我在MainActivity.java中有一个底部导航栏,其中包含3个片段。我想将其中一个片段设置为默认打开应用程序启动时自动打开的页面。我该怎么做?这是我的MainActivity.java代码:
public class MainActivity extends AppCompatActivity {
private static final String TAG = MainActivity.class.getSimpleName();
private BottomNavigationView bottomNavigation;
private Fragment fragment;
private android.support.v4.app.FragmentManager fragmentManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bottomNavigation = (BottomNavigationView)findViewById(R.id.bottom_navigation);
bottomNavigation.inflateMenu(R.menu.bottom_menu);
fragmentManager = getSupportFragmentManager();
bottomNavigation.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
Fragment selectedFragment = null;
int id = item.getItemId();
switch (id){
case R.id.intros:
fragment = new IntrosFragment();
break;
case R.id.menus:
fragment = new MenusFragment();
break;
case R.id.infos:
fragment = new InfosFragment();
break;
}
FragmentTransaction transaction = fragmentManager.beginTransaction();
transaction.replace(R.id.main_container, fragment).commit();
return true;
}
});
}
}
这是一个例子中的片段(它们都是相同的):
public class IntrosFragment extends Fragment {
public IntrosFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_intro, container, false);
// Inflate the layout for this fragment
TextView txt = (TextView) rootView.findViewById(R.id.introtv);
Typeface font = Typeface.createFromAsset(getActivity().getAssets(), "fonts/naskh.ttf");
txt.setTypeface(font);
return rootView;
}
}
我该怎么办?