将设备设置为水平时，防止tablayout返回默认值

Question

您好我正在使用以下教程处理视图页面模板： http://www.androidhive.info/2015/09/android-material-design-working-with-tabs/

我能够为每个标签添加过滤器以及更改颜色，但我遇到了一个奇怪的问题。带有fab的模板和我添加了一个功能，无论何时按下晶圆厂，它都会添加额外的选项卡并重新加载tablayout。这种方法效果很好。但是，当我水平倾斜设备时，视图会回到只有一个选项卡（应用程序打开时的状态。）任何想法为什么会发生这种情况？我尝试了一些事情，包括完成活动并重新启动它但没有运气。提前谢谢。

JAVA：

package com.example.reasults.materialpagerdesign;

import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;

import java.security.cert.CertificateParsingException;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import android.app.Activity;
import com.example.reasults.materialpagerdesign.OneFragment;

public class MainActivity extends AppCompatActivity {

    private Toolbar toolbar;
    private TabLayout tabLayout;
    private ViewPager viewPager;
    private LinkedList<String> tabs = new LinkedList<String>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        if (tabs.size() < 1) { tabs.add("ONE");};
        //if (tabs.size() == 2) {Log.i("TEST", "here");}

        setContentView(R.layout.activity_main);
        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        getSupportActionBar().setDisplayHomeAsUpEnabled(false);

        viewPager = (ViewPager) findViewById(R.id.viewpager);
        setupViewPager(viewPager);

        tabLayout = (TabLayout) findViewById(R.id.tabs);
        tabLayout.setupWithViewPager(viewPager);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
                tabs.add("Two");
                viewPager = (ViewPager) findViewById(R.id.viewpager);
                setupViewPager(viewPager);

                tabLayout = (TabLayout) findViewById(R.id.tabs);
                tabLayout.setupWithViewPager(viewPager);
                /*Log.i("TEST", Integer.toString(tabs.size()));
                tabs.add("Two");
                Log.i("TEST", Integer.toString(tabs.size()));
                Intent intent = new Intent(MainActivity.this, MainActivity.class);
                finish();
                startActivity(intent);*/
            }
        });

        viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                if (position == 0) {
                    toolbar.setBackgroundColor(getResources().getColor(R.color.colorPrimary));
                    tabLayout.setBackgroundColor(getResources().getColor(R.color.colorPrimary));
                }
                if (position == 1) {
                    toolbar.setBackgroundColor(Color.parseColor("#4DAC26"));
                    tabLayout.setBackgroundColor(Color.parseColor("#4DAC26"));
                }

            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });
    }

    private void setupViewPager(ViewPager viewPager) {
        ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
        //adapter.addFragment(new OneFragment(), "ONE");

        for (int i = 0; i < tabs.size(); i ++){
            adapter.addFragment(new OneFragment(), tabs.get(i));
        }
        viewPager.setAdapter(adapter);
    }

    private void setupViewPager2(ViewPager viewPager) {
        ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
        adapter.addFragment(new OneFragment(), "ONE");
        adapter.addFragment(new TwoFragment(), "Two");
        viewPager.setAdapter(adapter);
    }

    class ViewPagerAdapter extends FragmentPagerAdapter {
        private final List<Fragment> mFragmentList = new ArrayList<>();
        private final List<String> mFragmentTitleList = new ArrayList<>();

        public ViewPagerAdapter(FragmentManager manager) {
            super(manager);
        }

        @Override
        public Fragment getItem(int position) {
            return mFragmentList.get(position);
        }

        @Override
        public int getCount() {
            return mFragmentList.size();
        }

        public void addFragment(Fragment fragment, String title) {
            mFragmentList.add(fragment);
            mFragmentTitleList.add(title);
        }

        @Override
        public CharSequence getPageTitle(int position) {
            return mFragmentTitleList.get(position);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

XML：

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
    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:layout_width="match_parent"
    android:layout_height="match_parent" android:fitsSystemWindows="true"
    tools:context=".MainActivity">

    <android.support.design.widget.AppBarLayout android:layout_height="wrap_content"
        android:layout_width="match_parent" android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar android:id="@+id/toolbar"
            android:layout_width="match_parent" android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary" app:popupTheme="@style/AppTheme.PopupOverlay" />

        <android.support.design.widget.TabLayout
            android:id="@+id/tabs"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:tabMode="scrollable"
            app:tabGravity="fill"/>
    </android.support.design.widget.AppBarLayout>

    <android.support.v4.view.ViewPager
        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"  />

    <include layout="@layout/content_main" />

    <android.support.design.widget.FloatingActionButton android:id="@+id/fab"
        android:layout_width="wrap_content" android:layout_height="wrap_content"
        android:layout_gravity="bottom|end" android:layout_margin="@dimen/fab_margin"
        android:src="@android:drawable/ic_dialog_email" />

</android.support.design.widget.CoordinatorLayout>