如何从导航抽屉选项卡导航回 activity？
How to navigate back to activity from navigation drawer tabs?
我有一个带 3 个主要选项卡的导航抽屉 https://i.stack.imgur.com/SIjdx.jpg。在每个选项卡中，即设置和其余选项卡中，我实现了一个顶部后退按钮，returns 到
单击主页 activity。我也尝试处理底部后退按钮，但现在的问题是，如果我单击底部后退按钮（phone 手势导航）https://i.stack.imgur.com/RYW16.jpg，它只会退出应用程序而不是 return如期回家Activity。
我想让它 return 回到主页 activity 这样我就可以使用顶部和底部的后退按钮浏览选项卡，我该怎么做请更正此问题？
我在本站查过类似问题，还没有找到解决办法。
这是我的设置代码（我对其他选项卡也使用相同的代码）：
public class Settings extends Fragment {
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.settings, container, false);
requireActivity().getOnBackPressedDispatcher().addCallback(getViewLifecycleOwner(), new OnBackPressedCallback(true) {
@Override
public void handleOnBackPressed() {
requireActivity().finish();
}
});
return view;
}
}
编辑:
首页Activity:
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.dubai, R.drawable.norway, R.drawable.eiffel_tower, R.drawable.hong_kong, R.drawable.statue_of_liberty,
R.drawable.beijing, R.drawable.chicago, R.drawable.colombia, R.drawable.vienna, R.drawable.tokyo};
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.ic_baseline_arrow_back_24);
} else {
searchbar.setVisibility(View.GONE);
}
// Fragments that you want to show the back button
if (destination.getId() == R.id.settings_id || destination.getId() == R.id.ads_upgrade_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.dubai);
_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
}
}
使用 onBackPressed() 函数覆盖后退按钮的操作。这是一些示例代码：
override fun onBackPressed() {
val intent = Intent(requireActivity(),HomeActivity::class.java)
requireActivity().startActivity(intent)
}
在 onBackPressed() 函数中写入您想要的操作。
为了 return 到 activity 而不是在单击底部后退按钮时存在该应用程序：
从所有相关片段（如 SettingFragment）中删除以下回调：
requireActivity().getOnBackPressedDispatcher().addCallback(getViewLifecycleOwner(), new OnBackPressedCallback(true) {
@Override
public void handleOnBackPressed() {
requireActivity().finish();
}
});
导航组件会处理返回堆栈，所以不用担心。当你回到家时会出现一个小问题activity;你会看到向上按钮而不是汉堡图标；要解决此问题，您需要在返回 addOnDestinationChangedListener
时添加 toggle.setDrawerIndicatorEnabled(true)
所以，在 HomeActivity:
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.ic_baseline_arrow_back_24);
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.settings_id || destination.getId() == R.id.ads_upgrade_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);
}
});
声音应该会继续播放，因为您没有创建全新的 activity。
我有一个带 3 个主要选项卡的导航抽屉 https://i.stack.imgur.com/SIjdx.jpg。在每个选项卡中，即设置和其余选项卡中，我实现了一个顶部后退按钮，returns 到 单击主页 activity。我也尝试处理底部后退按钮，但现在的问题是，如果我单击底部后退按钮（phone 手势导航）https://i.stack.imgur.com/RYW16.jpg，它只会退出应用程序而不是 return如期回家Activity。
我想让它 return 回到主页 activity 这样我就可以使用顶部和底部的后退按钮浏览选项卡，我该怎么做请更正此问题？
我在本站查过类似问题，还没有找到解决办法。
这是我的设置代码（我对其他选项卡也使用相同的代码）：
public class Settings extends Fragment {
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.settings, container, false);
requireActivity().getOnBackPressedDispatcher().addCallback(getViewLifecycleOwner(), new OnBackPressedCallback(true) {
@Override
public void handleOnBackPressed() {
requireActivity().finish();
}
});
return view;
}
}
编辑:
首页Activity:
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.dubai, R.drawable.norway, R.drawable.eiffel_tower, R.drawable.hong_kong, R.drawable.statue_of_liberty,
R.drawable.beijing, R.drawable.chicago, R.drawable.colombia, R.drawable.vienna, R.drawable.tokyo};
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.ic_baseline_arrow_back_24);
} else {
searchbar.setVisibility(View.GONE);
}
// Fragments that you want to show the back button
if (destination.getId() == R.id.settings_id || destination.getId() == R.id.ads_upgrade_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.dubai);
_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
}
}
使用 onBackPressed() 函数覆盖后退按钮的操作。这是一些示例代码：
override fun onBackPressed() {
val intent = Intent(requireActivity(),HomeActivity::class.java)
requireActivity().startActivity(intent)
}
在 onBackPressed() 函数中写入您想要的操作。
为了 return 到 activity 而不是在单击底部后退按钮时存在该应用程序：
从所有相关片段（如 SettingFragment）中删除以下回调：
requireActivity().getOnBackPressedDispatcher().addCallback(getViewLifecycleOwner(), new OnBackPressedCallback(true) {
@Override
public void handleOnBackPressed() {
requireActivity().finish();
}
});
导航组件会处理返回堆栈，所以不用担心。当你回到家时会出现一个小问题activity;你会看到向上按钮而不是汉堡图标；要解决此问题，您需要在返回 addOnDestinationChangedListener
toggle.setDrawerIndicatorEnabled(true)
所以，在 HomeActivity:
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.ic_baseline_arrow_back_24);
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.settings_id || destination.getId() == R.id.ads_upgrade_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);
}
});
声音应该会继续播放，因为您没有创建全新的 activity。