前段時間公司移動端App新增一個模塊，類似美團團購的功能，首頁有個類似美團的分頁菜單的功能，用過美團和餓了么的app的童鞋應該清楚這一功能。首頁菜單可以分頁切換，類似我們的banner廣告切換效果，只不過只能手動切換。所以整個分頁效果，我們可以采用Viewpager實現，里面的菜單項我們則可以采用RecyclerView實現，動態改變里面的菜單項，以后產品汪要改需求也是一兩行代碼能搞定的事，是不是很機智。所以今天我們這個首頁分頁菜單效果，可以采用ViewPager+RecyclerView實現，思路既然已經有了，那我們就開整吧。首先我們先看下實現的效果圖。

最終實現效果

美團首頁分頁菜單

餓了么首頁分頁菜單

首頁布局文件，分頁指示器是單獨封裝的一個控件，后面會把代碼貼出來
activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              xmlns:app="http://schemas.android.com/apk/res-auto"
              android:id="@+id/home_entrance"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:orientation="vertical">

    <android.support.v4.view.ViewPager
        android:id="@+id/main_home_entrance_vp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

    <com.stx.xhb.meituancategorydemo.widget.IndicatorView
        android:id="@+id/main_home_entrance_indicator"
        android:layout_width="match_parent"
        android:layout_height="32dp"
        android:layout_marginLeft="16dp"
        android:layout_gravity="bottom"
        android:layout_marginRight="16dp"
        app:gravity="0"
        app:indicatorColor="#668b8989"
        app:indicatorColorSelected="#FF5722"
        app:indicatorWidth="6"/>

</LinearLayout>

ViewPager中的子控件RecyclerView
item_home_entrance_vp.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
                                        android:layout_width="match_parent"
                                        android:layout_height="wrap_content"/>

接下來就是RecyclerView的菜單項的布局文件
item_home_entrance.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
             android:layout_width="match_parent"
             android:layout_height="match_parent">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center_horizontal"
        android:orientation="vertical"
        android:padding="6dp">

        <ImageView
            android:id="@+id/entrance_image"
            android:layout_width="wrap_content"
            android:layout_height="0dp"
            android:layout_margin="2dp"
            android:layout_weight="1"
            android:scaleType="fitCenter"/>

        <TextView
            android:id="@+id/entrance_name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="2dp"
            android:singleLine="true"
            android:textColor="#80000000"
            android:textSize="12dp"/>
    </LinearLayout>

    <View
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@drawable/selector_trans_divider"/>

</FrameLayout>

布局都創建好了，接下來我們一起來看看里面的具體實現代碼了。由于我們的菜單項有一個icon和名稱name，為了方便管理，我們可以創建一個菜單項實體類ModelHomeEntrance.class

/**
 * Author: Mr.xiao on 2017/5/23
 *
 * @mail:xhb_199409@163.com
 * @github:https://github.com/xiaohaibin
 * @describe:菜單項實體類
 */
public class ModelHomeEntrance {
    private String name = "";
    private int image;

    public ModelHomeEntrance(String name, int image) {
        this.image = image;
        this.name = name;
    }


    public int getImage() {
        return image;
    }

    public String getName() {
        return name;
    }

}

由于我們分頁效果是以ViewPager實現的，所以我們要創建一個ViewPager的適配器，CagegoryViewPagerAdapter.Class

package com.stx.xhb.meituancategorydemo.adapter;

import android.support.v4.view.PagerAdapter;
import android.view.View;
import android.view.ViewGroup;

import java.util.List;

/**
 * Created by jxnk25 on 2016/9/21.
 *
 * @link https://xiaohaibin.github.io/
 * @email： xhb_199409@163.com
 * @github: https://github.com/xiaohaibin
 * @description：  首頁分類ViewPager適配器
 */
public class CagegoryViewPagerAdapter extends PagerAdapter {

    private List<View> mViewList;
    public CagegoryViewPagerAdapter(List<View> mViewList) {
        this.mViewList = mViewList;
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        container.removeView(mViewList.get(position));
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        container.addView(mViewList.get(position));
        return (mViewList.get(position));
    }

    @Override
    public int getCount() {
        if (mViewList == null)
            return 0;
        return mViewList.size();
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view == object;
    }
}

ViewPager的適配器有了，我們還得再創建一個RecyclerView的菜單項列表適配器，EntranceAdapter.Class

package com.stx.xhb.meituancategorydemo.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.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

import com.stx.xhb.meituancategorydemo.R;
import com.stx.xhb.meituancategorydemo.model.ModelHomeEntrance;
import com.stx.xhb.meituancategorydemo.utils.ScreenUtil;

import java.util.List;

/**
 * Author: Mr.xiao on 2017/5/23
 *
 * @mail:xhb_199409@163.com
 * @github:https://github.com/xiaohaibin
 * @describe: 首頁分頁菜單項列表適配器
 */
public class EntranceAdapter extends RecyclerView.Adapter<EntranceAdapter.EntranceViewHolder> {

    private List<ModelHomeEntrance> mDatas;

    /**
     * 頁數下標,從0開始(通俗講第幾頁)
     */
    private int mIndex;

    /**
     * 每頁顯示最大條目個數
     */
    private int mPageSize;

    private Context mContext;

    private final LayoutInflater mLayoutInflater;

    private List<ModelHomeEntrance> homeEntrances;

    public EntranceAdapter(Context context, List<ModelHomeEntrance> datas, int index, int pageSize) {
        this.mContext = context;
        this.homeEntrances = datas;
        mPageSize = pageSize;
        mDatas = datas;
        mIndex = index;
        mLayoutInflater = LayoutInflater.from(context);

    }

    @Override
    public EntranceViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        return new EntranceViewHolder(mLayoutInflater.inflate(R.layout.item_home_entrance, null));
    }

    @Override
    public void onBindViewHolder(EntranceViewHolder holder, final int position) {
        /**
         * 在給View綁定顯示的數據時，計算正確的position = position + mIndex * mPageSize，
         */
        final int pos = position + mIndex * mPageSize;
        holder.entranceNameTextView.setText(homeEntrances.get(pos).getName());
        holder.entranceIconImageView.setImageResource(homeEntrances.get(pos).getImage());
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                ModelHomeEntrance entrance = homeEntrances.get(pos);
                // TODO: 2017/5/24 點擊事件處理
            }
        });
    }

    @Override
    public int getItemCount() {
        return mDatas.size() > (mIndex + 1) * mPageSize ? mPageSize : (mDatas.size() - mIndex * mPageSize);
    }

    @Override
    public long getItemId(int position) {
        return position + mIndex * mPageSize;
    }

    class EntranceViewHolder extends RecyclerView.ViewHolder {

        private TextView entranceNameTextView;
        private ImageView entranceIconImageView;

        public EntranceViewHolder(View itemView) {
            super(itemView);
            entranceIconImageView = (ImageView) itemView.findViewById(R.id.entrance_image);
            entranceNameTextView = (TextView) itemView.findViewById(R.id.entrance_name);
            LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, (int) ((float) ScreenUtil.getScreenWidth() / 4.0f));
            itemView.setLayoutParams(layoutParams);
        }
    }
}

最后就是我們的MainActivity的代碼實現了，我們整體的思路其實就是需要根據首頁菜單項的數據源進行分頁顯示，首頁確定單頁菜單顯示數量，總數除以單頁顯示數量取整就是顯示頁數，我們再根據頁數來創建RecyclerView將其添加到ViewPager的適配器中，下面就讓我們一起來看看具體是如何的。

package com.stx.xhb.meituancategorydemo;

import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.LinearLayout;

import com.stx.xhb.meituancategorydemo.adapter.CagegoryViewPagerAdapter;
import com.stx.xhb.meituancategorydemo.adapter.EntranceAdapter;
import com.stx.xhb.meituancategorydemo.model.ModelHomeEntrance;
import com.stx.xhb.meituancategorydemo.utils.ScreenUtil;
import com.stx.xhb.meituancategorydemo.widget.IndicatorView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    public static final int HOME_ENTRANCE_PAGE_SIZE = 10;//首頁菜單單頁顯示數量
    private ViewPager entranceViewPager;
    private LinearLayout homeEntranceLayout;
    private List<ModelHomeEntrance> homeEntrances;
    private IndicatorView entranceIndicatorView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initData();
        initView();
        init();
    }


    private void initView() {
        homeEntranceLayout = (LinearLayout) findViewById(R.id.home_entrance);
        entranceViewPager = (ViewPager) findViewById(R.id.main_home_entrance_vp);
        entranceIndicatorView = (IndicatorView) findViewById(R.id.main_home_entrance_indicator);
    }


    private void initData() {
        homeEntrances = new ArrayList<>();
        homeEntrances.add(new ModelHomeEntrance("美食", R.mipmap.ic_category_0));
        homeEntrances.add(new ModelHomeEntrance("電影", R.mipmap.ic_category_1));
        homeEntrances.add(new ModelHomeEntrance("酒店住宿", R.mipmap.ic_category_2));
        homeEntrances.add(new ModelHomeEntrance("生活服務", R.mipmap.ic_category_3));
        homeEntrances.add(new ModelHomeEntrance("KTV", R.mipmap.ic_category_4));
        homeEntrances.add(new ModelHomeEntrance("旅游", R.mipmap.ic_category_5));
        homeEntrances.add(new ModelHomeEntrance("學習培訓", R.mipmap.ic_category_6));
        homeEntrances.add(new ModelHomeEntrance("汽車服務", R.mipmap.ic_category_7));
        homeEntrances.add(new ModelHomeEntrance("攝影寫真", R.mipmap.ic_category_8));
        homeEntrances.add(new ModelHomeEntrance("休閑娛樂", R.mipmap.ic_category_10));
        homeEntrances.add(new ModelHomeEntrance("麗人", R.mipmap.ic_category_11));
        homeEntrances.add(new ModelHomeEntrance("運動健身", R.mipmap.ic_category_12));
        homeEntrances.add(new ModelHomeEntrance("大保健", R.mipmap.ic_category_13));
        homeEntrances.add(new ModelHomeEntrance("團購", R.mipmap.ic_category_14));
        homeEntrances.add(new ModelHomeEntrance("景點", R.mipmap.ic_category_16));
        homeEntrances.add(new ModelHomeEntrance("全部分類", R.mipmap.ic_category_15));
    }

    private void init() {
        LinearLayout.LayoutParams layoutParams12 = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, (int) ((float) ScreenUtil.getScreenWidth() / 2.0f));

        //首頁菜單分頁
        FrameLayout.LayoutParams entrancelayoutParams = new FrameLayout.LayoutParams(FrameLayout.LayoutParams.MATCH_PARENT, (int) ((float) ScreenUtil.getScreenWidth() / 2.0f + 70));
        homeEntranceLayout.setLayoutParams(entrancelayoutParams);
        entranceViewPager.setLayoutParams(layoutParams12);
        LayoutInflater inflater = LayoutInflater.from(this);
        //將RecyclerView放至ViewPager中：
        int pageSize = HOME_ENTRANCE_PAGE_SIZE;
        //一共的頁數等于 總數/每頁數量，并取整。
        int pageCount = (int) Math.ceil(homeEntrances.size() * 1.0 / pageSize);
        List<View> viewList = new ArrayList<View>();
        for (int index = 0; index < pageCount; index++) {
            //每個頁面都是inflate出一個新實例
            RecyclerView recyclerView = (RecyclerView) inflater.inflate(R.layout.item_home_entrance_vp, entranceViewPager, false);
            recyclerView.setLayoutParams(layoutParams12);
            recyclerView.setLayoutManager(new GridLayoutManager(MainActivity.this, 5));
            EntranceAdapter entranceAdapter = new EntranceAdapter(MainActivity.this, homeEntrances, index, HOME_ENTRANCE_PAGE_SIZE);
            recyclerView.setAdapter(entranceAdapter);
            viewList.add(recyclerView);
        }
        CagegoryViewPagerAdapter adapter = new CagegoryViewPagerAdapter(viewList);
        entranceViewPager.setAdapter(adapter);
        entranceIndicatorView.setIndicatorCount(entranceViewPager.getAdapter().getCount());
        entranceIndicatorView.setCurrentIndicator(entranceViewPager.getCurrentItem());
        entranceViewPager.addOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                entranceIndicatorView.setCurrentIndicator(position);
            }
        });
    }
}

以上就是實現首頁分頁菜單效果的主要實現代碼，這種分頁菜單效果在我們的應用中也比較常見，說不定啥時候公司產品汪就拿手機過來讓你照著美團之類實現這種效果，demo地址如下，如果幫到了你，可以點個start，支持一個哦~~~~~~~
https://github.com/xiaohaibin/MeiTuanCategaryDemo