Here is the top answer How to add “UP” back button in fragment
<android.support.v7.widget.Toolbar
android:id="@+id/toolbarId"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:navigationIcon="?attr/homeAsUpIndicator"/>
You can use app:navigationIcon="?attr/homeAsUpIndicator" for that back navigation icon.
<android.support.v7.widget.Toolbar
android:id="@+id/toolbarId"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:navigationIcon="?attr/homeAsUpIndicator"/>
For navigation:
Toolbar toolbar = (ToolBar) getActivity().findViewById(R.id.toolbarId);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
getActivity().onBackPressed();
}
});