简介

FragmentTabHost是support-v包下提供的用于集成和管理Fragment页面的组件。从4.0.3版本开始，谷歌就将选项卡TabHost、TabWidget替换为FragmentTabHost+LayoutInflatert,更方便搬砖的我们实现底部菜单切换页面的功能，如微信的页面切换。

我个人觉得用FragmentTabHost比ViewPager好用的地方是，前者没有预加载一说，与fragment一起使用清爽无比。

废话不多说，先来一张效果图

实例

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.gwt.testfragmenttabhost.MainActivity">

    <!--内容布局-->
    <FrameLayout
        android:id="@+id/fl_container"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"/>

    <View
        android:layout_width="match_parent"
        android:layout_height="0.5dp"
        android:background="@color/colord2d2d2"/>

    <!--标签切换-->
    <android.support.v4.app.FragmentTabHost
        android:id="@+id/fragment_tab"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <FrameLayout
            android:id="@+id/fl_fragment_tab"
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:layout_weight="0">

        </FrameLayout>

    </android.support.v4.app.FragmentTabHost>

</LinearLayout>

每个按钮的布局 tab_layout.xnl

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center_horizontal"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/image"
        android:layout_marginTop="6dp"
        android:layout_width="22dp"
        android:layout_height="22dp"
        android:layout_gravity="center_horizontal" />

    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="6dp"
        android:layout_marginBottom="6dp"
        android:textColor="@color/color3a3a3a" />
</LinearLayout>

创建4个fragment，对你来说肯定很简单，代码就不粘贴了，想看源码的文章最后有链接

图片的选择器

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/tab_icon_class_pre" android:state_focused="true" />
    <item android:drawable="@drawable/tab_icon_class_pre" android:state_selected="true" />
    <item android:drawable="@drawable/tab_icon_class" />
</selector>

MainActivity.class(精华所在)

public class MainActivity extends AppCompatActivity {

    private FrameLayout flContainer;
    private FragmentTabHost tabHost;
    private FrameLayout flTab;
    private String[] tabNames = {"首页", "题库", "课程", "我的"};
    private int[] imageButton = {R.drawable.tab_home_selector, R.drawable.tab_exercises_selector, R.drawable.tab_course_selector, R.drawable.tab_mine_selector};
    private Class[] fragmentArray = {OneFragment.class, TwoFragment.class, ThreeFragment.class, FourFragment.class};

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

    private void initView() {
        flContainer = findViewById(R.id.fl_container);
        tabHost = findViewById(R.id.fragment_tab);
        flTab = findViewById(R.id.fl_fragment_tab);
    }

    private void initData() {
        tabHost.setup(this, getSupportFragmentManager(), R.id.fl_container);

        for (int i = 0; i < tabNames.length; i++) {
                    // 给每一个Tabbutton设置图标、文字和内容
            TabHost.TabSpec tabSpec = tabHost.newTabSpec(tabNames[i]).setIndicator(getButtonView(i));
                    // 将Tabbutton加入进Tab选项卡中
            tabHost.addTab(tabSpec, fragmentArray[i], null);
                    //去掉分隔的竖线
            tabHost.getTabWidget().setShowDividers(LinearLayout.SHOW_DIVIDER_NONE);
        }
    }

    /**
     * 获取每一个选项
     * @param index
     * @return
     */
    public View getButtonView(int index) {
        View view = LayoutInflater.from(this).inflate(R.layout.tab_layout, null);
        ImageView imageView = view.findViewById(R.id.image);
        //设置图标
     imageView.setImageResource(imageButton[index]);
        TextView textView = view.findViewById(R.id.text);
        //设置文字
     textView.setText(tabNames[index]);
        return view;
    }
}

FragmentTabHost使用代码不多，对你来说是小 case 吧 ！！！！

想看代码的可以去这里https://github.com/G-youngboy/TestFragmentTabHost