android - 标签不显示 Tablayout + ViewPager

Question

选项卡内容已呈现，我可以在它们之间滑动，但选项卡未显示。

activity_home.xml(请注意我如何将 TabLayout 嵌套在 ViewPager 下，如 here 所述)

<?xml version="1.0" encoding="utf-8"?>

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main_activity_DrawerLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:context=".HomeActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <include
            android:id="@+id/tool_bar"
            layout="@layout/tool_bar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

        <android.support.v4.view.ViewPager
            android:id="@+id/pager"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1">
            <android.support.design.widget.TabLayout
                android:id="@+id/tabs"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="bottom"
                android:elevation="2dp" />
        </android.support.v4.view.ViewPager>

    </LinearLayout>
    <!-- The navigation drawer -->
    <include layout="@layout/navigation_drawer" />

</android.support.v4.widget.DrawerLayout>

HomeActivity.java

public class HomeActivity extends AppCompatActivity {

    // Declaring Your View and Variables

    Toolbar mToolbar;
    ViewPager mViewPager;
    ViewPagerAdapter mViewPagerAdapter;
    TabLayout mSlidingTabs;
    CharSequence mTabTitles[] = {"Home", "Events"};

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

        mToolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(mToolbar);

        initSlidingTabs();
    }

    private void initSlidingTabs() {
        mViewPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager(), mTabTitles);

        // Assigning ViewPager View and setting the mViewPagerAdapter
        mViewPager = (ViewPager) findViewById(R.id.pager);
        mViewPager.setAdapter(mViewPagerAdapter);

////也尝试了以下但没有任何改变 //mSlidingTabs = (TabLayout) findViewById(R.id.tabs); //mSlidingTabs.addTab(mSlidingTabs.newTab().setText("Tab 1")); //mSlidingTabs.addTab(mSlidingTabs.newTab().setText("Tab 2")); //mSlidingTabs.setupWithViewPager(mViewPager); }

ViewPagerAdapter.java

public class ViewPagerAdapter extends FragmentStatePagerAdapter {

    CharSequence mTabTitles[]; // This will Store the mTabTitles of the Tabs which are Going to be passed when ViewPagerAdapter is created

    // Build a Constructor and assign the passed Values to appropriate values in the class
    public ViewPagerAdapter(FragmentManager fm, CharSequence mTitles[]) {
        super(fm);

        this.mTabTitles = mTitles;
    }

    //This method return the fragment for the every position in the View Pager
    @Override
    public Fragment getItem(int position) {
        if(position == 0) // if the position is 0 we are returning the First tab
        {
            Tab1 tab1 = new Tab1();
            return tab1;
        }
        else             // As we are having 2 tabs if the position is now 0 it must be 1 so we are returning second tab
        {
            Tab2 tab2 = new Tab2();
            return tab2;
        }
    }

    // This method return the titles for the Tabs in the Tab Strip
    @Override
    public CharSequence getPageTitle(int position) {
        return mTabTitles[position];
    }

    // This method return the Number of tabs for the tabs Strip
    @Override
    public int getCount() {
        return mTabTitles.length;
    }
}

Tab1.java

public class Tab1 extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.tab_1,container,false);
        return v;
    }
}

Answer 1

我现在也有同样的问题。

通过在 ViewPager 中嵌套 TabLayout 来遵循 Google 的文档不工作。

按照 Google 的文档将 PagerTabStrip 嵌套在 ViewPager 中确实有效。

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解决方案

不要将TabLayout 嵌套在ViewPager 中。将它紧挨着 ViewPager 放置。