RecyclerFlexboxLayoutManagerDemo【使用FlexboxLayoutManager实现流式布局】

前言

FlexboxLayout是一个Google 开源的库项目，它将CSS Flexible Box Layout Module的类似功能引入Android。

这里只记录FlexboxLayoutManager搭配RecyclerView实现流式布局的实现方式，至于FlexboxLayout的独立使用以及相关资料，请阅读《参考资料》。

效果图

代码分析

将FlexboxLayoutManager理解为RecyclerView的一种manager，比如LinearLayoutManager等。

        //设置布局管理器

        FlexboxLayoutManager flexboxLayoutManager = new FlexboxLayoutManager(MainActivity.this);

        //flexDirection 属性决定主轴的方向（即项目的排列方向）。类似 LinearLayout 的 vertical 和 horizontal。

        flexboxLayoutManager.setFlexDirection(FlexDirection.ROW);//主轴为水平方向，起点在左端。

        //flexWrap 默认情况下 Flex 跟 LinearLayout 一样，都是不带换行排列的，但是flexWrap属性可以支持换行排列。

        flexboxLayoutManager.setFlexWrap(FlexWrap.WRAP);//按正常方向换行

        //justifyContent 属性定义了项目在主轴上的对齐方式。

        flexboxLayoutManager.setJustifyContent(JustifyContent.FLEX_START);//交叉轴的起点对齐。

        mRecyclerView.setLayoutManager(flexboxLayoutManager);

使用步骤

一、项目组织结构图

注意事项：

1、导入类文件后需要change包名以及重新import R文件路径

2、 Values目录下的文件（strings.xml、dimens.xml、colors.xml等），如果项目中存在，则复制里面的内容，不要整个覆盖

二、导入步骤

（1）在build.gradle中引用recyclerview【版本号和appcompat保持一致】和Flexboxlayout

apply plugin: 'com.android.application'

android {

    compileSdkVersion 27

    defaultConfig {

        applicationId "com.why.project.recyclerflexboxlayoutmanagerdemo"

        minSdkVersion 16

        targetSdkVersion 27

        versionCode 1

        versionName "1.0"

        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

    }

    buildTypes {

        release {

            minifyEnabled false

            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'

        }

    }

}

dependencies {

    implementation fileTree(dir: 'libs', include: ['*.jar'])

    implementation 'com.android.support:appcompat-v7:27.1.1'

    implementation 'com.android.support.constraint:constraint-layout:1.1.2'

    testImplementation 'junit:junit:4.12'

    androidTestImplementation 'com.android.support.test:runner:1.0.2'

    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'

    //RecyclerView

    compile "com.android.support:recyclerview-v7:27.1.1"

    //FlexboxLayout

    implementation 'com.google.android:flexbox:1.0.0'

}

（2）在项目中实现Recyclerview基本数据展现

1、创建Bean类

package com.why.project.recyclerflexboxlayoutmanagerdemo.bean;

import java.util.Date;

/**

 * Created by HaiyuKing

 * Used 搜索历史记录bean

 */

public class SearchHistoryBean {

    private String searchTitle;//搜索的标题

    private Date searchDate;//搜索的时间（如果重新搜索了的话，只需要更新搜索时间即可，不需要添加）

    public String getSearchTitle() {

        return searchTitle;

    }

    public void setSearchTitle(String searchTitle) {

        this.searchTitle = searchTitle;

    }

    public Date getSearchDate() {

        return searchDate;

    }

    public void setSearchDate(Date searchDate) {

        this.searchDate = searchDate;

    }

}

SearchHistoryBean.java

2、创建Adapter以及item的布局文件

package com.why.project.recyclerflexboxlayoutmanagerdemo.adapter;

import android.content.Context;

import android.support.v7.widget.RecyclerView;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.LinearLayout;

import android.widget.TextView;

import com.why.project.recyclerflexboxlayoutmanagerdemo.R;

import com.why.project.recyclerflexboxlayoutmanagerdemo.bean.SearchHistoryBean;

import java.util.ArrayList;

/**

 * Created by HaiyuKing

 * Used 搜索记录列表适配器

 */

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

    /**上下文*/

    private Context myContext;

    /**频道集合*/

    private ArrayList<SearchHistoryBean> listitemList;

    /**

     * 构造函数

     */

    public SearchHistoryAdapter(Context context, ArrayList<SearchHistoryBean> itemlist) {

        myContext = context;

        listitemList = itemlist;

    }

    /**

     * 获取总的条目数

     */

    @Override

    public int getItemCount() {

        return listitemList.size();

    }

    /**

     * 创建ViewHolder

     */

    @Override

    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View view = LayoutInflater.from(myContext).inflate(R.layout.searchhistory_list_item, parent, false);

        ItemViewHolder itemViewHolder = new ItemViewHolder(view);

        return itemViewHolder;

    }

    /**

     * 声明grid列表项ViewHolder*/

    static class ItemViewHolder extends RecyclerView.ViewHolder

    {

        public ItemViewHolder(View view)

        {

            super(view);

            listItemLayout = (LinearLayout) view.findViewById(R.id.listitem_layout);

            mTitle = (TextView) view.findViewById(R.id.tv_title);

        }

        LinearLayout listItemLayout;

        TextView mTitle;

    }

    /**

     * 将数据绑定至ViewHolder

     */

    @Override

    public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int index) {

        //判断属于列表项还是上拉加载区域

        if(viewHolder instanceof ItemViewHolder){

            SearchHistoryBean searchHistoryBean = listitemList.get(index);

            final ItemViewHolder itemViewHold = ((ItemViewHolder)viewHolder);

            itemViewHold.mTitle.setText(searchHistoryBean.getSearchTitle());

            //如果设置了回调，则设置点击事件

            if (mOnItemClickLitener != null)

            {

                itemViewHold.listItemLayout.setOnClickListener(new View.OnClickListener() {

                    @Override

                    public void onClick(View view) {

                        int position = itemViewHold.getLayoutPosition();//在增加数据或者减少数据时候，position和index就不一样了

                        mOnItemClickLitener.onItemClick(itemViewHold.listItemLayout, position);

                    }

                });

            }

        }

    }

    /**

     * 添加Item--用于动画的展现*/

    public void addItem(int position,SearchHistoryBean listitemBean) {

        listitemList.add(position,listitemBean);

        notifyItemInserted(position);

    }

    /**

     * 删除Item--用于动画的展现*/

    public void removeItem(int position) {

        listitemList.remove(position);

        notifyItemRemoved(position);

    }

    /*=====================添加OnItemClickListener回调================================*/

    public interface OnItemClickLitener

    {

        void onItemClick(View view, int position);

    }

    private OnItemClickLitener mOnItemClickLitener;

    public void setOnItemClickLitener(OnItemClickLitener mOnItemClickLitener)

    {

        this.mOnItemClickLitener = mOnItemClickLitener;

    }

}

SearchHistoryAdapter.java

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout

    xmlns:android="http://schemas.android.com/apk/res/android"

    android:id="@+id/listitem_layout"

    android:layout_width="wrap_content"

    android:layout_height="wrap_content"

    android:orientation="vertical"

    android:padding="5dp"

    android:layout_marginTop="8dp"

    android:layout_marginLeft="8dp"

    android:layout_marginRight="8dp"

    android:background="@drawable/searchhistory_item_bg">

    <TextView

        android:id="@+id/tv_title"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="标题"

        android:textSize="14sp"

        android:textColor="#333333"

        android:layout_gravity="center"/>

</LinearLayout>

searchhistory_list_item.xml

列表项布局文件中用到了背景drawable文件

<?xml version="1.0" encoding="utf-8"?>

<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle">

    <!-- 填充-->

    <solid android:color="#00000000"/>

    <!-- 描边 -->

    <stroke

        android:width="1dp"

        android:color="#7F7F7F" />

    <!-- 圆角 -->

    <corners

        android:radius="2dp" />

</shape>

searchhistory_item_bg.xml

3、在Activity布局文件中引用Recyclerview控件

<?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:orientation="vertical"

    android:background="#ffffff">

    <TextView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="历史记录"/>

    <!-- RecyclerView列表 -->

    <android.support.v7.widget.RecyclerView

        android:id="@+id/recycler_view"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:cacheColorHint="#00000000"

        android:divider="@null"

        android:listSelector="#00000000"

        android:scrollbars="none"

        />

</LinearLayout>

三、使用方法

（1）Activity中使用如下

package com.why.project.recyclerflexboxlayoutmanagerdemo;

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;

import android.support.v7.widget.RecyclerView;

import android.view.View;

import android.widget.Toast;

import com.google.android.flexbox.FlexDirection;

import com.google.android.flexbox.FlexWrap;

import com.google.android.flexbox.FlexboxLayoutManager;

import com.google.android.flexbox.JustifyContent;

import com.why.project.recyclerflexboxlayoutmanagerdemo.adapter.SearchHistoryAdapter;

import com.why.project.recyclerflexboxlayoutmanagerdemo.bean.SearchHistoryBean;

import java.util.ArrayList;

import java.util.Calendar;

public class MainActivity extends AppCompatActivity {

    private RecyclerView mRecyclerView;

    private ArrayList<SearchHistoryBean> mSearchHistoryBeanArrayList;

    private SearchHistoryAdapter mSearchHistoryAdapter;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        initViews();

        initDatas();

        initEvents();

    }

    private void initViews() {

        mRecyclerView = findViewById(R.id.recycler_view);

    }

    private void initDatas() {

        //初始化集合

        mSearchHistoryBeanArrayList = new ArrayList<SearchHistoryBean>();

        String[] testDatas = new String[]{"牙刷","灭蚊器","移动空调","吸尘器","布衣柜","收纳箱 书箱","暑期美食满99减15","挂烫机","吸水拖把","反季特惠"};

        for(int i=0; i<testDatas.length;i++){

            SearchHistoryBean channelBean = new SearchHistoryBean();

            channelBean.setSearchTitle(testDatas[i]);

            //获取当前日期

            Calendar calendar = Calendar.getInstance();

            channelBean.setSearchDate(calendar.getTime());

            mSearchHistoryBeanArrayList.add(channelBean);

        }

        //设置布局管理器

        FlexboxLayoutManager flexboxLayoutManager = new FlexboxLayoutManager(MainActivity.this);

        //flexDirection 属性决定主轴的方向（即项目的排列方向）。类似 LinearLayout 的 vertical 和 horizontal。

        flexboxLayoutManager.setFlexDirection(FlexDirection.ROW);//主轴为水平方向，起点在左端。

        //flexWrap 默认情况下 Flex 跟 LinearLayout 一样，都是不带换行排列的，但是flexWrap属性可以支持换行排列。

        flexboxLayoutManager.setFlexWrap(FlexWrap.WRAP);//按正常方向换行

        //justifyContent 属性定义了项目在主轴上的对齐方式。

        flexboxLayoutManager.setJustifyContent(JustifyContent.FLEX_START);//交叉轴的起点对齐。

        mRecyclerView.setLayoutManager(flexboxLayoutManager);

        //设置适配器

        if(mSearchHistoryAdapter == null){

            //设置适配器

            mSearchHistoryAdapter = new SearchHistoryAdapter(this, mSearchHistoryBeanArrayList);

            mRecyclerView.setAdapter(mSearchHistoryAdapter);

            //添加分割线

            //设置添加删除动画

            //调用ListView的setSelected(!ListView.isSelected())方法，这样就能及时刷新布局

            mRecyclerView.setSelected(true);

        }else{

            mSearchHistoryAdapter.notifyDataSetChanged();

        }

    }private void initEvents() {

        //列表适配器的点击监听事件

        mSearchHistoryAdapter.setOnItemClickLitener(new SearchHistoryAdapter.OnItemClickLitener() {

            @Override

            public void onItemClick(View view, int position) {

                Toast.makeText(MainActivity.this, mSearchHistoryBeanArrayList.get(position).getSearchTitle(), Toast.LENGTH_SHORT).show();

            }

        });

    }

}

效果图：

（2）如果在Adapter中添加以下代码，效果图则会发生变化（原理请阅读《参考资料》）【这段代码更适合用于图片展示，这里是搜索记录文本展现，不太合适】

package com.why.project.recyclerflexboxlayoutmanagerdemo.adapter;

import android.content.Context;

import android.support.v7.widget.RecyclerView;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.LinearLayout;

import android.widget.TextView;

import com.google.android.flexbox.AlignSelf;

import com.google.android.flexbox.FlexboxLayoutManager;

import com.why.project.recyclerflexboxlayoutmanagerdemo.R;

import com.why.project.recyclerflexboxlayoutmanagerdemo.bean.SearchHistoryBean;

import java.util.ArrayList;

/**

 * Created by HaiyuKing

 * Used 搜索记录列表适配器

 */

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

    /**上下文*/

    private Context myContext;

    /**频道集合*/

    private ArrayList<SearchHistoryBean> listitemList;

    /**

     * 构造函数

     */

    public SearchHistoryAdapter(Context context, ArrayList<SearchHistoryBean> itemlist) {

        myContext = context;

        listitemList = itemlist;

    }

    /**

     * 获取总的条目数

     */

    @Override

    public int getItemCount() {

        return listitemList.size();

    }

    /**

     * 创建ViewHolder

     */

    @Override

    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View view = LayoutInflater.from(myContext).inflate(R.layout.searchhistory_list_item, parent, false);

        ItemViewHolder itemViewHolder = new ItemViewHolder(view);

        return itemViewHolder;

    }

    /**

     * 声明grid列表项ViewHolder*/

    static class ItemViewHolder extends RecyclerView.ViewHolder

    {

        public ItemViewHolder(View view)

        {

            super(view);

            listItemLayout = (LinearLayout) view.findViewById(R.id.listitem_layout);

            mTitle = (TextView) view.findViewById(R.id.tv_title);

        }

        LinearLayout listItemLayout;

        TextView mTitle;

    }

    /**

     * 将数据绑定至ViewHolder

     */

    @Override

    public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int index) {

        //判断属于列表项还是上拉加载区域

        if(viewHolder instanceof ItemViewHolder){

            SearchHistoryBean searchHistoryBean = listitemList.get(index);

            final ItemViewHolder itemViewHold = ((ItemViewHolder)viewHolder);

            itemViewHold.mTitle.setText(searchHistoryBean.getSearchTitle());

            ViewGroup.LayoutParams lp = itemViewHold.listItemLayout.getLayoutParams();

            if (lp instanceof FlexboxLayoutManager.LayoutParams) {

                FlexboxLayoutManager.LayoutParams flexboxLp =

                        (FlexboxLayoutManager.LayoutParams) itemViewHold.listItemLayout.getLayoutParams();

                flexboxLp.setFlexGrow(1.0f);

                flexboxLp.setAlignSelf(AlignSelf.FLEX_END);

            }

            //如果设置了回调，则设置点击事件

            if (mOnItemClickLitener != null)

            {

                itemViewHold.listItemLayout.setOnClickListener(new View.OnClickListener() {

                    @Override

                    public void onClick(View view) {

                        int position = itemViewHold.getLayoutPosition();//在增加数据或者减少数据时候，position和index就不一样了

                        mOnItemClickLitener.onItemClick(itemViewHold.listItemLayout, position);

                    }

                });

            }

        }

    }

    /**

     * 添加Item--用于动画的展现*/

    public void addItem(int position,SearchHistoryBean listitemBean) {

        listitemList.add(position,listitemBean);

        notifyItemInserted(position);

    }

    /**

     * 删除Item--用于动画的展现*/

    public void removeItem(int position) {

        listitemList.remove(position);

        notifyItemRemoved(position);

    }

    /*=====================添加OnItemClickListener回调================================*/

    public interface OnItemClickLitener

    {

        void onItemClick(View view, int position);

    }

    private OnItemClickLitener mOnItemClickLitener;

    public void setOnItemClickLitener(OnItemClickLitener mOnItemClickLitener)

    {

        this.mOnItemClickLitener = mOnItemClickLitener;

    }

}

效果图

混淆配置

无

参考资料

google/flexbox-layout

Android FlexboxLayout 聪明的UI布局

Android可伸缩布局－FlexboxLayout(支持RecyclerView集成)

Google 开源的 Android 排版库：FlexboxLayout

项目demo下载地址

https://github.com/haiyuKing/RecyclerFlexboxLayoutManagerDemo