Add image to top navigation bar in Android Lollipop

Question

I want to know the ways of adding an image to Top Navigation bar in Android lollipop instead of the title of the application.

Like in the image below :

Answer 1

The Toolbar is a ViewGroup, so you can just add a child ImageView to it:

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    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">
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:src="@drawable/image"/>
    </android.support.v7.widget.Toolbar>

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