更改片段内的导航抽屉项目

Question

我有一个MainActivity启动导航抽屉。
也有一些碎片。
我需要从Fragments内部更改导航抽屉列表的标题。
我tryed这里面的片段：

navMenuTitles = getActivity().getResources().getStringArray(R.array.nav_drawer_items); 
navMenuTitles[1] = username; 

但至今没有运气。这是我的主要活动：

public class MainActivity extends Activity { 
private DrawerLayout mDrawerLayout; 
private ListView mDrawerList; 
private ActionBarDrawerToggle mDrawerToggle; 

// nav drawer title 
private CharSequence mDrawerTitle; 

// used to store app title 
private CharSequence mTitle; 

// slide menu items 
private String[] navMenuTitles; 
private TypedArray navMenuIcons; 

private ArrayList<NavDrawerItem> navDrawerItems; 
private NavDrawerListAdapter adapter; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 

    mTitle = mDrawerTitle = getTitle(); 

    // load slide menu items 
    navMenuTitles = getResources().getStringArray(R.array.nav_drawer_items); 

    // nav drawer icons from resources 
    navMenuIcons = getResources() 
      .obtainTypedArray(R.array.nav_drawer_icons); 

    mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout); 
    mDrawerList = (ListView) findViewById(R.id.list_slidermenu); 

    navDrawerItems = new ArrayList<NavDrawerItem>(); 

    // adding nav drawer items to array 
    // Home 
    navDrawerItems.add(new NavDrawerItem(navMenuTitles[0], navMenuIcons.getResourceId(0, -1))); 
    // Find People 
    navDrawerItems.add(new NavDrawerItem(navMenuTitles[1], navMenuIcons.getResourceId(1, -1))); 
    // Photos 
    navDrawerItems.add(new NavDrawerItem(navMenuTitles[2], navMenuIcons.getResourceId(2, -1))); 
    // Communities, Will add a counter here 
    navDrawerItems.add(new NavDrawerItem(navMenuTitles[3], navMenuIcons.getResourceId(3, -1), true, "22")); 
    // Pages 
    navDrawerItems.add(new NavDrawerItem(navMenuTitles[4], navMenuIcons.getResourceId(4, -1))); 


    // Recycle the typed array 
    navMenuIcons.recycle(); 

    mDrawerList.setOnItemClickListener(new SlideMenuClickListener()); 

    // setting the nav drawer list adapter 
    adapter = new NavDrawerListAdapter(getApplicationContext(), 
      navDrawerItems); 
    mDrawerList.setAdapter(adapter); 

    // enabling action bar app icon and behaving it as toggle button 
    getActionBar().setDisplayHomeAsUpEnabled(true); 
// getActionBar().setHomeButtonEnabled(true); 

    mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout, 
      R.drawable.ic_drawer, //nav menu toggle icon 
      R.string.app_name, // nav drawer open - description for accessibility 
      R.string.app_name // nav drawer close - description for accessibility 
    ) { 
     public void onDrawerClosed(View view) { 
      getActionBar().setTitle(mTitle); 
      // calling onPrepareOptionsMenu() to show action bar icons 
      invalidateOptionsMenu(); 
     } 

     public void onDrawerOpened(View drawerView) { 
      getActionBar().setTitle(mDrawerTitle); 
      // calling onPrepareOptionsMenu() to hide action bar icons 
      invalidateOptionsMenu(); 
     } 
    }; 
    mDrawerLayout.setDrawerListener(mDrawerToggle); 

    if (savedInstanceState == null) { 
     // on first time display view for first nav item 
     displayView(0); 
    } 
} 

/** 
* Slide menu item click listener 
* */ 
private class SlideMenuClickListener implements 
     ListView.OnItemClickListener { 
    @Override 
    public void onItemClick(AdapterView<?> parent, View view, int position, 
      long id) { 
     // display view for selected nav drawer item 
     displayView(position); 
    } 
} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    getMenuInflater().inflate(R.menu.main, menu); 
    return true; 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    // toggle nav drawer on selecting action bar app icon/title 
    if (mDrawerToggle.onOptionsItemSelected(item)) { 
     return true; 
    } 
    // Handle action bar actions click 
    switch (item.getItemId()) { 
    case R.id.action_settings: 
     return true; 
    default: 
     return super.onOptionsItemSelected(item); 
    } 
} 

/* * 
* Called when invalidateOptionsMenu() is triggered 
*/ 
@Override 
public boolean onPrepareOptionsMenu(Menu menu) { 
    // if nav drawer is opened, hide the action items 
    boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList); 
    menu.findItem(R.id.action_settings).setVisible(!drawerOpen); 
    return super.onPrepareOptionsMenu(menu); 
} 

/** 
* Diplaying fragment view for selected nav drawer list item 
* */ 
private void displayView(int position) { 
    // update the main content by replacing fragments 
    Fragment fragment = null; 
    switch (position) { 
    case 0: 
     fragment = new HomeFragment(); 
     break; 
    case 1: 
     fragment = new LoginFragment(); 
     break; 
    case 2: 
     fragment = new PhotosFragment(); 
     break; 
    case 3: 
     fragment = new CommunityFragment(); 
     break; 
    case 4: 
     fragment = new PagesFragment(); 
     break; 
    case 5: 
     fragment = new WhatsHotFragment(); 
     break; 

    default: 
     break; 
    } 

    if (fragment != null) { 
     FragmentManager fragmentManager = getFragmentManager(); 
     fragmentManager.beginTransaction() 
       .replace(R.id.frame_container, fragment).commit(); 

     // update selected item and title, then close the drawer 
     mDrawerList.setItemChecked(position, true); 
     mDrawerList.setSelection(position); 
     setTitle(navMenuTitles[position]); 
     mDrawerLayout.closeDrawer(mDrawerList); 
    } else { 
     // error in creating fragment 
     Log.e("MainActivity", "Error in creating fragment"); 
    } 
} 

@Override 
public void setTitle(CharSequence title) { 
    mTitle = title; 
    getActionBar().setTitle(mTitle); 
} 

/** 
* When using the ActionBarDrawerToggle, you must call it during 
* onPostCreate() and onConfigurationChanged()... 
*/ 

@Override 
protected void onPostCreate(Bundle savedInstanceState) { 
    super.onPostCreate(savedInstanceState); 
    // Sync the toggle state after onRestoreInstanceState has occurred. 
    mDrawerToggle.syncState(); 
} 

@Override 
public void onConfigurationChanged(Configuration newConfig) { 
    super.onConfigurationChanged(newConfig); 
    // Pass any configuration change to the drawer toggls 
    mDrawerToggle.onConfigurationChanged(newConfig); 
} 

在Main Activity类中使用相同的方法工作，但不在Fragment中。我不知道如何更新字符串并通知这个变化的抽屉！

Answer 1

public interface OnContactSelected { 
     void OnContactSelected (String selectedContactID); 
} 

在您的片段

@Override 
public void onAttach(Activity activity) { 
    super.onAttach(activity); 

    mOnContactSelected = (OnContactSelected) getActivity(); 

} 

我想，你希望当您单击列表视图项

@Override 
    public void onListItemClick(ListView listView, View view, int position, 
      long loc) { 
     super.onListItemClick(listView, view, position, loc); 

      mOnContactSelected.OnContactSelected ("clicked"); 

    } 

改变抽屉式导航栏的标题现在实行“OnContactSelected”在你的活动。现在您将在活动中接到回电。然后您可以在那里设置标题

@Override 
    public void OnContactSelected (String selectedContactID) 
{ 
// Change the navigation title here 
     }