Android-ナビゲーションドロワーでフラグメントを変更する方法
私はAndroidプログラミングにかなり慣れていますが、これまでかなり順調でした。この質問に対する多くの答えを読みましたが、私の仕事がうまくいかないようです。ナビゲーションドロワーを持つMainActivityがあり、対応するフラグメントレイアウトxmlで正しく初期化された2つのフラグメントがあります。現在、アプリの起動時とドロワー内の各アイテムをクリックすると、タイトルが変わる最初のフラグメントを表示できます;ただし、フラグメントは同じままです。何か提案がありますか？関連するコードと思われるものを以下に示します（必要なコードがEclipseによって自動的に構築されたNavigationDrawerFragment.Javaのコードは表示されません）。
public class MainActivity extends Activity
implements NavigationDrawerFragment.NavigationDrawerCallbacks {
/**
* Fragment managing the behaviors, interactions and presentation of the navigation drawer.
*/
private NavigationDrawerFragment mNavigationDrawerFragment;
/**
* Used to store the last screen title. For use in {@link #restoreActionBar()}.
*/
private CharSequence mTitle;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mNavigationDrawerFragment = (NavigationDrawerFragment)
getFragmentManager().findFragmentById(R.id.navigation_drawer);
mTitle = getTitle();
// Set up the drawer.
mNavigationDrawerFragment.setUp(
R.id.navigation_drawer,
(DrawerLayout) findViewById(R.id.drawer_layout));
}
@Override
public void onNavigationDrawerItemSelected(int position) {
// update the main content by replacing fragments
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.content_frame, PlaceholderFragment.newInstance(position + 1))
.commit();
}
public void onSectionAttached(int number) {
switch (number) {
case 1:
mTitle = getString(R.string.title_home);
break;
case 2:
mTitle = getString(R.string.title_infodirect);
break;
case 3:
mTitle = getString(R.string.title_trailmap);
break;
case 4:
mTitle = getString(R.string.title_poi);
break;
case 5:
mTitle = getString(R.string.title_photomap);
break;
case 6:
mTitle = getString(R.string.title_report);
break;
case 7:
mTitle = getString(R.string.title_rulesreg);
}
}
public void restoreActionBar() {
ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
actionBar.setDisplayShowTitleEnabled(true);
actionBar.setTitle(mTitle);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
if (!mNavigationDrawerFragment.isDrawerOpen()) {
// Only show items in the action bar relevant to this screen
// if the drawer is not showing. Otherwise, let the drawer
// decide what to show in the action bar.
getMenuInflater().inflate(R.menu.overview, menu);
restoreActionBar();
return true;
}
return super.onCreateOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_NUMBER = "section_number";
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_home, container, false);
return rootView;
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
((MainActivity) activity).onSectionAttached(
getArguments().getInt(ARG_SECTION_NUMBER));
}
}
public static class InfoDirectFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_NUMBER = "section_number";
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static InfoDirectFragment newInstance(int sectionNumber) {
InfoDirectFragment fragment = new InfoDirectFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
public InfoDirectFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_infodirect, container, false);
return rootView;
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
((MainActivity) activity).onSectionAttached(
getArguments().getInt(ARG_SECTION_NUMBER));
}
}
}
詳細はこちら link !! をご覧ください
private class DrawerItemClickListener implements
ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
selectItem(position);
}
}
そして
private void selectItem(int position) {
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction ft = fragmentManager.beginTransaction();
switch (position) {
case 0:
ft.replace(R.id.content_frame, new Fragment1, Constants.TAG_FRAGMENT).commit();
break;
case 1:
ft.replace(R.id.content_frame, new Fragment2, Constants.TAG_FRAGMENT);
ft.commit();
break;
}
mDrawerList.setItemChecked(position, true);
setTitle(title[position]);
// Close drawer
mDrawerLayout.closeDrawer(mDrawerList);
}
@Override
public void onNavigationDrawerItemSelected(int position) {
// update the main content by replacing fragments
FragmentManager fragmentManager = getSupportFragmentManager();
if (position == 0) {
fragmentManager.beginTransaction()
.replace(R.id.container, FirstFragment.newInstance())
.commit();
} else if (position == 1) {
fragmentManager.beginTransaction()
.replace(R.id.container, SecondFragment.newInstance())
.commit();
} else if (position == 2) {
fragmentManager.beginTransaction()
.replace(R.id.container, ThridFragment.newInstance())
.commit();
}
}
フラグメントを作成します
public class FirstFragment extends Fragment {
public static FirstFragment newInstance() {
FirstFragment fragment = new FirstFragment();
return fragment;
}
public FirstFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_first, container, false);
return rootView;
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
((MainActivity) activity).onSectionAttached(1);
}
}
私もEclipseが生成したものに基づいてNavigation Drawerを使用していましたが（あなたのものも同様に作成されているようです）、私はそれを少し刈り込みました。また、ある時点で黒魔術を行いました。これは、時間をかけて修正した愚かなエラーが発生したためです（バックプレスでアクションバーのタイトルを更新できない、または画面を回転させてインデックスの要素を回転させるなど） 0はアクティビティによって再作成されます）：
NavigationDrawerActivity：
public class NavigationDrawerActivity extends ActionBarActivity implements
NavigationDrawerFragment.NavigationDrawerCallbacks
{
/**
* Fragment managing the behaviors, interactions and presentation of the navigation drawer.
*/
private NavigationDrawerFragment mNavigationDrawerFragment;
/**
* Used to store the last screen title. For use in {@link #restoreActionBar()}.
*/
private CharSequence mTitle;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mNavigationDrawerFragment = (NavigationDrawerFragment) getSupportFragmentManager()
.findFragmentById(R.id.navigation_drawer);
mTitle = getString(R.string.drawer_0);
// Set up the drawer.
mNavigationDrawerFragment.setUp(R.id.navigation_drawer,
(DrawerLayout) findViewById(R.id.drawer_layout));
getSupportFragmentManager().addOnBackStackChangedListener(new OnBackStackChangedListener()
{
public void onBackStackChanged()
{
int backCount = getSupportFragmentManager().getBackStackEntryCount();
if (backCount == 0)
{
finish();
}
else
{
Fragment fragment = getSupportFragmentManager().findFragmentById(R.id.container);
mTitle = getString(((GetActionBarTitle) fragment).getActionBarTitleId());
restoreActionBar();
}
}
});
if (savedInstanceState != null)
{
this.onBackPressed();
}
}
public void restoreActionBar()
{
ActionBar actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
actionBar.setDisplayShowTitleEnabled(true);
actionBar.setTitle(mTitle);
}
@Override
public boolean onCreateOptionsMenu(Menu menu)
{
if (!mNavigationDrawerFragment.isDrawerOpen())
{
// Only show items in the action bar relevant to this screen
// if the drawer is not showing. Otherwise, let the drawer
// decide what to show in the action bar.
getMenuInflater().inflate(R.menu.main, menu);
restoreActionBar();
return true;
}
return super.onCreateOptionsMenu(menu);
}
@Override
public void onNavigationDrawerItemSelected(int position)
{
// update the main content by replacing fragments
FragmentManager fragmentManager = getSupportFragmentManager();
boolean addToBackStack = true;
Fragment fragment = null;
switch (position)
{
case 0:
fragment = new Fragment0();
break;
case 1:
fragment = new Fragment1();
break;
case 2:
fragment = new Fragment2();
break;
case 3:
fragment = new Fragment3();
break;
case 4:
fragment = new Fragment4();
break;
case 5:
logout();
default:
Log.w(this.getClass().getSimpleName(),
"Reached Default in onNavigationDrawerItemSelected!");
break;
}
if (fragment != null)
{
FragmentTransaction ft = fragmentManager.beginTransaction();
ft.replace(R.id.container, fragment);
if (addToBackStack == true)
{
ft.addToBackStack(null);
}
ft.commit();
mTitle = getString(((GetActionBarTitle) fragment).getActionBarTitleId());
restoreActionBar();
}
}
public void logout()
{
this.finish();
}
}
陰湿な「GetActionBarTitle」：
public interface GetActionBarTitle
{
public int getActionBarTitleId();
}
生成されたNavigationDrawerFragment（これをまったく変更したとは思わない）：
public class NavigationDrawerFragment extends Fragment
{
/**
* Remember the position of the selected item.
*/
private static final String STATE_SELECTED_POSITION = "selected_navigation_drawer_position";
/**
* Per the design guidelines, you should show the drawer on launch until the user manually expands
* it. This shared
* preference tracks this.
*/
private static final String PREF_USER_LEARNED_DRAWER = "navigation_drawer_learned";
/**
* A pointer to the current callbacks instance (the Activity).
*/
private NavigationDrawerCallbacks mCallbacks;
/**
* Helper component that ties the action bar to the navigation drawer.
*/
private ActionBarDrawerToggle mDrawerToggle;
private DrawerLayout mDrawerLayout;
private ListView mDrawerListView;
private View mFragmentContainerView;
private int mCurrentSelectedPosition = 0;
private boolean mFromSavedInstanceState;
private boolean mUserLearnedDrawer;
public NavigationDrawerFragment()
{
}
/**
* Callbacks interface that all activities using this fragment must implement.
*/
public static interface NavigationDrawerCallbacks
{
/**
* Called when an item in the navigation drawer is selected.
*/
void onNavigationDrawerItemSelected(int position);
}
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
// Read in the flag indicating whether or not the user has demonstrated awareness of the
// drawer. See PREF_USER_LEARNED_DRAWER for details.
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(getActivity());
mUserLearnedDrawer = sp.getBoolean(PREF_USER_LEARNED_DRAWER, false);
if (savedInstanceState != null)
{
mCurrentSelectedPosition = savedInstanceState.getInt(STATE_SELECTED_POSITION);
mFromSavedInstanceState = true;
}
// Select either the default item (0) or the last selected item.
selectItem(mCurrentSelectedPosition);
}
@Override
public void onActivityCreated(Bundle savedInstanceState)
{
super.onActivityCreated(savedInstanceState);
// Indicate that this fragment would like to influence the set of actions in the action bar.
setHasOptionsMenu(true);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
mDrawerListView = (ListView) inflater.inflate(R.layout.fragment_navigation_drawer, container,
false);
mDrawerListView.setOnItemClickListener(new AdapterView.OnItemClickListener()
{
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
selectItem(position);
}
});
String[] drawerTitles = new String[] { getString(R.string.drawer_0),
getString(R.string.drawer_1),
getString(R.string.drawer_2), getString(R.string.drawer_3),
getString(R.string.drawer_4), getString(R.string.drawer_5) };
mDrawerListView.setAdapter(new ArrayAdapter<String>(getActionBar().getThemedContext(),
Android.R.layout.simple_list_item_1, Android.R.id.text1, drawerTitles));
mDrawerListView.setItemChecked(mCurrentSelectedPosition, true);
return mDrawerListView;
}
public boolean isDrawerOpen()
{
return mDrawerLayout != null && mDrawerLayout.isDrawerOpen(mFragmentContainerView);
}
/**
* Users of this fragment must call this method to set up the navigation drawer interactions.
*
* @param fragmentId
* The Android:id of this fragment in its activity's layout.
* @param drawerLayout
* The DrawerLayout containing this fragment's UI.
*/
public void setUp(int fragmentId, DrawerLayout drawerLayout)
{
mFragmentContainerView = getActivity().findViewById(fragmentId);
mDrawerLayout = drawerLayout;
// set a custom shadow that overlays the main content when the drawer opens
mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
// set up the drawer's list view with items and click listener
ActionBar actionBar = getActionBar();
actionBar.setDisplayHomeAsUpEnabled(true);
actionBar.setHomeButtonEnabled(true);
// ActionBarDrawerToggle ties together the the proper interactions
// between the navigation drawer and the action bar app icon.
mDrawerToggle = new ActionBarDrawerToggle(getActivity(), /* Host Activity */
mDrawerLayout, /* DrawerLayout object */
R.drawable.ic_drawer, /* nav drawer image to replace 'Up' caret */
R.string.navigation_drawer_open, /* "open drawer" description for accessibility */
R.string.navigation_drawer_close /* "close drawer" description for accessibility */
)
{
@Override
public void onDrawerClosed(View drawerView)
{
super.onDrawerClosed(drawerView);
if (!isAdded())
{
return;
}
getActivity().supportInvalidateOptionsMenu(); // calls onPrepareOptionsMenu()
}
@Override
public void onDrawerOpened(View drawerView)
{
super.onDrawerOpened(drawerView);
if (!isAdded())
{
return;
}
if (!mUserLearnedDrawer)
{
// The user manually opened the drawer; store this flag to prevent auto-showing
// the navigation drawer automatically in the future.
mUserLearnedDrawer = true;
SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(getActivity());
sp.edit().putBoolean(PREF_USER_LEARNED_DRAWER, true).apply();
}
getActivity().supportInvalidateOptionsMenu(); // calls onPrepareOptionsMenu()
}
};
// If the user hasn't 'learned' about the drawer, open it to introduce them to the drawer,
// per the navigation drawer design guidelines.
if (!mUserLearnedDrawer && !mFromSavedInstanceState)
{
mDrawerLayout.openDrawer(mFragmentContainerView);
}
// Defer code dependent on restoration of previous instance state.
mDrawerLayout.post(new Runnable()
{
@Override
public void run()
{
mDrawerToggle.syncState();
}
});
mDrawerLayout.setDrawerListener(mDrawerToggle);
}
private void selectItem(int position)
{
mCurrentSelectedPosition = position;
if (mDrawerListView != null)
{
mDrawerListView.setItemChecked(position, true);
}
if (mDrawerLayout != null)
{
mDrawerLayout.closeDrawer(mFragmentContainerView);
}
if (mCallbacks != null)
{
mCallbacks.onNavigationDrawerItemSelected(position);
}
}
@Override
public void onAttach(Activity activity)
{
super.onAttach(activity);
try
{
mCallbacks = (NavigationDrawerCallbacks) activity;
}
catch (ClassCastException e)
{
throw new ClassCastException("Activity must implement NavigationDrawerCallbacks.");
}
}
@Override
public void onDetach()
{
super.onDetach();
mCallbacks = null;
}
@Override
public void onSaveInstanceState(Bundle outState)
{
super.onSaveInstanceState(outState);
outState.putInt(STATE_SELECTED_POSITION, mCurrentSelectedPosition);
}
@Override
public void onConfigurationChanged(Configuration newConfig)
{
super.onConfigurationChanged(newConfig);
// Forward the new configuration the drawer toggle component.
mDrawerToggle.onConfigurationChanged(newConfig);
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater)
{
// If the drawer is open, show the global app actions in the action bar. See also
// showGlobalContextActionBar, which controls the top-left area of the action bar.
if (mDrawerLayout != null && isDrawerOpen())
{
inflater.inflate(R.menu.global, menu);
showGlobalContextActionBar();
}
super.onCreateOptionsMenu(menu, inflater);
}
@Override
public boolean onOptionsItemSelected(MenuItem item)
{
if (mDrawerToggle.onOptionsItemSelected(item))
{
return true;
}
/*
* if (item.getItemId() == R.id.action_example)
* {
* Toast.makeText(getActivity(), "Example action.", Toast.LENGTH_SHORT).show();
* return true;
* }
*/
return super.onOptionsItemSelected(item);
}
/**
* Per the navigation drawer design guidelines, updates the action bar to show the global app
* 'context', rather than
* just what's in the current screen.
*/
private void showGlobalContextActionBar()
{
ActionBar actionBar = getActionBar();
actionBar.setDisplayShowTitleEnabled(true);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
actionBar.setTitle(R.string.app_name);
}
private ActionBar getActionBar()
{
return ((ActionBarActivity) getActivity()).getSupportActionBar();
}
}
このナビゲーションドロワーによって作成されるフラグメントの例：
public class MyFragment extends Fragment implements GetActionBarTitle, OnClickListener
{
private int titleId;
private Button btn0;
private Button btn1;
private Button btn2;
public MyFragment()
{
super();
titleId = R.string.drawer_myfragment_title;
}
@Override
public int getActionBarTitleId()
{
return titleId;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View rootView = inflater.inflate(R.layout.fragment_myfragment, container, false);
return rootView;
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState)
{
super.onViewCreated(view, savedInstanceState);
btn0 = (Button) view.findViewById(R.id.btn0);
btn1 = (Button) view.findViewById(R.id.btn1);
btn2 = (Button) view.findViewById(R.id.btn2);
btn0.setOnClickListener(this);
btn1.setOnClickListener(this);
btn2.setOnClickListener(this);
}
@Override
public void onClick(View v)
{
if (btn0 == v)
{
}
else if (btn1 == v)
{
}
else if (btn2 == v)
{
}
}
}
意図したとおりに機能することを願っています。 BackStackListenerなどを適切に動作させるために魔法をかける必要がありました。
これはかなり古いことは知っていますが、Application DrawerとFragmentナビゲーションについて書いた記事をいくつか共有したいと思います。それらは最新のサンプルで最新です（少なくとも2017年に関して）。以下をご覧ください。