Why is app name not showing in Toolbar in android?

Question

The app name is not showing in the app-bar. Its white. i don't know why. please help. It was showing before. then i made lots of changes now is unable to fix it

In main activity

....
<android.support.v7.widget.Toolbar
    android:id="@+id/my_toolbar"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    android:background="?attr/colorPrimary"
    android:elevation="4dp"
    android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
    android:visibility="visible"
    app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />


  ....

</RelativeLayout>

In styles

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
</style>

In android manifest

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/Theme.AppCompat.Light.NoActionBar"
    >
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

public class MainActivity extends AppCompatActivity  {

    public static final String LOG_TAG = MainActivity.class.getName();

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

        Toolbar myToolbar = (Toolbar) findViewById(R.id.my_toolbar);
        setSupportActionBar(myToolbar);

        // Set the content of the activity to use the activity_main.xml layout file
        setContentView(R.layout.activity_main);

        // Find the view pager that will allow the user to swipe between fragments
        ViewPager viewPager = (ViewPager) findViewById(R.id.viewpager);

        // Create an adapter that knows which fragment should be shown on each page
        ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());

        // Set the adapter onto the view pager
        viewPager.setAdapter(adapter);

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

        // Connect the tab layout with the view pager. This will
        //   1. Update the tab layout when the view pager is swiped
        //   2. Update the view pager when a tab is selected
        //   3. Set the tab layout's tab names with the view pager's adapter's titles
        //      by calling onPageTitle()
        tabLayout.setupWithViewPager(viewPager);

    }
}

Answer 1

Either add this in your java file. It sets the true for show title bar property which makes it visible.

getSupportActionBar().setDisplayShowTitleEnabled(true);

Or add this in your xml under toolbar element

app:title="@string/app_name"

app is used to denote properties included in support library widgets.

Most important you should have app_name string in your string.xml file.

For Title in Centre

You have to design your own custom layout for action bar and set it to that. How to set title in centre in ActionBar?