如何使用设计库选项卡布局更改工具栏标题？答案

【问题标题】：How to change the toolbar title using design Library Tab Layout?如何使用设计库选项卡布局更改工具栏标题？
【发布时间】：2015-10-20 02:55:58
【问题描述】：

我正在使用支持 TabLayout 的设计库，我正在尝试在按下 Tab 或滑动 ViewPager 时更改工具栏的标题。但到目前为止无法获得任何成功。这是以下代码：-

public class ActivityHomePage extends AppCompatActivity {
    private TabLayout tabLayout;
    private ViewPager viewPager;
    Toolbar toolbar;
    DesignDemoPagerAdapter adapter;

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

        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setDisplayShowTitleEnabled(false);




        viewPager = (ViewPager) findViewById(R.id.viewpager);
        setupViewPager(viewPager);
      //  viewPager.getAdapter().getPageTitle();
        tabLayout = (TabLayout) findViewById(R.id.tablayout);
        tabLayout.setupWithViewPager(viewPager);
        setupTabIcons();


    }
    private int[] tabIcons = {

            R.drawable.ic_action_star,
            R.drawable.ic_action_heart,
            R.drawable.ic_action_square
    };
    private void setupViewPager(ViewPager viewPager) {
        adapter = new DesignDemoPagerAdapter(getSupportFragmentManager());

        adapter.addFrag(new FragmentStar(), "star");
        adapter.addFrag(new FragmentHeart(), "heart");
        adapter.addFrag(new FragmentSquare(), "square");
        viewPager.setAdapter(adapter);



    }



    @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;
    }

    private void setupTabIcons() {
        tabLayout.getTabAt(0).setIcon(tabIcons[0]);
        tabLayout.getTabAt(1).setIcon(tabIcons[1]);
        tabLayout.getTabAt(2).setIcon(tabIcons[2]);

    }


    @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();

        switch (id) {
            case android.R.id.home:
                mDrawerLayout.openDrawer(GravityCompat.START);
                return true;
            case R.id.action_settings:
                return true;
        }

        return super.onOptionsItemSelected(item);
    }




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

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

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

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

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

        }

        @Override
        public CharSequence getPageTitle(int position) {


            return null;
        }
    }

}

【问题讨论】：

您在哪里更改代码中的标题？调用setTitle() 将更改您活动中Toolbar 的标题。

标签： android material-design android-design-library android-tablayout

【解决方案1】：

我终于可以做到了，可能对某人有帮助，所以这里是上面的答案：-

  /** Tab & PageViewer Controller**/
        tabLayout = (TabLayout) findViewById(R.id.tablayout);
        tabLayout.addTab(tabLayout.newTab().setIcon(R.drawable.ic_action_star));
        tabLayout.addTab(tabLayout.newTab().setIcon(R.drawable.ic_action_heart));
        tabLayout.addTab(tabLayout.newTab().setIcon(R.drawable.ic_action_square));

        tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
       // setupTabIcons();

      viewPager = (ViewPager) findViewById(R.id.viewpager);
        pAdapter = new PagerAdapter
                (getSupportFragmentManager(), tabLayout.getTabCount());
        viewPager.setAdapter(pAdapter);
        toolbar.setTitle("Same Page");
        viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
        tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                switch(tab.getPosition()) {
                    case 0:
                        viewPager.setCurrentItem(0);
                        toolbar.setTitle("Fragment Star");
                        break;
                    case 1:
                        viewPager.setCurrentItem(1);
                        toolbar.setTitle("Fragment Heart");
                        break;
                    case 2:
                        viewPager.setCurrentItem(2);
                        toolbar.setTitle("Fragment Squae");
                        break;

                    default:

                        viewPager.setCurrentItem(tab.getPosition());
                        toolbar.setTitle("Fragment Star");
                        break;
                }



            }

            @Override
            public void onTabUnselected(TabLayout.Tab tab) {

            }

            @Override
            public void onTabReselected(TabLayout.Tab tab) {

            }
        });


    }
/** **/
 public class PagerAdapter extends FragmentStatePagerAdapter {
        int mNumOfTabs;

        public PagerAdapter(FragmentManager fm, int NumOfTabs) {
            super(fm);
            this.mNumOfTabs = NumOfTabs;
        }

        @Override
        public Fragment getItem(int position) {

            switch (position) {
                case 0:
                    FragmentStar tab0 = new FragmentStar();
                    return tab0;
                case 1:
                    FragmentHeart tab1 = new FragmentHeart();
                    return tab1;
                case 2:
                    FragmentSquare tab2 = new FragmentSquare();
                    return tab2;

                default:
                    return null;
            }
        }

        @Override
        public int getCount() {
            return mNumOfTabs;
        }
    }

【讨论】：

对我不起作用 - 没有更改标题/。无论如何，我只是通过插入您的代码在工作室中遇到了一个错误，因为 viewPager 应该被声明为 final
又试了一次，这次我注意到你使用了toolbar.setTitle()。这导致更改了应用程序名称而不是选项卡标题。
现在可以了。我必须更改您的代码才能使用 tabLayout.getTabAt(position).setText("Fragment " + position) 才能工作。感谢您指出正确的方向
我在发表评论时这样做了，但由于某种原因，我发现它并没有增加它。我现在又试了一次。

【解决方案2】：

万一有人来这里寻求帮助。这是@Khanna's Code 的更简单更好的版本

根据您的选项卡名称在您的类中初始化一个数组。

CharSequence 标题[] = {"Star","Heart", "Square"};

现在就用吧。

toolbar.setTitle(titles[tab.getPosition()]);

这是修改后的代码。

 CharSequence titles[] = {"Star","Heart", "Square"};


/** Tab & PageViewer Controller**/
    tabLayout = (TabLayout) findViewById(R.id.tablayout);
    tabLayout.addTab(tabLayout.newTab().setIcon(R.drawable.ic_action_star));
    tabLayout.addTab(tabLayout.newTab().setIcon(R.drawable.ic_action_heart));
    tabLayout.addTab(tabLayout.newTab().setIcon(R.drawable.ic_action_square));

    tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
   // setupTabIcons();

  viewPager = (ViewPager) findViewById(R.id.viewpager);
    pAdapter = new PagerAdapter
            (getSupportFragmentManager(), tabLayout.getTabCount());
    viewPager.setAdapter(pAdapter);
    toolbar.setTitle("Same Page");
    viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
    tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {

                    viewPager.setCurrentItem(0);


                  //Now just set title using your array
                    toolbar.setTitle(titles[tab.getPosition()]);


            }



        }

        @Override
        public void onTabUnselected(TabLayout.Tab tab) {

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }
    });
}

 public class PagerAdapter extends FragmentStatePagerAdapter{
    int mNumOfTabs;
    public PagerAdapter(FragmentManager fm, int NumOfTabs) {
        super(fm);
        this.mNumOfTabs = NumOfTabs;
    }

    @Override
    public Fragment getItem(int position) {

        switch (position) {
            case 0:
                FragmentStar tab0 = new FragmentStar();
                return tab0;
            case 1:
                FragmentHeart tab1 = new FragmentHeart();
                return tab1;
            case 2:
                FragmentSquare tab2 = new FragmentSquare();
                return tab2;

            default:
                return null;
        }
    }

    @Override
    public int getCount() {
        return mNumOfTabs;
    }
}

【讨论】：

【解决方案3】：

由于不推荐使用 setOnTabSelectedListener，因此您可以像此示例一样使用

 viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
    tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {
            switch (tab.getPosition()) {
                case 0:
                    viewPager.setCurrentItem(0);
                    getSupportActionBar().setTitle("Recipes");
                    break;
                case 1:
                    viewPager.setCurrentItem(1);
                    getSupportActionBar().setTitle("Categories");
                    break;
                case 2:
                    viewPager.setCurrentItem(2);
                    getSupportActionBar().setTitle("Favorites");
                    break;

                default:
                    viewPager.setCurrentItem(tab.getPosition());
                    getSupportActionBar().setTitle("Cook Book");
                    break;
            }
        }

        @Override
        public void onTabUnselected(TabLayout.Tab tab) {

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }
    });

【讨论】：