // 列表项的长按事件需要自己实现
        holder.ll_item.setOnLongClickListener(new OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                if (mOnItemLongClickListener != null) {
                    mOnItemLongClickListener.onItemLongClick(v, position);
                }
                return true;
            }
        });
    }

    // 获取列表项的类型
    public int getItemViewType(int position) {
        return 0;
    }

    // 获取列表项的编号
    public long getItemId(int position) {
        return position;
    }

    // 定义列表项的视图持有者
    public class ItemHolder extends RecyclerView.ViewHolder {
        public LinearLayout ll_item; // 声明列表项的线性布局
        public ImageView iv_pic; // 声明列表项图标的图像视图
        public TextView tv_title; // 声明列表项标题的文本视图

        public ItemHolder(View v) {
            super(v);
            ll_item = v.findViewById(R.id.ll_item);
            iv_pic = v.findViewById(R.id.iv_pic);
            tv_title = v.findViewById(R.id.tv_title);
        }
    }

    // 声明列表项的点击监听器对象
    private OnItemClickListener mOnItemClickListener;

    public void setOnItemClickListener(OnItemClickListener listener) {
        this.mOnItemClickListener = listener;
    }

    // 声明列表项的长按监听器对象
    private OnItemLongClickListener mOnItemLongClickListener;

    public void setOnItemLongClickListener(OnItemLongClickListener listener) {
        this.mOnItemLongClickListener = listener;
    }

    // 处理列表项的点击事件
    public void onItemClick(View view, int position) {
        String desc = String.format("您点击了第%d项，栏目名称是%s", position + 1,
                mGoodsList.get(position).title);
        Toast.makeText(mContext, desc, Toast.LENGTH_SHORT).show();
    }

    // 处理列表项的长按事件
    public void onItemLongClick(View view, int position) {
        String desc = String.format("您长按了第%d项，栏目名称是%s", position + 1,
                mGoodsList.get(position).title);
        Toast.makeText(mContext, desc, Toast.LENGTH_SHORT).show();
    }

}

 

 

 

 

 

 

 

 

 

 

 

 

 

 

item_grid.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/ll_item"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/white"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/iv_pic"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:scaleType="fitCenter" />

    <TextView
        android:id="@+id/tv_title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:textColor="@color/black"
        android:textSize="17sp" />

</LinearLayout>

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

================================================================================================

 

 

 

 

 

 

瀑布流网格布局管理器

 

 

 

 

 

 

 

 

 

xml布局：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rv_staggered"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#ffffaa" />

</LinearLayout>

 

 

 

 

 

 

 

 

 

主代码：

package com.example.myapplication;

import android.annotation.SuppressLint;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.DefaultItemAnimator;
import androidx.recyclerview.widget.RecyclerView;
import androidx.recyclerview.widget.StaggeredGridLayoutManager;
import com.example.myapplication.adapter.RecyclerStagAdapter;
import com.example.myapplication.bean.NewsInfo;
import com.example.myapplication.widget.SpacesDecoration;

@SuppressLint("SetTextI18n")
public class MainActivity extends AppCompatActivity
{
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        initRecyclerStaggered(); // 初始化瀑布流布局的循环视图
    }

    // 初始化瀑布流布局的循环视图
    private void initRecyclerStaggered()
    {

        // 从布局文件中获取名叫rv_staggered的循环视图
        RecyclerView rv_staggered = findViewById(R.id.rv_staggered);

        // 创建一个垂直方向的瀑布流布局管理器（每行3列）
        StaggeredGridLayoutManager manager = new StaggeredGridLayoutManager(3, RecyclerView.VERTICAL);

        rv_staggered.setLayoutManager(manager); // 设置循环视图的布局管理器

        // 构建一个服装列表的瀑布流适配器
        RecyclerStagAdapter adapter = new RecyclerStagAdapter(this, NewsInfo.getDefaultStag());

        adapter.setOnItemClickListener(adapter); // 设置瀑布流列表的点击监听器

        adapter.setOnItemLongClickListener(adapter); // 设置瀑布流列表的长按监听器

        rv_staggered.setAdapter(adapter);  // 设置循环视图的瀑布流适配器

        rv_staggered.setItemAnimator(new DefaultItemAnimator());  // 设置循环视图的动画效果

        rv_staggered.addItemDecoration(new SpacesDecoration(3));  // 设置循环视图的空白装饰
    }

}

 

 

 

 

 

 

 

 

 

 

 

 

 

NewsInfo

package com.example.myapplication.bean;

import com.example.myapplication.R;
import java.util.ArrayList;
import java.util.List;

public class NewsInfo
{

    public int pic_id; // 图片的资源编号
    public String title; // 标题
    public String desc; // 描述
    public boolean isPressed; // 是否按下
    public int id; // 商品信息编号
    private static int seq = 0; // 序号

    public NewsInfo(int pic_id, String title, String desc)
    {

        this.pic_id = pic_id;
        this.title = title;
        this.desc = desc;
        this.isPressed = false;
        this.id = this.seq;
        this.seq++;
    }

    private static int[] newsImageArray = {R.drawable.public_01, R.drawable.public_02
            , R.drawable.public_03, R.drawable.public_04, R.drawable.public_05};

    private static String[] newsTitleArray = {
            "首都日报", "海峡时报", "东方周末", "参照消息", "挨踢杂志"};

    private static String[] newsDescArray = {
            "北京冬奥精彩纷呈，中外健儿各显神通",
            "庆祝伟大统一，闽台两地合办中秋晚会",
            "日本新娘仰慕中土，纷纷跨海嫁往上海",
            "雅万高铁建成通车，中国标准再下一城",
            "Mate40大战iPhone12，两大豪机争上游"};

    public static List<NewsInfo> getDefaultList()
    {

        List<NewsInfo> newsList = new ArrayList<NewsInfo>();
        for (int i = 0; i < newsImageArray.length; i++) {
            newsList.add(new NewsInfo(newsImageArray[i], newsTitleArray[i], newsDescArray[i]));
        }
        return newsList;
    }

    private static int[] gridImageArray = {R.drawable.pic_01, R.drawable.pic_02, R.drawable.pic_03
            , R.drawable.pic_04, R.drawable.pic_05, R.drawable.pic_06, R.drawable.pic_07
            , R.drawable.pic_08, R.drawable.pic_09, R.drawable.pic_10};

    private static String[] gridTitleArray = {"商场", "超市", "百货", "便利店",
            "地摊", "食杂店", "饭店", "餐厅", "会所", "菜市场"};

    public static List<NewsInfo> getDefaultGrid() {
        List<NewsInfo> gridList = new ArrayList<NewsInfo>();
        for (int i = 0; i < gridImageArray.length; i++) {
            gridList.add(new NewsInfo(gridImageArray[i], gridTitleArray[i], null));
        }
        return gridList;
    }

    private static int[] stagImageArray = {R.drawable.skirt01, R.drawable.skirt02, R.drawable.skirt03
            , R.drawable.skirt04, R.drawable.skirt05, R.drawable.skirt06, R.drawable.skirt07
            , R.drawable.skirt08, R.drawable.skirt09, R.drawable.skirt10, R.drawable.skirt11
            , R.drawable.skirt12, R.drawable.skirt13, R.drawable.skirt14, R.drawable.skirt15
            , R.drawable.skirt16, R.drawable.skirt17, R.drawable.skirt18, R.drawable.skirt19
            , R.drawable.skirt20, R.drawable.skirt21, R.drawable.skirt22, R.drawable.skirt23};

    private static String[] stagTitleArray = {"促销价", "惊爆价", "跳楼价", "白菜价", "清仓价", "割肉价",
            "实惠价", "一口价", "满意价", "打折价", "腰斩价", "无人问津", "算了吧", "大声点",
            "嘘嘘", "嗯嗯", "呼呼", "呵呵", "哈哈", "嘿嘿", "嘻嘻", "嗷嗷", "喔喔"};

    public static List<NewsInfo> getDefaultStag() {
        List<NewsInfo> stagList = new ArrayList<NewsInfo>();
        for (int i = 0; i < stagImageArray.length; i++) {
            stagList.add(new NewsInfo(stagImageArray[i], stagTitleArray[i], null));
        }
        return stagList;
    }

    private static int[] combineImageArray = {R.drawable.cainixihuan, R.drawable.dapaijiadao
            , R.drawable.trip_01, R.drawable.trip_02, R.drawable.trip_03, R.drawable.trip_04};
    private static String[] combineTitleArray = {
            "猜你喜欢", "大牌驾到", "买哪个", "别想了", "先下单", "包你满意"};

    public static List<NewsInfo> getDefaultCombine() {
        List<NewsInfo> combineList = new ArrayList<NewsInfo>();
        for (int i = 0; i < combineImageArray.length; i++) {
            combineList.add(new NewsInfo(combineImageArray[i], combineTitleArray[i], null));
        }
        return combineList;
    }

    private static int[] appiImageArray = {R.drawable.dian01, R.drawable.dian02, R.drawable.dian03
            , R.drawable.dian04, R.drawable.dian05, R.drawable.dian06, R.drawable.dian07
            , R.drawable.dian08, R.drawable.dian09, R.drawable.dian10, R.drawable.dian11
            , R.drawable.dian12, R.drawable.dian13, R.drawable.dian14, R.drawable.dian15};
    private static String[] appiTitleArray = {"双十一", "大聚惠", "爆款价",
            "就一次", "手慢无", "快点击", "付定金", "享特权", "包安装", "再返券",
            "白送你", "想得美", "干活去", "好好学", "才有钱"};

    public static List<NewsInfo> getDefaultAppi() {
        List<NewsInfo> appiList = new ArrayList<NewsInfo>();
        for (int i = 0; i < appiImageArray.length; i++) {
            appiList.add(new NewsInfo(appiImageArray[i], appiTitleArray[i], null));
        }
        return appiList;
    }

}

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

item_staggered.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/ll_item"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/white"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/iv_pic"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:scaleType="centerCrop" />

    <TextView
        android:id="@+id/tv_title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:textColor="@color/black"
        android:textSize="17sp" />

</LinearLayout>

 

 

 

 

 

 

 

 

 

 

 

 

RecyclerExtras

 

package com.example.myapplication.widget;

import android.view.View;

public class RecyclerExtras
{

    // 定义一个循环视图列表项的点击监听器接口
    public interface OnItemClickListener
    {
        void onItemClick(View view, int position);

    }

    // 定义一个循环视图列表项的长按监听器接口
    public interface OnItemLongClickListener
    {

        void onItemLongClick(View view, int position);
    }

    // 定义一个循环视图列表项的删除监听器接口
    public interface OnItemDeleteClickListener 
    {
        void onItemDeleteClick(View view, int position);
    }

}

 

 

 

 

 

 

 

 

 

 

 

 

RecyclerStagAdapter

package com.example.myapplication.adapter;

import android.annotation.SuppressLint;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnLongClickListener;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
import androidx.recyclerview.widget.RecyclerView;
import androidx.recyclerview.widget.RecyclerView.ViewHolder;
import com.example.myapplication.R;
import com.example.myapplication.bean.NewsInfo;
import com.example.myapplication.widget.RecyclerExtras.OnItemClickListener;
import com.example.myapplication.widget.RecyclerExtras.OnItemLongClickListener;
import java.util.List;

@SuppressLint("DefaultLocale")
public class RecyclerStagAdapter extends RecyclerView.Adapter<ViewHolder> implements OnItemClickListener, OnItemLongClickListener
{

    private final static String TAG = "RecyclerStagAdapter";
    private Context mContext; // 声明一个上下文对象
    private List<NewsInfo> mGoodsList;

    public RecyclerStagAdapter(Context context, List<NewsInfo> goodsList)
    {
        mContext = context;
        mGoodsList = goodsList;
    }

    // 获取列表项的个数
    public int getItemCount()
    {

        return mGoodsList.size();
    }

    // 创建列表项的视图持有者
    public ViewHolder onCreateViewHolder(ViewGroup vg, int viewType)
    {

        // 根据布局文件item_staggered.xml生成视图对象
        View v = LayoutInflater.from(mContext).inflate(R.layout.item_staggered, vg, false);
        return new ItemHolder(v);
    }

    // 绑定列表项的视图持有者
    public void onBindViewHolder(ViewHolder vh, final int position)
    {

        ItemHolder holder = (ItemHolder) vh;
        holder.iv_pic.setImageResource(mGoodsList.get(position).pic_id);
        holder.tv_title.setText(mGoodsList.get(position).title);
//        LayoutParams params = holder.ll_item.getLayoutParams();
//        params.height = new Random().nextInt(100);
//        if (params.height < 60) {
//            params.height = 60;
//        }
//        // 很奇怪，setLayoutParams对瀑布流网格不起作用，只能用setHeight
//        holder.tv_title.setHeight(params.height);

        // 列表项的点击事件需要自己实现
        holder.ll_item.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                if (mOnItemClickListener != null) {
                    mOnItemClickListener.onItemClick(v, position);
                }
            }
        });
        // 列表项的长按事件需要自己实现
        holder.ll_item.setOnLongClickListener(new OnLongClickListener()
        {

            @Override
            public boolean onLongClick(View v) {
                if (mOnItemLongClickListener != null) {
                    mOnItemLongClickListener.onItemLongClick(v, position);
                }
                return true;
            }
        });
    }

    // 获取列表项的类型
    public int getItemViewType(int position) {
        return 0;
    }

    // 获取列表项的编号
    public long getItemId(int position) {
        return position;
    }

    // 定义列表项的视图持有者
    public class ItemHolder extends ViewHolder {
        public LinearLayout ll_item; // 声明列表项的线性布局
        public ImageView iv_pic; // 声明列表项图标的图像视图
        public TextView tv_title; // 声明列表项标题的文本视图

        public ItemHolder(View v) {
            super(v);
            ll_item = v.findViewById(R.id.ll_item);
            iv_pic = v.findViewById(R.id.iv_pic);
            tv_title = v.findViewById(R.id.tv_title);
        }
    }

    // 声明列表项的点击监听器对象
    private OnItemClickListener mOnItemClickListener;

    public void setOnItemClickListener(OnItemClickListener listener) {
        this.mOnItemClickListener = listener;
    }

    // 声明列表项的长按监听器对象
    private OnItemLongClickListener mOnItemLongClickListener;

    public void setOnItemLongClickListener(OnItemLongClickListener listener) {
        this.mOnItemLongClickListener = listener;
    }

    // 处理列表项的点击事件
    public void onItemClick(View view, int position) {
        String desc = String.format("您点击了第%d项，商品名称是%s", position + 1,
                mGoodsList.get(position).title);
        Toast.makeText(mContext, desc, Toast.LENGTH_SHORT).show();
    }

    // 处理列表项的长按事件
    public void onItemLongClick(View view, int position) {
        String desc = String.format("您长按了第%d项，商品名称是%s", position + 1,
                mGoodsList.get(position).title);
        Toast.makeText(mContext, desc, Toast.LENGTH_SHORT).show();
    }

}