How to get Toolbar from fragment?

You need to cast your activity from getActivity() to AppCompatActivity first. Here's an example:

((AppCompatActivity) getActivity()).getSupportActionBar().setTitle();

The reason you have to cast it is because getActivity() returns a FragmentActivity and you need an AppCompatActivity

In Kotlin:

(activity as AppCompatActivity).supportActionBar?.title = "My Title"

In case fragments should have custom view of ToolBar you can implement ToolBar for each fragment separately.

add ToolBar into fragment_layout:

<android.support.v7.widget.Toolbar    xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/toolbar"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:background="?attr/colorPrimaryDark"/>

find it in fragment:

@Override    public View onCreateView(LayoutInflater inflater, ViewGroup container,                             Bundle savedInstanceState) {        View view = inflater.inflate(R.layout.fragment, container, false);        Toolbar toolbar = (Toolbar) view.findViewById(R.id.toolbar);        //set toolbar appearance        toolbar.setBackground(R.color.material_blue_grey_800);        //for crate home button        AppCompatActivity activity = (AppCompatActivity) getActivity();        activity.setSupportActionBar(toolbar);        activity.getSupportActionBar().setDisplayHomeAsUpEnabled(true);}

menu listener could be created two ways:override onOptionsItemSelected in your fragment:

@Overridepublic boolean onOptionsItemSelected(MenuItem item) {    switch(item.getItemId()){        case android.R.id.home:            getActivity().onBackPressed();    }    return super.onOptionsItemSelected(item);}

or set listener for toolbar when create it in onCreateView():

toolbar.setOnMenuItemClickListener(new Toolbar.OnMenuItemClickListener() {            @Override            public boolean onMenuItemClick(MenuItem menuItem) {                return false;            }        });

You have two choices to get Toolbar in fragment

First one

Toolbar toolbar = (Toolbar) getActivity().findViewById(R.id.toolbar);

and second one

Toolbar toolbar = ((MainActivity) getActivity()).mToolbar;