java - L'application plante après avoir utilisé la méthode add de l'objet FragmentTransaction sous Android
Je souhaite définir et remplacer des fragments dans l'activité. Dans la méthode setDefaultFragment(), si vous utilisez l'instruction transaction.add(R.id.layFrame, MapsFragment.newInstance("map","map"));
, l'application plantera. Commentez cette déclaration et elle fonctionnera normalement.
Capture d'écran de l'application
xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.example.tourguide.activity.MainActivity">
<FrameLayout android:id="@+id/layFrame"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1" />
<com.ashokvarma.bottomnavigation.BottomNavigationBar
android:id="@+id/bottom_navigation_bar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom" />
</LinearLayout>
Activité
public class MainActivity extends AppCompatActivity
implements BottomNavigationBar.OnTabSelectedListener{
private ArrayList<Fragment> 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<Fragment> getFragments() {
ArrayList<Fragment> 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) {
}
}