我有问题。我有一个带有底部导航栏的应用程序-逻辑是在MainActivity中完成的，每个页面都是使用片段制作的。当我单击底部的那些按钮之一时，将打开另一个片段。在其中两个中，我嵌套了片段。在每个按钮中，我都有一个按钮，单击时会打开另一个片段（就像一种弹出窗口一样，该片段覆盖了屏幕的大部分区域，但应用栏除外）。打开弹出片段时，除了BACK BUTTON之外，一切都很好。当我单击它时，整个应用程序关闭。我试图从MainActivity中的堆栈中删除该弹出片段，但仍然无济于事。因此，通过应用程序的路径就是这样：
favourite_fragment-> favourite_sub_cars_fragment-> pop_up_fragment
您对如何使其正常工作有什么建议？在这里，我发布了一些必要的代码和一张按顺序排列的图像，以帮助您了解整个应用程序的逻辑。
public class MainActivity extends AppCompatActivity {
private ViewPager viewPager;
private BottomNavigationView navigation;
private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
= new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.navigation_main_page:
// close stack_search_fragment:
getSupportFragmentManager().popBackStack("stack_search_fragment", FragmentManager.POP_BACK_STACK_INCLUSIVE);
// close stack_favourite_sub_cars_fragment (-- IT ACTUALLY DOESN'T WORK --)
getSupportFragmentManager().popBackStack("stack_favourite_sub_cars_fragment", FragmentManager.POP_BACK_STACK_INCLUSIVE);
viewPager.setCurrentItem(0);
return true;
case R.id.navigation_favourite:
// close stack_search_fragment:
getSupportFragmentManager().popBackStack("stack_search_fragment", FragmentManager.POP_BACK_STACK_INCLUSIVE);
// close stack_favourite_sub_cars_fragment (-- IT ACTUALLY DOESN'T WORK --)
getSupportFragmentManager().popBackStack("stack_favourite_sub_cars_fragment", FragmentManager.POP_BACK_STACK_INCLUSIVE);
viewPager.setCurrentItem(1);
return true;
case R.id.navigation_search:
// close stack_search_fragment:
getSupportFragmentManager().popBackStack("stack_search_fragment", FragmentManager.POP_BACK_STACK_INCLUSIVE);
// close stack_favourite_sub_cars_fragment (-- IT ACTUALLY DOESN'T WORK --)
getSupportFragmentManager().popBackStack("stack_favourite_sub_cars_fragment", FragmentManager.POP_BACK_STACK_INCLUSIVE);
viewPager.setCurrentItem(2);
return true;
case R.id.navigation_profile:
// close stack_search_fragment:
getSupportFragmentManager().popBackStack("stack_search_fragment", FragmentManager.POP_BACK_STACK_INCLUSIVE);
// close stack_favourite_sub_cars_fragment (-- IT ACTUALLY DOESN'T WORK --)
getSupportFragmentManager().popBackStack("stack_favourite_sub_cars_fragment", FragmentManager.POP_BACK_STACK_INCLUSIVE);
viewPager.setCurrentItem(3);
return true;
}
return false;
}
};
onClick（）方法：
@Override
public void onClick(View v)
{
try
{
Fragment newFragment = new PopUpFragment();
FragmentTransaction tr = getFragmentManager().beginTransaction();
tr.replace(R.id.fragmentContainerFavourite, newFragment);
tr.addToBackStack("stack_favourite_sub_cars_fragment");
tr.commit();
}
catch(Exception e)
{
e.printStackTrace();
}
}
fragment_favourite.xml：
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:id="@+id/fragmentContainerFavourite"
>
<android.support.design.widget.TabLayout
android:id="@+id/tabs_favourite"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?colorPrimary"
app:tabIndicatorColor="?colorAccent"
app:tabMode="fixed"
app:tabSelectedTextColor="@android:color/white"
app:tabTextColor="#ddd"/>
<android.support.v4.view.ViewPager
android:id="@+id/view_pager_favourite"
android:layout_width="match_parent"
android:layout_height="fill_parent"
android:layout_below="@id/tabs_favourite"
/>
</android.support.constraint.ConstraintLayout>
fragment_favourite_sub_cars.xml：
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView
xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/containerFavouriteCars"
>
<Button
android:id="@+id/button"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Go into pop-up fragment!"
android:layout_marginTop="45dp"
/>
</android.support.v4.widget.NestedScrollView>
pop_up_frgment.xml：
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
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:background="@color/white"
>
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginLeft="8dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
android:layout_marginRight="8dp"
android:layout_marginBottom="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:text="ONE CAR!"
android:textSize="20dp"/>
</android.support.constraint.ConstraintLayout>