Android开发之TabLayout实现顶部菜单

在Android开发中，经常要使用顶部菜单，如网易新闻、今日头条等，实现顶部菜单以前是ViewPager配合PagerTabStrip来实现，但Android 5.0以后，推荐大家使用MD中的TabLayout来实现，很简单哦~~

开发环境：Android Studio

开发步骤

• 1、在 build.gradle 导入 com.android.support:design:22.2.1
• 2、Activity布局

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <android.support.design.widget.TabLayout
        android:id="@+id/tabs"
        android:layout_width="match_parent"
        android:layout_height="48dp" //菜单高度
        android:background="#1FBCD2" //菜单条的背景
        app:tabIndicatorColor="#ff0000" //菜单指示器的颜色
        app:tabMode="scrollable" //菜单可以滚动
        app:tabPaddingEnd="20dp" 
        app:tabPaddingStart="20dp" //菜单之间的间距
        app:tabSelectedTextColor="#FFFFFF" //菜单选中时的颜色
        app:tabTextColor="#000000"> //菜单未选中时的颜色
    </android.support.design.widget.TabLayout>

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

</LinearLayout>

• 3、Activity代码

public class MainActivity extends Activity {

    private TabLayout mTabLayout;
    private ViewPager mViewPager;
    private LayoutInflater mInflater;
    private List<String> mTitleList = new ArrayList<String>();//页卡标题集合
    private View view1, view2, view3, view4, view5, view6, view7, view8;//页卡视图
    private List<View> mViewList = new ArrayList<>();//页卡视图集合

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

        mViewPager = (ViewPager) findViewById(R.id.vp_view);
        mTabLayout = (TabLayout) findViewById(R.id.tabs);
        mInflater = LayoutInflater.from(this);

        view1 = mInflater.inflate(R.layout.content, null);
        view2 = mInflater.inflate(R.layout.content, null);
        view3 = mInflater.inflate(R.layout.content, null);
        view4 = mInflater.inflate(R.layout.content, null);
        view5 = mInflater.inflate(R.layout.content, null);
        view6 = mInflater.inflate(R.layout.content, null);
        view7 = mInflater.inflate(R.layout.content, null);
        view8 = mInflater.inflate(R.layout.content, null);
        //添加页卡视图
        mViewList.add(view1);
        mViewList.add(view2);
        mViewList.add(view3);
        mViewList.add(view4);
        mViewList.add(view5);
        mViewList.add(view6);
        mViewList.add(view7);
        mViewList.add(view8);
       //添加页卡标题
        mTitleList.add("头条");
        mTitleList.add("热点");
        mTitleList.add("本地");
        mTitleList.add("财经");
        mTitleList.add("科技");
        mTitleList.add("教育");
        mTitleList.add("体育");
        mTitleList.add("笑话");
       //添加tab选项卡，默认第一个选中
        mTabLayout.addTab(mTabLayout.newTab().setText(mTitleList.get(0)), true);
        mTabLayout.addTab(mTabLayout.newTab().setText(mTitleList.get(1)));
        mTabLayout.addTab(mTabLayout.newTab().setText(mTitleList.get(2)));
        mTabLayout.addTab(mTabLayout.newTab().setText(mTitleList.get(3)));
        mTabLayout.addTab(mTabLayout.newTab().setText(mTitleList.get(4)));
        mTabLayout.addTab(mTabLayout.newTab().setText(mTitleList.get(5)));
        mTabLayout.addTab(mTabLayout.newTab().setText(mTitleList.get(6)));
        mTabLayout.addTab(mTabLayout.newTab().setText(mTitleList.get(7)));


        MyPagerAdapter mAdapter = new MyPagerAdapter(mViewList);
       //给ViewPager设置适配器
        mViewPager.setAdapter(mAdapter);

       //将TabLayout和ViewPager关联起来
        mTabLayout.setupWithViewPager(mViewPager);
       //给Tabs设置适配器
        mTabLayout.setTabsFromPagerAdapter(mAdapter);
    }

    //ViewPager适配器
    class MyPagerAdapter extends PagerAdapter {
        private List<View> mViewList;

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

        @Override
        public int getCount() {
            return mViewList.size();//页卡数
        }

        @Override
        public boolean isViewFromObject(View view, Object object) {
            return view == object;//官方推荐写法
        }

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

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

        @Override
        public CharSequence getPageTitle(int position) {
            return mTitleList.get(position);//页卡标题
        }

    }

}

• 4、实现效果如下

TabLayout.png

• 5、注意点
  如果真的按上面一字不差走下来的话，会发现TabLayout在ViewPager滑动的时候会出现菜单文字闪烁的现象。这个应该是版本的bug，想解决的话使用22.0里没有bug的版本（compile 'com.android.support:design:22.2.0'）或者升级到23.x