Question

我收到错误，当我单击LoginFragment时。当我删除loginFragment时。它工作正常。如何更改添加更多片段的长度。我无法添加新片段。

MainActivity.java

public class MainActivity extends AppCompatActivity {
private static final String TAG_HOME = "home";
private static final String TAG_PHOTOS = "photos";
private static final String TAG_MOVIES = "movies";
private static final String TAG_NOTIFICATIONS = "notifications";
private static final String TAG_SETTINGS = "settings";
private static final String TAG_LOGIN = "login";


public static int navItemIndex = 0;
public static String CURRENT_TAG = TAG_HOME;
private NavigationView navigationView;
private DrawerLayout drawer;


private Toolbar toolbar;
private String[] activityTitles;

// flag to load home fragment when user presses back key
   private boolean shouldLoadHomeFragOnBackPress = true;
  private Handler mHandler;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    mHandler = new Handler();

    drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    navigationView = (NavigationView) findViewById(R.id.nav_view);


    // Navigation view header


    // load toolbar titles from string resources
    activityTitles = getResources().getStringArray(R.array.nav_item_activity_titles);


    // load nav menu header data


    // initializing navigation menu
    setUpNavigationView();

    if (savedInstanceState == null) {
        navItemIndex = 0;
        CURRENT_TAG = TAG_HOME;
        loadHomeFragment();
    }
}


private void loadHomeFragment() {
    // selecting appropriate nav menu item
    selectNavMenu();

    // set toolbar title
    setToolbarTitle();

    // if user select the current navigation menu again, don't do anything
    // just close the navigation drawer
    if (getSupportFragmentManager().findFragmentByTag(CURRENT_TAG) != null) {
        drawer.closeDrawers();

        // show or hide the fab button

        return;
    }


    Runnable mPendingRunnable = new Runnable() {
        @Override
        public void run() {
            // update the main content by replacing fragments
            Fragment fragment = getHomeFragment();
            FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
            fragmentTransaction.setCustomAnimations(android.R.anim.fade_in,
                    android.R.anim.fade_out);
            fragmentTransaction.replace(R.id.frame, fragment, CURRENT_TAG);
            fragmentTransaction.commitAllowingStateLoss();
        }
    };

    // If mPendingRunnable is not null, then add to the message queue
    if (mPendingRunnable != null) {
        mHandler.post(mPendingRunnable);
    }
    //Closing drawer on item click
    drawer.closeDrawers();

    // refresh toolbar menu
    invalidateOptionsMenu();
}

private Fragment getHomeFragment() {
    switch (navItemIndex) {
        case 0:
            // home
            HomeFragment homeFragment = new HomeFragment();
            return homeFragment;
        case 1:
            // photos
            PhotosFragment photosFragment = new PhotosFragment();
            return photosFragment;
        case 2:
            // movies fragment
            MoviesFragment moviesFragment = new MoviesFragment();
            return moviesFragment;
        case 3:
            // notifications fragment
            NotificationsFragment notificationsFragment = new NotificationsFragment();
            return notificationsFragment;

        case 4:
            // settings fragment
            SettingsFragment settingsFragment = new SettingsFragment();
            return settingsFragment;
        case 5:
            // ic_login_black_24dp fragment
            LoginFragment loginFragment = new LoginFragment();
            return loginFragment;

        default:
            return new HomeFragment();
    }
}

private void setToolbarTitle() {
    getSupportActionBar().setTitle(activityTitles[navItemIndex]);
}

private void selectNavMenu() {
    navigationView.getMenu().getItem(navItemIndex).setChecked(true);
}

private void setUpNavigationView() {
    //Setting Navigation View Item Selected Listener to handle the item click of the navigation menu
    navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {

        // This method will trigger on item Click of navigation menu
        @Override
        public boolean onNavigationItemSelected(MenuItem menuItem) {

            //Check to see which item was being clicked and perform appropriate action
            switch (menuItem.getItemId()) {
                //Replacing the main content with ContentFragment Which is our Inbox View;
                case R.id.home:
                    navItemIndex = 0;
                    CURRENT_TAG = TAG_HOME;
                    break;
                case R.id.nav_photos:
                    navItemIndex = 1;
                    CURRENT_TAG = TAG_PHOTOS;
                    break;
                case R.id.nav_movies:
                    navItemIndex = 2;
                    CURRENT_TAG = TAG_MOVIES;
                    break;
                case R.id.nav_notifications:
                    navItemIndex = 3;
                    CURRENT_TAG = TAG_NOTIFICATIONS;
                    break;
                case R.id.nav_settings:
                    navItemIndex = 4;
                    CURRENT_TAG = TAG_SETTINGS;
                    break;
                case R.id.nav_login:
                    navItemIndex = 5;
                    CURRENT_TAG = TAG_LOGIN;
                    break;


                default:
                    navItemIndex = 0;
            }

            //Checking if the item is in checked state or not, if not make it in checked state
            if (menuItem.isChecked()) {
                menuItem.setChecked(false);
            } else {
                menuItem.setChecked(true);
            }
            menuItem.setChecked(true);

            loadHomeFragment();

            return true;
        }
    });


    ActionBarDrawerToggle actionBarDrawerToggle = new ActionBarDrawerToggle(this, drawer, toolbar, R.string.openDrawer, R.string.closeDrawer) {

        @Override
        public void onDrawerClosed(View drawerView) {
            // Code here will be triggered once the drawer closes as we dont want anything to happen so we leave this blank
            super.onDrawerClosed(drawerView);
        }

        @Override
        public void onDrawerOpened(View drawerView) {
            // Code here will be triggered once the drawer open as we dont want anything to happen so we leave this blank
            super.onDrawerOpened(drawerView);
        }
    };

    //Setting the actionbarToggle to drawer layout
    drawer.setDrawerListener(actionBarDrawerToggle);

    //calling sync state is necessary or else your hamburger icon wont show up
    actionBarDrawerToggle.syncState();
}

@Override
public void onBackPressed() {
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawers();
        return;
    }

    // This code loads home fragment when back key is pressed
    // when user is in other fragment than home
    if (shouldLoadHomeFragOnBackPress) {
        // checking if user is on other navigation menu
        // rather than home
        if (navItemIndex != 0) {
            navItemIndex = 0;
            CURRENT_TAG = TAG_HOME;
            loadHomeFragment();
            return;
        }
    }

    super.onBackPressed();
}
}

activity_main_drawer.xml

<group android:checkableBehavior="single">
    <item
        android:id="@+id/nav_home"
        android:icon="@drawable/ic_home_black_24dp"
        android:title="@string/nav_home" />
    <item
        android:id="@+id/nav_photos"
        android:icon="@drawable/ic_photo_library_black_24dp"
        android:title="@string/nav_photos" />
    <item
        android:id="@+id/nav_movies"
        android:icon="@drawable/ic_local_movies_black_24dp"
        android:title="@string/nav_movies" />

    <item
        android:id="@+id/nav_notifications"
        android:icon="@drawable/ic_notifications_black_24dp"
        android:title="@string/nav_notifications" />

    <item
        android:id="@+id/nav_settings"
        android:icon="@drawable/ic_settings_black_24dp"
        android:title="@string/nav_settings" />
    <item
        android:id="@+id/nav_login"
        android:icon="@drawable/ic_login_black_24dp"
        android:title="login" />

</group>

activity_main.xml中

<android.support.v4.widget.DrawerLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:openDrawer="start">

<include
    layout="@layout/app_bar_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

<android.support.design.widget.NavigationView
    android:id="@+id/nav_view"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:fitsSystemWindows="true"
    app:headerLayout="@layout/nav_header_main"
    app:menu="@menu/activity_main_drawer" />

  </android.support.v4.widget.DrawerLayout>

app_bar_main.xml

<android.support.design.widget.CoordinatorLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="info.androidhive.navigationdrawer.activity.MainActivity">

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:popupTheme="@style/AppTheme.PopupOverlay" />

</android.support.design.widget.AppBarLayout>

<FrameLayout
    android:id="@+id/frame"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">
</FrameLayout>
</android.support.design.widget.CoordinatorLayout>

nav_header_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/view_container"
android:layout_width="match_parent"
android:layout_height="@dimen/nav_header_height"
android:gravity="bottom"
android:orientation="vertical"
android:theme="@style/ThemeOverlay.AppCompat.Dark">

<ImageView
    android:id="@+id/img_header_bg"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:scaleType="fitXY"
    android:src="@mipmap/ic_launcher" />

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerVertical="true"
    android:orientation="vertical"
    android:padding="@dimen/activity_horizontal_margin">

    <ImageView
        android:id="@+id/img_profile"
        android:layout_width="@dimen/profile_width"
        android:layout_height="@dimen/profile_height"
        android:paddingTop="@dimen/nav_header_vertical_spacing"
        app:srcCompat="@android:drawable/sym_def_app_icon" />

    <TextView
        android:id="@+id/namea"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:paddingTop="@dimen/nav_header_vertical_spacing"
        android:textAppearance="@style/TextAppearance.AppCompat.Body1" />

    <TextView
        android:id="@+id/website"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

Answer 1

java.lang.ArrayIndexOutOfBoundsException：length = 5;索引= 5？

当您致电：

时，看起来会发生异常

 getSupportActionBar().setTitle(activityTitles[navItemIndex]);

当navItemIndex只有5个项目时，

activityTitles的范围为0到5（a.e。长度为6）

解决方案：

为activityTitles

设置6项

java.lang.ArrayIndexOutOfBoundsException：length = 5;索引= 5？我想在导航栏

1 个答案: