User this in your xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/colorPrimary"
android:elevation="4dp"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" />
<FrameLayout
android:id="@+id/frame"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
and then in the activity onCreate(); add this
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_toolbar);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
toolbar.setTitle("YOUR_TITLE");
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
This line will add the arrow at the left corner of the toolbar
getSupportActionBar().setDisplayHomeAsUpEnabled(true);