Пользовательский навигационный ящик не показывает фрагмент
Я пытаюсь создать список избранного в моем приложении, для этой цели я использовал этот учебник:
http://androidopentutorials.com/android-sharedpreferences-tutorial-and-example/
но чтобы получить избранное, я использовал NavigationDrawer вместо ActionBar.
Проблема заключается в том, что ничего не происходит, когда я выбираю "Избранное" или "Дом в ящике".
Logcat показывает только одну ошибку, которая не связана с моей проблемой.
Где я ошибся?
Ошибка:
06-30 17:41:48.530 6971-6971/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.boom.kayakapp, PID: 6971
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Object android.widget.ImageView.getTag()' on a null object reference
at com.boom.kayakapp.activities.MainActivity$2.onItemLongClick(MainActivity.java:148)
at android.widget.AbsListView.showContextMenuForChild(AbsListView.java:3162)
at android.view.ViewGroup.showContextMenuForChild(ViewGroup.java:693)
at android.view.ViewGroup.showContextMenuForChild(ViewGroup.java:693)
at android.view.View.showContextMenu(View.java:4853)
at android.view.View.performLongClick(View.java:4822)
at android.widget.TextView.performLongClick(TextView.java:8684)
at android.view.View$CheckForLongPress.run(View.java:19840)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5257)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
--------- beginning of system
06-30 17:41:48.572 933-933/? E/EGL_emulation﹕ tid 933: eglCreateSyncKHR(1237): error 0x3004 (EGL_BAD_ATTRIBUTE)
06-30 17:41:50.823 1232-1274/system_process E/InputDispatcher﹕ channel '10153f49 com.boom.kayakapp/com.boom.kayakapp.activities.MainActivity (server)' ~ Channel is unrecoverably broken and will be disposed!
06-30 17:42:02.006 7546-7546/? E/memtrack﹕ Couldn't load memtrack module (No such file or directory)
06-30 17:42:02.006 7546-7546/? E/android.os.Debug﹕ failed to load memtrack module: -2
06-30 17:42:02.041 7546-7555/? E/art﹕ Thread attaching while runtime is shutting down: Binder_1
06-30 17:42:02.402 7560-7560/? E/memtrack﹕ Couldn't load memtrack module (No such file or directory)
06-30 17:42:02.402 7560-7560/? E/android.os.Debug﹕ failed to load memtrack module: -2
06-30 17:42:02.460 7560-7570/? E/art﹕ Thread attaching while runtime is shutting down: Binder_1
Основная деятельность:
import android.app.ProgressDialog;
import android.content.Intent;
import android.content.res.Configuration;
import android.content.res.TypedArray;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.os.StrictMode;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.VolleyLog;
import com.android.volley.toolbox.JsonArrayRequest;
import com.boom.kayakapp.R;
import com.boom.kayakapp.adapters.AirlinesAdapter;
import com.boom.kayakapp.adapters.NavDrawerListAdapter;
import com.boom.kayakapp.controllers.AppController;
import com.boom.kayakapp.fragment.AirlinesFragment;
import com.boom.kayakapp.fragment.FavoriteFragment;
import com.boom.kayakapp.fragment.HomeFragment;
import com.boom.kayakapp.model.Airlines;
import com.boom.kayakapp.model.NavDrawerItem;
import com.boom.kayakapp.util.SharedPreference;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends ActionBarActivity {
private Fragment contentFragment;
AirlinesFragment airlinesFragment;
FavoriteFragment favoriteFragment;
// JSON Node names
public static final String TAG_NAME = "name";
public static final String TAG_PHONE = "phone";
public static final String TAG_SITE = "site";
public static final String TAG_LOGO = "logoURL";
public static final String TAG_CODE = "code";
// Log tag
private static final String TAG = MainActivity.class.getSimpleName();
// Airlines json url
private static final String url = "https://www.kayak.com/h/mobileapis/directory/airlines";
public ProgressDialog pDialog;
public List<Airlines> airlinesList = new ArrayList<Airlines>();
public ListView listView;
public AirlinesAdapter adapterAirlines;
SharedPreference sharedPreference;
// DrawerLayout
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 adapterDrawer;
@Override
protected void onCreate (Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
// SharedPrefs
sharedPreference = new SharedPreference();
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
// Json Array
listView = (ListView) findViewById(R.id.list);
adapterAirlines = new AirlinesAdapter(this, airlinesList);
listView.setAdapter(adapterAirlines);
pDialog = new ProgressDialog(this);
// Showing progress dialog before making http request
pDialog.setMessage("Loading...");
pDialog.show();
// Listview OnItemClickListener
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String name = ((TextView) view.findViewById(R.id.name))
.getText().toString();
String phone = ((TextView) view.findViewById(R.id.phone))
.getText().toString();
String site = ((TextView) view.findViewById(R.id.site))
.getText().toString();
String logoURL = String.valueOf(((ImageView) view.findViewById(R.id.logoURL)));
// Starting single contact activity
Intent in = new Intent(getApplicationContext(),
SingleContactActivity.class);
in.putExtra(TAG_NAME, name);
in.putExtra(TAG_PHONE, phone);
in.putExtra(TAG_SITE, site);
in.putExtra(TAG_LOGO, logoURL);
startActivity(in);
}
});
listView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> parent, View view,
int position, long id) {
ImageView button = (ImageView) view.findViewById(R.id.favorite_button);
String tag = button.getTag().toString();
if (tag.equalsIgnoreCase("grey")) {
sharedPreference.addFavorite(MainActivity.this, airlinesList.get(position));
Toast.makeText(MainActivity.this,
MainActivity.this.getResources().getString(R.string.add_favr),
Toast.LENGTH_SHORT).show();
button.setTag("red");
button.setImageResource(R.drawable.heart_red);
} else {
sharedPreference.removeFavorite(MainActivity.this, airlinesList.get(position));
button.setTag("grey");
button.setImageResource(R.drawable.heart_grey);
Toast.makeText(MainActivity.this,
MainActivity.this.getResources().getString(R.string.remove_favr),
Toast.LENGTH_SHORT).show();
}
return true;
}
});
// changing action bar color
getSupportActionBar().setBackgroundDrawable(
new ColorDrawable(Color.parseColor("#1b1b1b")));
// Creating volley request obj
JsonArrayRequest airlinesReq = new JsonArrayRequest(url,
new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
Log.d(TAG, response.toString());
hidePDialog();
// Parsing json
for (int i = 0; i < response.length(); i++) {
try {
JSONObject obj = response.getJSONObject(i);
Airlines airlines = new Airlines();
airlines.setName(obj.getString("name"));
airlines.setLogoURL(obj.getString("logoURL"));
airlines.setPhone(obj.getString("phone"));
airlines.setCode(obj.getInt("code"));
airlines.setSite(obj.getString("site"));
// adding airlines to array
airlinesList.add(airlines);
} catch (JSONException e) {
e.printStackTrace();
}
}
// notifying list adapterAirlines about data changes
// so that it renders the list view with updated data
adapterAirlines.notifyDataSetChanged();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
hidePDialog();
}
});
// Adding request to request queue
AppController.getInstance().addToRequestQueue(airlinesReq);
FragmentManager fragmentManager = getSupportFragmentManager();
/*
* This is called when orientation is changed.
*/
if (savedInstanceState != null) {
if (savedInstanceState.containsKey("content")) {
String content = savedInstanceState.getString("content");
if (content.equals(FavoriteFragment.ARG_ITEM_ID)) {
if (fragmentManager.findFragmentByTag(FavoriteFragment.ARG_ITEM_ID) != null) {
setFragmentTitle(R.string.favorites);
contentFragment = fragmentManager
.findFragmentByTag(FavoriteFragment.ARG_ITEM_ID);
}
}
}
if (fragmentManager.findFragmentByTag(AirlinesFragment.ARG_ITEM_ID) != null) {
airlinesFragment = (AirlinesFragment) fragmentManager
.findFragmentByTag(AirlinesFragment.ARG_ITEM_ID);
contentFragment = airlinesFragment;
}
} else {
airlinesFragment = new AirlinesFragment();
switchContent(airlinesFragment, AirlinesFragment.ARG_ITEM_ID);
}
/*
From this place DrawerLayout starts
*/
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)));
// Favorites
navDrawerItems.add(new NavDrawerItem(navMenuTitles[1], navMenuIcons.getResourceId(1, -1)));
// Recycle the typed array
navMenuIcons.recycle();
// setting the nav drawer list adapterDrawer
adapterDrawer = new NavDrawerListAdapter(getApplicationContext(),
navDrawerItems);
mDrawerList.setAdapter(adapterDrawer);
// enabling action bar app icon and behaving it as toggle button
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().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) {
getSupportActionBar().setTitle(mTitle);
// calling onPrepareOptionsMenu() to show action bar icons
invalidateOptionsMenu();
}
public void onDrawerOpened(View drawerView) {
getSupportActionBar().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);
}
}
@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);
// }
//
switch (item.getItemId()) {
case R.id.action_settings:
setFragmentTitle(R.string.favorites);
favoriteFragment = new FavoriteFragment();
switchContent(favoriteFragment, FavoriteFragment.ARG_ITEM_ID);
return true;
}
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 FavoriteFragment();
break;
default:
break;
}
if (fragment != null) {
FragmentManager fragmentManager = getSupportFragmentManager();
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;
getSupportActionBar().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);
}
@Override
public void onDestroy () {
super.onDestroy();
hidePDialog();
}
private void hidePDialog() {
if (pDialog != null) {
pDialog.dismiss();
pDialog = null;
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
protected void onSaveInstanceState(Bundle outState) {
if (contentFragment instanceof FavoriteFragment) {
outState.putString("content", FavoriteFragment.ARG_ITEM_ID);
} else {
outState.putString("content", AirlinesFragment.ARG_ITEM_ID);
}
super.onSaveInstanceState(outState);
}
public void switchContent(Fragment fragment, String tag) {
FragmentManager fragmentManager = getSupportFragmentManager();
while (fragmentManager.popBackStackImmediate()) ;
if (fragment != null) {
FragmentTransaction transaction = fragmentManager
.beginTransaction();
transaction.replace(R.id.content_frame, fragment, tag);
//Only FavoriteFragment is added to the back stack.
if (!(fragment instanceof AirlinesFragment)) {
transaction.addToBackStack(tag);
}
transaction.commit();
contentFragment = fragment;
}
}
protected void setFragmentTitle(int resourseId) {
setTitle(resourseId);
getSupportActionBar().setTitle(resourseId);
}
/*
* We call super.onBackPressed(); when the stack entry count is > 0. if it
* is instanceof ProductListFragment or if the stack entry count is == 0, then
* we finish the activity.
* In other words, from AirlinesFragment on back press it quits the app.
*/
@Override
public void onBackPressed() {
FragmentManager fm = getSupportFragmentManager();
if (fm.getBackStackEntryCount() > 0) {
super.onBackPressed();
} else if (contentFragment instanceof AirlinesFragment
|| fm.getBackStackEntryCount() == 0) {
finish();
}
}
@Override
public void onResume() {
super.onResume();
}
}
FavoriteFragment:
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemLongClickListener;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.Toast;
import com.boom.kayakapp.R;
import com.boom.kayakapp.adapters.AirlinesAdapter;
import com.boom.kayakapp.model.Airlines;
import com.boom.kayakapp.util.SharedPreference;
import java.util.List;
public class FavoriteFragment extends Fragment {
public static final String ARG_ITEM_ID = "favorite_list";
ListView favoriteList;
SharedPreference sharedPreference;
List<Airlines> favorites;
Activity activity;
AirlinesAdapter airlinesAdapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
activity = getActivity();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.activity_list, container,
false);
// Get favorite items from SharedPreferences.
sharedPreference = new SharedPreference();
favorites = sharedPreference.getFavorites(activity);
if (favorites == null) {
showAlert(getResources().getString(R.string.no_favorites_items),
getResources().getString(R.string.no_favorites_msg));
} else {
if (favorites.size() == 0) {
showAlert(
getResources().getString(R.string.no_favorites_items),
getResources().getString(R.string.no_favorites_msg));
}
favoriteList = (ListView) view.findViewById(R.id.list);
if (favorites != null) {
airlinesAdapter = new AirlinesAdapter(activity, favorites);
favoriteList.setAdapter(airlinesAdapter);
favoriteList.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View arg1,
int position, long arg3) {
}
});
favoriteList
.setOnItemLongClickListener(new OnItemLongClickListener() {
@Override
public boolean onItemLongClick(
AdapterView<?> parent, View view,
int position, long id) {
ImageView button = (ImageView) view
.findViewById(R.id.favorite_button);
String tag = button.getTag().toString();
if (tag.equalsIgnoreCase("grey")) {
sharedPreference.addFavorite(activity,
favorites.get(position));
Toast.makeText(
activity,
activity.getResources().getString(
R.string.add_favr),
Toast.LENGTH_SHORT).show();
button.setTag("red");
button.setImageResource(R.drawable.heart_red);
} else {
sharedPreference.removeFavorite(activity,
favorites.get(position));
button.setTag("grey");
button.setImageResource(R.drawable.heart_grey);
airlinesAdapter.remove(favorites
.get(position));
Toast.makeText(
activity,
activity.getResources().getString(
R.string.remove_favr),
Toast.LENGTH_SHORT).show();
}
return true;
}
});
}
}
return view;
}
public void showAlert(String title, String message) {
if (activity != null && !activity.isFinishing()) {
AlertDialog alertDialog = new AlertDialog.Builder(activity)
.create();
alertDialog.setTitle(title);
alertDialog.setMessage(message);
alertDialog.setCancelable(false);
// setting OK Button
alertDialog.setButton(AlertDialog.BUTTON_POSITIVE, "OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
// activity.finish();
getFragmentManager().popBackStackImmediate();
}
});
alertDialog.show();
}
}
@Override
public void onResume() {
getActivity().setTitle(R.string.favorites);
super.onResume();
}
}
1 ответ
Решение
Ошибка выглядит довольно понятной для меня.
java.lang.NullPointerException: попытка вызвать виртуальный метод 'java.lang.Object android.widget.ImageView.getTag()' для ссылки на пустой объект
Кнопка, которую вы пытаетесь найти по идентификатору после долгого щелчка, возвращает ноль, поэтому вы не можете использовать getTag() метод на этом объекте.
ImageView button = (ImageView) view.findViewById(R.id.favorite_button);
Поэтому вам следует проверить, действительно ли список избранных содержит вид (кнопку) с этим идентификатором. Попробуйте использовать getActivity().findViewByID() вместо этого, чтобы проверить это.