想在activity中进行fragment的设置和替换。setDefaultFragment()方法中，使用transaction.add(R.id.layFrame, MapsFragment.newInstance("map","map"));
语句则应用闪退。注释掉此语句则正常运行。

应用截图

xml

Activity

public class MainActivity extends AppCompatActivity
        implements BottomNavigationBar.OnTabSelectedListener{

    private ArrayList fragments;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //底部导航栏对象
        BottomNavigationBar bottomNavigationBar
                = (BottomNavigationBar) findViewById(R.id.bottom_navigation_bar);
        //设置样式、颜色
        bottomNavigationBar.setBackgroundStyle(BottomNavigationBar.BACKGROUND_STYLE_STATIC);
        bottomNavigationBar
                .setActiveColor(R.color.colorPrimary)
                .setInActiveColor("#FFFFFF")
                .setBarBackgroundColor("#ECECEC");
        //添加导航项
        bottomNavigationBar
                .addItem(new BottomNavigationItem(R.drawable.ic_location_on_white_24dp, "Location"))
                .addItem(new BottomNavigationItem(R.drawable.ic_tracks_on_white_24dp, "Tracks"))
                .setFirstSelectedPosition(0)
                .initialise();
        //获取fragment列表，设定默认fragment
        fragments = getFragments();
        setDefaultFragment();
        //监听
        bottomNavigationBar.setTabSelectedListener(this);

    }

    private ArrayList getFragments() {
        ArrayList fragments = new ArrayList<>();
        fragments.add(MapsFragment.newInstance("Map","Map"));
        fragments.add(TracksFragment.newInstance(3));
        return fragments;
    }

    private void setDefaultFragment(){
        FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
        transaction.add(R.id.layFrame, MapsFragment.newInstance("map","map"));
        transaction.addToBackStack(null);
        transaction.commit();
    }

    @Override
    void init() {

    }

    @Override
    public void onTabSelected(int position) {
    }

    @Override
    public void onTabUnselected(int position) {
    }

    @Override
    public void onTabReselected(int position) {
    }
}