我有 2 個活動，其中單獨NavHostFragment托管 3 個片段，然后這 3 個片段顯示在我的活動布局ContainerView中。注意：我的 2 個活動名稱相同，使用相同的布局，唯一的區別是它們位于不同的目錄中，處理的任務略有不同。
最初，我計劃為應用程式使用所有片段，但現在，我決定在第一個版本中只使用一個片段，然后再處理其他片段，因為它的任務是一次處理所有片段
所以我想安全地洗掉底部導航視圖和其他兩個片段（第二個和第三個片段）。
已經，我最初嘗試通過洗掉這些片段并擦除與之相關的任何代碼來自己做這件事，但它出現了很多錯誤，所以我決定把它帶到這里看看是否有人可以以最安全的方式提供幫助我可以洗掉它們，以便我的第一個片段可以繼續運行而不會出現任何問題。
這是一個天氣應用程式，所以我會在第一個片段上收到當前城市的更新。我本應該收到關于第二個和第三個片段的每小時和每日更新，但我已經停止了我的計劃，現在我只想使用第一個片段。
以下是主要代碼：
活動\家庭活動：
public class HomeActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
private DrawerLayout drawer;
// Last update time, click sound, search button, search panel.
TextView timeField;
MediaPlayer player;
ImageView Search;
EditText textfield;
// For scheduling background image change(using constraint layout, start counting from dubai, down to statue of liberty.
ConstraintLayout constraintLayout;
public static int count = 0;
int[] drawable = new int[]{R.drawable.nyc, R.drawable.lofoten_islands, R.drawable.parque, R.drawable.moraine_lake, R.drawable.eiffel_tower,
R.drawable.whitehaven_beach, R.drawable.london, R.drawable.cape_town, R.drawable.burj_al_arab,R.drawable.atuh_beach};
Timer _t;
private WeatherDataViewModel viewModel;
private AppBarConfiguration appBarConfiguration;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
// use home activity layout.
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
// Allow activity to make use of the toolbar
drawer = findViewById(R.id.drawer_layout);
NavigationView navigationView = findViewById(R.id.nav_view);
navigationView.setNavigationItemSelectedListener(this);
// Hiding default Drawer fragment that has the BottomNavView
navigationView.getMenu().findItem(R.id.main_id).setVisible(false);
viewModel = new ViewModelProvider(this).get(WeatherDataViewModel.class);
// Trigger action to open & close navigation drawer
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(this, drawer, toolbar
, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.addDrawerListener(toggle);
toggle.syncState();
timeField = findViewById(R.id.textView9);
Search = findViewById(R.id.imageView4);
textfield = findViewById(R.id.textfield);
// find the id's of specific variables.
BottomNavigationView bottomNavigationView = findViewById(R.id.bottomNavigationView);
// host 3 fragments along with bottom navigation.
final NavHostFragment navHostFragment = (NavHostFragment) getSupportFragmentManager().findFragmentById(R.id.fragment);
assert navHostFragment != null;
final NavController navController = navHostFragment.getNavController();
// Make hourly & daily tab unusable
bottomNavigationView.setOnNavigationItemSelectedListener(item -> {
if (getSupportFragmentManager().getBackStackEntryCount() > 0) {
getSupportFragmentManager().popBackStack();
}
return false;
});
toggle.setToolbarNavigationClickListener(v -> {
// Enable the functionality of opening the side drawer, when the burger icon is clicked
toggle.setDrawerIndicatorEnabled(true);
navController.navigate(R.id.main_id);
});
// Passing each menu ID as a set of Ids because each
// menu should be considered as top level destinations.
// remove up button from all these fragments
appBarConfiguration = new AppBarConfiguration.Builder(
R.id.main_id) // remove up button from all these fragments >> Keep up button in R.id.nav_setting, R.id.nav_slideshow
.setOpenableLayout(drawer)
.build();
NavigationUI.setupActionBarWithNavController(this, navController, appBarConfiguration);
NavigationUI.setupWithNavController(navigationView, navController);
// navController.addOnDestinationChangedListener((controller, destination, arguments) -> navController.popBackStack(destination.getId(), false));
// navController.addOnDestinationChangedListener((controller, destination, arguments) -> {
// });
navController.addOnDestinationChangedListener((controller, destination, arguments) -> {
// Hide/show top search bar
if (destination.getId() == R.id.main_id) {
Search.setVisibility(View.VISIBLE);
textfield.setVisibility(View.VISIBLE);
} else {
Search.setVisibility(View.GONE);
textfield.setVisibility(View.GONE);
}
// Fragments that you want to show the back button
if (destination.getId() == R.id.about_id || destination.getId() == R.id.privacy_policy_id) {
// Disable the functionality of opening the side drawer, when the burger icon is clicked
toggle.setDrawerIndicatorEnabled(false);
}
});
// For scheduling background image change
constraintLayout = findViewById(R.id.layout);
constraintLayout.setBackgroundResource(R.drawable.nyc);
_t = new Timer();
_t.scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
// run on ui thread
runOnUiThread(() -> {
if (count < drawable.length) {
constraintLayout.setBackgroundResource(drawable[count]);
count = (count 1) % drawable.length;
}
});
}
}, 5000, 5000);
Search.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// make click sound when search button is clicked.
player = MediaPlayer.create(HomeActivity.this, R.raw.click);
player.start();
getWeatherData(textfield.getText().toString().trim());
// make use of some fragment's data
Fragment currentFragment = navHostFragment.getChildFragmentManager().getFragments().get(0);
if (currentFragment instanceof FirstFragment) {
FirstFragment firstFragment = (FirstFragment) currentFragment;
firstFragment.getWeatherData(textfield.getText().toString().trim());
} else if (currentFragment instanceof SecondFragment) {
SecondFragment secondFragment = (SecondFragment) currentFragment;
secondFragment.getWeatherData(textfield.getText().toString().trim());
} else if (currentFragment instanceof ThirdFragment) {
ThirdFragment thirdFragment = (ThirdFragment) currentFragment;
thirdFragment.getWeatherData(textfield.getText().toString().trim());
}
}
private void getWeatherData(String name) {
ApiInterface apiInterface = ApiClient.getClient().create(ApiInterface.class);
Call<Example> call = apiInterface.getWeatherData(name);
call.enqueue(new Callback<Example>() {
@Override
public void onResponse(@NonNull Call<Example> call, @NonNull Response<Example> response) {
try {
assert response.body() != null;
timeField.setVisibility(View.VISIBLE);
timeField.setText("First Updated:" " " response.body().getDt());
} catch (Exception e) {
timeField.setVisibility(View.GONE);
timeField.setText("First Updated: Unknown");
Log.e("TAG", "No City found");
Toast.makeText(HomeActivity.this, "No City found", Toast.LENGTH_SHORT).show();
}
}
@Override
public void onFailure(@NotNull Call<Example> call, @NotNull Throwable t) {
t.printStackTrace();
}
});
}
});
}
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.about_id:
getSupportFragmentManager().beginTransaction().replace(R.id.fragment,
new About()).commit();
break;
case R.id.privacy_policy_id:
getSupportFragmentManager().beginTransaction().replace(R.id.fragment,
new Privacy_Policy()).commit();
break;
}
drawer.closeDrawer(GravityCompat.START);
return true;
}
@Override
public void onBackPressed() {
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
// Open/close drawer animation
}
}
@Override
protected void onPause () {
super.onPause();
if (viewModel.getMediaPlayer() != null)
viewModel.getMediaPlayer().pause();
}
@Override
protected void onResume () {
super.onResume();
if (viewModel.getMediaPlayer() != null) {
viewModel.getMediaPlayer().start();
viewModel.getMediaPlayer().setLooping(true);
}
}
@Override
public boolean onSupportNavigateUp() {
final NavHostFragment navHostFragment = (NavHostFragment) getSupportFragmentManager().findFragmentById(R.id.fragment);
assert navHostFragment != null;
final NavController navController = navHostFragment.getNavController();
return NavigationUI.navigateUp(navController, appBarConfiguration)
|| super.onSupportNavigateUp(); // navigateUp tries to pop the backstack
}
}
天氣預報\家庭活動：
public class HomeActivity extends AppCompatActivity {
private DrawerLayout drawer;
// Last update time, click sound, search button, search panel.
TextView timeField;
MediaPlayer player;
ImageView Search;
ConstraintLayout searchbar;
EditText textfield;
// For scheduling background image change(using constraint layout, start counting from dubai, down to statue of liberty.
ConstraintLayout constraintLayout;
public static int count = 0;
int[] drawable = new int[]{R.drawable.nyc, R.drawable.lofoten_islands, R.drawable.parque, R.drawable.moraine_lake, R.drawable.eiffel_tower,
R.drawable.whitehaven_beach, R.drawable.london, R.drawable.cape_town, R.drawable.burj_al_arab, R.drawable.atuh_beach};
Timer _t;
private WeatherDataViewModel viewModel;
private AppBarConfiguration appBarConfiguration;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
// use home activity layout.
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
// Allow activity to make use of the toolbar
drawer = findViewById(R.id.drawer_layout);
NavigationView navigationView = findViewById(R.id.nav_view);
// host 3 fragments along with bottom navigation.
final NavHostFragment navHostFragment = (NavHostFragment) getSupportFragmentManager().findFragmentById(R.id.fragment);
assert navHostFragment != null;
final NavController navController = navHostFragment.getNavController();
// Passing each menu ID as a set of Ids because each
// menu should be considered as top level destinations.
// remove up button from all these fragments
appBarConfiguration = new AppBarConfiguration.Builder(
R.id.main_id) // remove up button from all these fragments >> Keep up button in R.id.nav_setting, R.id.nav_slideshow
.setOpenableLayout(drawer)
.build();
// Hiding default Drawer fragment that has the BottomNavView
navigationView.getMenu().findItem(R.id.main_id).setVisible(false);
viewModel = new ViewModelProvider(this).get(WeatherDataViewModel.class);
// Trigger action to open & close navigation drawer
ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(this, drawer, toolbar
, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.addDrawerListener(toggle);
toggle.syncState();
timeField = findViewById(R.id.textView9);
Search = findViewById(R.id.imageView4);
textfield = findViewById(R.id.textfield);
searchbar = findViewById(R.id.searchbar);
// find the id's of specific variables.
NavigationUI.setupActionBarWithNavController(this, navController, appBarConfiguration);
NavigationUI.setupWithNavController(navigationView, navController);
toggle.setToolbarNavigationClickListener(v -> {
// Enable the functionality of opening the side drawer, when the burger icon is clicked
toggle.setDrawerIndicatorEnabled(true);
navController.navigate(R.id.main_id);
});
navController.addOnDestinationChangedListener((controller, destination, arguments) -> {
// Hide/show top search bar
if (destination.getId() == R.id.main_id) {
searchbar.setVisibility(View.VISIBLE);
toggle.setHomeAsUpIndicator(R.drawable.nav_back_arrow);
toggle.setDrawerIndicatorEnabled(true); // <<< Add this line of code to enable the burger icon
} else {
searchbar.setVisibility(View.GONE);
}
// Fragments that you want to show the back button
if (destination.getId() == R.id.about_id || destination.getId() == R.id.privacy_policy_id) {
// Disable the functionality of opening the side drawer, when the burger icon is clicked
toggle.setDrawerIndicatorEnabled(false);
}
});
// For scheduling background image change
constraintLayout = findViewById(R.id.layout);
constraintLayout.setBackgroundResource(R.drawable.nyc);
_t = new Timer();
_t.scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
// run on ui thread
runOnUiThread(() -> {
if (count < drawable.length) {
constraintLayout.setBackgroundResource(drawable[count]);
count = (count 1) % drawable.length;
}
});
}
}, 5000, 5000);
Search.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// make click sound when search button is clicked.
player = MediaPlayer.create(HomeActivity.this, R.raw.click);
player.start();
getWeatherData(textfield.getText().toString().trim());
// make use of some fragment's data
Fragment currentFragment = navHostFragment.getChildFragmentManager().getFragments().get(0);
if (currentFragment instanceof MainFragment) {
((MainFragment) currentFragment).getWeatherData(textfield.getText().toString().trim());
}
}
private void getWeatherData(String name) {
ApiInterface apiInterface = ApiClient.getClient().create(ApiInterface.class);
Call<Example> call = apiInterface.getWeatherData(name);
call.enqueue(new Callback<Example>() {
@Override
public void onResponse(@NonNull Call<Example> call, @NonNull Response<Example> response) {
try {
assert response.body() != null;
} catch (Exception e) {
Log.e("TAG", "No City found");
Toast.makeText(HomeActivity.this, "No City found", Toast.LENGTH_SHORT).show();
}
}
@Override
public void onFailure(@NotNull Call<Example> call, @NotNull Throwable t) {
t.printStackTrace();
}
});
}
});
}
@Override
public void onBackPressed() {
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
// Open/close drawer animation
}
}
@Override
protected void onPause() {
super.onPause();
if (viewModel.getMediaPlayer() != null)
viewModel.getMediaPlayer().pause();
}
@Override
protected void onResume() {
super.onResume();
if (viewModel.getMediaPlayer() != null) {
viewModel.getMediaPlayer().start();
viewModel.getMediaPlayer().setLooping(true);
}
}
@Override
public boolean onSupportNavigateUp() {
final NavHostFragment navHostFragment = (NavHostFragment) getSupportFragmentManager().findFragmentById(R.id.fragment);
assert navHostFragment != null;
final NavController navController = navHostFragment.getNavController();
// return NavigationUI.navigateUp(navController,drawer);
return NavigationUI.navigateUp(navController, appBarConfiguration)
|| super.onSupportNavigateUp(); // navigateUp tries to pop the backstack
}
}
MainFragment（Navhost 片段）：
public class MainFragment extends Fragment {
private NavHostFragment navHostFragment;
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
//
BottomNavigationView bottomNavigationView = rootView.findViewById(R.id.bottomNavigationView);
navHostFragment = (NavHostFragment) getChildFragmentManager().findFragmentById(R.id.nav_host_fragment_content_bottom_nav_view);
if (navHostFragment != null) {
NavController navController = navHostFragment.getNavController();
NavigationUI.setupWithNavController(bottomNavigationView, navController);
}
requireActivity().getOnBackPressedDispatcher().addCallback(getViewLifecycleOwner(), new OnBackPressedCallback(true) {
@Override
public void handleOnBackPressed() {
// Exit the app when back is pressed
requireActivity().finish();
}
});
return rootView;
}
public void getWeatherData(String name) {
Fragment currentFragment = navHostFragment.getChildFragmentManager().getFragments().get(0);
if (currentFragment instanceof FirstFragment) {
FirstFragment firstFragment = (FirstFragment) currentFragment;
firstFragment.getWeatherData(name);
} else if (currentFragment instanceof SecondFragment) {
SecondFragment secondFragment = (SecondFragment) currentFragment;
secondFragment.getWeatherData(name);
} else if (currentFragment instanceof ThirdFragment) {
ThirdFragment thirdFragment = (ThirdFragment) currentFragment;
thirdFragment.getWeatherData(name);
}
}
}
其他包括：
*FirstFragment
*SecondFragment
*ThirdFragment with their respective layouts
*Navigation and menu layouts.
我暫時不會發布它們，以減少復雜性，如果需要，請不要猶豫。
uj5u.com熱心網友回復：
因此，當前的導航總結為：
HomeActivity
MainFragment
BottomNavigationView navGraph
FirstFragment
SecondFragment
ThirdFragment
Other fragments...
你需要：
- 安全洗掉
BottomNavigationView - 只保留
FirstFragment和擺脫SecondFragment&ThirdFragment
作為MainFragment唯一的主機BottomNavigationView；然后你可以直接用FirstFragment;替換它 所以導航將是：
HomeActivity
FirstFragment
Other fragments...
為此：
1.在HomeActivity的主navGraph中：
- 替換為
MainFragment（FirstFragment將FirstFragment部分從BottomNavigationViewnavGraph 復制到主 navGraph。 - 將 的 id 重構為
FirstFragment與 關聯的MainFragmentid，因為該 id 用于HomeActivity（或者您可以通過將其重構為 來做另一種方式FirstFragment）
2. 在HomeActivity中，將MainFragment下面的代碼片段替換為 FirstFragment：
if (currentFragment instanceof MainFragment) {
((MainFragment) currentFragment).getWeatherData(textfield.getText().toString().trim());
}
所以，它將是：
if (currentFragment instanceof FirstFragment) {
((FirstFragment) currentFragment).getWeatherData(textfield.getText().toString().trim());
}
這是共享代碼中出現的內容；但你會用 替換每一次出現MainFragment，FirstFragment并進行任何需要的重構。
現在，您可以安全地洗掉MainFragment遺囑的所有后代 BottomNavigationView、第二個和第三個片段；以及它們的資源（布局、選單...），或者如果您打算在未來重復使用它們，請將它們放在一邊。
uj5u.com熱心網友回復：
您是否嘗試將其用于底部導航？
android:visibility="gone"
我以前做同樣的事情。
uj5u.com熱心網友回復：
navController.addOnDestinationChangedListener { _, destination, _ ->
if(destination.id == R.id.first_fragment) {
// your intro fragment will hide your bottomNavigationView
bottomNavigationView.visibility = View.GONE
} else if (destination.id == R.id.second_fragment){
// your second fragment will show your bottomNavigationView
bottomNavigationView.visibility = View.VISIBLE
}
}
您可以根據相關目的地隱藏和顯示。
轉載請註明出處，本文鏈接：https://www.uj5u.com/qukuanlian/513349.html