Java Android - 如何更改导航抽屉中的片段
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时间：2020-08-14 09:39:56 来源:igfitidea点击:
Android - How to change fragments in the Navigation Drawer
提问by ebenstea13
I'm fairly new to Android programming, but have been doing pretty well until now. I've read a lot of answers to this question but can't seem to make mine work. Basically what I have is a MainActivity with a Navigation Drawer. I have two fragments correctly initialized with corresponding fragment layout xmls. Currently I can get my first fragment to show up when the app starts and when I click on each item in the drawer, the titles change; however, the fragment stays the same. Any suggestions? What I believe to be relevant code is below (not shown is the code for the NavigationDrawerFragment.java with the necessary code automatically built by Eclipse). Thanks in advance!
我对 Android 编程还很陌生，但到目前为止一直做得很好。我已经阅读了很多关于这个问题的答案，但似乎无法让我的工作。基本上我拥有的是一个带有导航抽屉的 MainActivity。我有两个片段正确初始化了相应的片段布局 xml。目前我可以在应用程序启动时显示我的第一个片段，当我点击抽屉中的每个项目时，标题会改变；但是，片段保持不变。有什么建议？我认为相关的代码如下（未显示的是 NavigationDrawerFragment.java 的代码，其中包含由 Eclipse 自动构建的必要代码）。提前致谢！
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));
}
}
}
采纳答案by Subhalaxmi
Follow This link!!for more details and use
关注这个链接！！有关更多详细信息和使用
private class DrawerItemClickListener implements
ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
selectItem(position);
}
}
and
和
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);
}
回答by EpicPandaForce
I was working with the Navigation Drawer based on what Eclipse generated as well (yours looks like it was made with it as well), and I've pruned it a bit so that it's not perfectly silly. I also did some black magic at some points, because I was getting silly errors that I've fixed over times (such as being unable to update the action bar title on Back press, or that if you rotate the screen then the element at index 0 is recreated by the activity):
我也在使用基于 Eclipse 生成的导航抽屉（您的看起来也是用它制作的），并且我已经对其进行了一些修剪，以便它不是完全愚蠢的。我还在某些时候做了一些黑魔法，因为我得到了一些我已经修复过的愚蠢错误（例如无法在按下后更新操作栏标题，或者如果你旋转屏幕然后索引处的元素0 由活动重新创建）：
NavigationDrawerActivity:
导航抽屉活动：
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();
}
}
The insidious "GetActionBarTitle":
阴险的“GetActionBarTitle”：
public interface GetActionBarTitle
{
public int getActionBarTitleId();
}
The generated NavigationDrawerFragment (I don't think I've changed this at all):
生成的 NavigationDrawerFragment （我认为我根本没有改变它）：
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();
}
}
An example fragment that is created by this navigation drawer:
此导航抽屉创建的示例片段：
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)
{
}
}
}
I hope that works as you intended. I had to do magic with the BackStackListener and stuff to work properly.
我希望这能如你所愿。我必须对 BackStackListener 和其他东西施展魔法才能正常工作。
回答by CS-
@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();
}
}
and create fragment
并创建片段
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);
}
}
回答by aarcoraci
I know this is quite old, but I would like to share some articles Ive written about the Application Drawer and Fragment navigation. They are up to date with the latest samples (as for 2017 at least). Feel free to take a look at:
我知道这已经很老了，但我想分享一些我写过的关于应用程序抽屉和片段导航的文章。他们是最新的最新样品（至少 2017 年）。随意看看：
