1-- menu layout
 <?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    >
    <item
        android:id="@+id/searchbar"
        android:title="Search"
        app:actionViewClass="android.widget.SearchView"
        app:showAsAction="always"

        ></item>
    <item android:id="@+id/Home"
        android:icon="@drawable/home"
        android:title="Home"
        app:showAsAction="ifRoom"/>
    <item android:id="@+id/Add"
        android:icon="@drawable/add"
        android:title="Add"
        app:showAsAction="ifRoom"/>
    <item android:id="@+id/setting"
        android:icon="@drawable/settings"
        android:title="Setting"
        app:showAsAction="ifRoom"/>


</menu>

2- menu code


 @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.mainmenu, menu);

        SearchView sv=(SearchView) menu.findItem(R.id.searchbar).getActionView();
        SearchManager sm=(SearchManager) getSystemService(Context.SEARCH_SERVICE);
        sv.setSearchableInfo(sm.getSearchableInfo(getComponentName()));
        sv.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                Toast.makeText(getApplicationContext(),query,Toast.LENGTH_LONG).show();
                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                return false;
            }
        });
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle item selection
        switch (item.getItemId()) {
            case R.id.Home:
                Toast.makeText(this,"Home",Toast.LENGTH_LONG).show();
                return true;
            case R.id.Add:
                Toast.makeText(this,"Add",Toast.LENGTH_LONG).show();
                return true;
            case R.id.setting:
                Toast.makeText(this,"Seeting",Toast.LENGTH_LONG).show();
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }