Всем привет! Сможет ли кто-нибудь подсказать?
Есть приложение: на главной активности фрагмент (BiografyClass с fragment_bigrafy.xml ), в этом фрагменте 2 кнопки, при нажатии на которые открываются еще фрагменты. В примере при нажатии на button открывается SettingsFragment, а при нажатии на button2 открывается AboutFragment. При переходе на следующие фрагменты(SettingsFragment или AboutFragment) и при нажатии кнопки "Back" во втором фрагменте приложение
закрывается , а хотелось бы, чтобы возвращалась на предыдущий фрагмент - BiografyClass.
Как из второго фрагмента вернуться на первый? Метод addToBackStack(""); прописан.
Никак не могу разобраться, как вернуться на предыдущий фрагмент с помощью кнопки "Назад" на устройстве.
Код главной активности:
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public class MainActivity extends AppCompatActivity {
private TextView mTextMessage;
private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
= new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
Fragment fragment = null;
Class fragmentClass = null;
int id = item.getItemId();
if (id == R.id.biografy) {
fragmentClass = BiografyClass.class;
} else if (id == R.id.photo) {
fragmentClass = PhotoFragment.class;
} else if (id == R.id.settings) {
fragmentClass = SettingsFragment.class;
}
else if (id == R.id.about) {
fragmentClass = AboutFragment.class;
}
try {
fragment = (Fragment) fragmentClass.newInstance();
} catch (Exception e) {
e.printStackTrace();
}
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction().replace(R.id.fragment, fragment).commit();
setTitle(item.getTitle());
return true;
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTextMessage = (TextView) findViewById(R.id.message);
BottomNavigationView navigation = (BottomNavigationView) findViewById(R.id.navigation);
navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
}
}
Activity_main.xml(тут фрагмент):
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<?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:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.example.butam.biografy4.MainActivity">
<LinearLayout
android:id="@+id/content"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1">
<fragment
android:id="@+id/fragment"
android:name="com.example.butam.biografy4.BiografyClass"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center_horizontal"
/>
</LinearLayout>
<android.support.design.widget.BottomNavigationView
android:id="@+id/navigation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:background="?android:attr/windowBackground"
app:menu="@menu/navigation" />
</LinearLayout>
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public class BiografyClass extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
@Nullable Bundle savedInstanceState) {
View rootView =
inflater.inflate(R.layout.fragment_biografy, container, false);
return rootView;
}
}
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<?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:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.example.butam.biografy4.MainActivity">
<LinearLayout
android:id="@+id/content"
android:layout_width="match_parent"
android:orientation="vertical"
android:layout_height="0dp"
android:layout_weight="1">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" />
<fragment
android:id="@+id/fragment1"
android:name="com.example.butam.biografy4.BiografyEmblemClass"
android:layout_width="396dp"
android:layout_height="match_parent"
android:layout_weight="1" />
</LinearLayout>
</LinearLayout>
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public class BiografyEmblemClass extends Fragment implements View.OnClickListener {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
@Nullable Bundle savedInstanceState) {
View rootView =
inflater.inflate(R.layout.biografy_emblem_fragment, container, false);
Button button = (Button) rootView.findViewById(R.id.button);
Button button2 = (Button) rootView.findViewById(R.id.button2);
button.setOnClickListener(this);
button2.setOnClickListener(this);
return rootView;
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.button:
Fragment settingsFragment = new SettingsFragment();
FragmentTransaction trans=getFragmentManager().beginTransaction();
trans.replace(R.id.content, settingsFragment);
trans.addToBackStack("");
trans.commit();
break;
case R.id.button2:
Fragment aboutFragment = new AboutFragment();
FragmentTransaction trans2 = getFragmentManager().beginTransaction();
trans2.replace(R.id.content, aboutFragment);
trans2.addToBackStack("");
trans2.commit();
break;
}
}
}
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<?xml version="1.0" encoding="utf-8"?>
<ScrollView 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:id="@+id/scroll"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="500dp">
<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="8dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginTop="8dp"
android:text="@string/main_text"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.055" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="8dp"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:layout_marginTop="8dp"
android:text="@string/biografy_emblem"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.203" />
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button"
android:onClick="onClick"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_marginBottom="8dp"
app:layout_constraintTop_toTopOf="parent"
android:layout_marginTop="8dp"
android:layout_marginRight="8dp"
app:layout_constraintRight_toRightOf="parent"
android:layout_marginLeft="8dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintHorizontal_bias="0.257"
app:layout_constraintVertical_bias="0.672" />
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button2"
android:onClick="onClick"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_marginBottom="8dp"
app:layout_constraintTop_toTopOf="parent"
android:layout_marginTop="8dp"
android:layout_marginRight="8dp"
app:layout_constraintRight_toRightOf="parent"
android:layout_marginLeft="8dp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintHorizontal_bias="0.832"
app:layout_constraintVertical_bias="0.655" />
</android.support.constraint.ConstraintLayout>
</LinearLayout>
</ScrollView>
