RecyclerFlexboxLayoutManagerDemo【使用FlexboxLayoutManager实现流式布局】

版权声明：本文为HaiyuKing原创文章，转载请注明出处！

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