Android Design新控件之TabLaout（二），仿微信实现App底部Tab布局

TabLayout的两种常见设计布局：

• 顶部标签页（如今日头条，知乎）
• 底部菜单栏（如微信主界面）

其中上一篇文章中讲到了Android Design新控件之TabLaout（一），快速打造一个滑动标签页，接着接着举例使用TabLayout+ViewPager来简单实现一个类似于微信等App底部菜单栏布局，按照惯例，我们先来看看简单的效果图：

1、和上一篇文章一样，我们需要在应用的build.gradle中添加support:design支持库

compile 'com.android.support:design:23.1.1'

2、创建activity_main.xml文件，在布局文件中添加TabLayout和ViewPager

<?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.support.v4.view.ViewPager
        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1" />

    <View
        android:layout_width="match_parent"
        android:layout_height="1px"
        android:background="#bebebe" />

    <android.support.design.widget.TabLayout
        android:id="@+id/tablayout"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:background="@android:color/white" />
</LinearLayout>

3、创建适配器FragmentAdapter.class

package com.per.tablayoutdome;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;

import java.util.List;

/**
 * 适配器
 * Created by lijuan on 2016/8/23.
 */
public class FragmentAdapter extends FragmentStatePagerAdapter {
    public List<Fragment> list;
    private List<String> titles;

    /**
     * 构造方法
     */
    public FragmentAdapter(FragmentManager fm, List<Fragment> list, List<String> titles) {
        super(fm);
        this.list = list;
        this.titles = titles;
    }

    /**
     * 返回显示的Fragment总数
     */
    @Override
    public int getCount() {
        return list.size();
    }

    /**
     * 返回要显示的Fragment的某个实例
     */
    @Override
    public Fragment getItem(int position) {
        return list.get(position);
    }

    /**
     * 返回每个Tab的标题
     */
    @Override
    public CharSequence getPageTitle(int position) {
        return titles.get(position);
    }
}

4、选项卡页面TabFragment.class

package com.per.tablayoutdome;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

/**
 * Created by lijuan on 2016/8/23.
 */
public class TabFragment extends Fragment {
    private TextView textView;

    public static TabFragment newInstance(int index){
        Bundle bundle = new Bundle();
        bundle.putInt("index", 'A' + index);
        TabFragment fragment = new TabFragment();
        fragment.setArguments(bundle);
        return fragment;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.tab_fragment, null);
        textView = (TextView) view.findViewById(R.id.text);
        textView.setText(String.valueOf((char) getArguments().getInt("index")));
        return view;
    }
}

5、选项卡布局文件tab_fragment.xml

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

    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:textColor="@color/colorAccent"
        android:textSize="75dp" />
</RelativeLayout>

6、主页面中MainActivity.class

package com.per.tablayoutdome;

import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;
/**
 * 主页面
 * Created by lijuan on 2016/8/23.
 */
public class MainActivity extends AppCompatActivity {
    private String[] titles = new String[]{"微信", "通讯录", "发现", "我"};
    private TabLayout mTabLayout;
    private ViewPager mViewPager;
    private FragmentAdapter adapter;
    //ViewPage选项卡页面集合
    private List<Fragment> mFragments;
    //Tab标题集合
    private List<String> mTitles;
    /**
     * 图片数组
     */
    private int[] mImgs=new int[]{R.drawable.selector_tab_weixin, R.drawable.selector_tab_friends, R.drawable.selector_tab_find,
            R.drawable.selector_tab_me};

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

        mViewPager = (ViewPager) findViewById(R.id.viewpager);
        mTabLayout = (TabLayout) findViewById(R.id.tablayout);

        mTitles = new ArrayList<>();
        for (int i = 0; i < 4; i++) {
            mTitles.add(titles[i]);
        }

        mFragments = new ArrayList<>();
        for (int i = 0; i < mTitles.size(); i++) {
            mFragments.add(TabFragment.newInstance(i));
        }
        adapter = new FragmentAdapter(getSupportFragmentManager(), mFragments, mTitles);
        mViewPager.setAdapter(adapter);//给ViewPager设置适配器
        mTabLayout.setupWithViewPager(mViewPager);//将TabLayout和ViewPager关联起来

        mTabLayout.setSelectedTabIndicatorHeight(0);
        for (int i = 0; i < mTitles.size(); i++) {
            //获得到对应位置的Tab
            TabLayout.Tab itemTab = mTabLayout.getTabAt(i);
            if (itemTab != null) {
                //设置自定义的标题
                itemTab.setCustomView(R.layout.item_tab);
                TextView textView = (TextView) itemTab.getCustomView().findViewById(R.id.tv_name);
                textView.setText(mTitles.get(i));
                ImageView imageView= (ImageView) itemTab.getCustomView().findViewById(R.id.iv_img);
                imageView.setImageResource(mImgs[i]);
            }
        }
        mTabLayout.getTabAt(0).getCustomView().setSelected(true);
    }

}

其中需要注意几点：
（1）mTabLayout.setSelectedTabIndicatorHeight(0);是为了不显示tab底部的横线；
（2）系统默认的TabLayout模式是MODE_FIXED，让底部tab布局不可滑动；
（3）itemTab.setCustomView(R.layout.item_tab);用于设置自定义的标题

本片文章主要是的功能是TabLayout的Title使用自定义Layout，以上的代码和上一篇文章差不多，下面我们根据需求自己添加Layout文件。

7、item_tab.xml

<?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:gravity="center"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/iv_img"
        android:layout_width="26dp"
        android:layout_height="26dp" />

    <TextView
        android:id="@+id/tv_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@color/selector_blue" />

</LinearLayout>

好了，本篇文章已经全部写完了，存在总结不到位的地方还望指导，感谢^_^

源码下载