java - The application crashes after using the add method of the FragmentTransaction object in Android
I want to set and replace fragments in the activity. In the setDefaultFragment() method, use the transaction.add(R.id.layFrame, MapsFragment.newInstance("map","map"));
statement to cause a crash. Comment out this statement and it will run normally.
Application screenshot
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>
Activity
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) {
}
}