我是android的新手，在不同的测试应用程序中测试我的技能。现在我试图从Json url获取数据并从Json的对象收藏列表中创建。 Gradle完成没有任何问题，但每次我的应用程序启动时，它都会崩溃并出现下一个错误：
尝试调用接口方法＆＃39; int java.util.List.size（）＆＃39;在空对象引用上
我用作教程的下一个资源：
用于共享首选项：http://androidopentutorials.com/android-how-to-store-list-of-values-in-sharedpreferences/
用于Json解析器：http://www.androidhive.info/2014/09/android-json-parsing-using-volley/
这是我的代码错误和活动，其中包含错误：
06-17 17:05:14.124 10249-10249/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.boom.kayakapp, PID: 10249
java.lang.ClassCastException: java.util.ArrayList cannot be cast to com.boom.kayakapp.model.Airlines
at com.boom.kayakapp.adapters.AirlinesListAdapter.getView(AirlinesListAdapter.java:102)
at android.widget.AbsListView.obtainView(AbsListView.java:2347)
at android.widget.ListView.measureHeightOfChildren(ListView.java:1270)
at android.widget.ListView.onMeasure(ListView.java:1182)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at android.support.v7.internal.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:124)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.support.v7.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:444)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2615)
at android.view.View.measure(View.java:17547)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2015)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1173)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1379)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1061)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5885)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
at android.view.Choreographer.doCallbacks(Choreographer.java:580)
at android.view.Choreographer.doFrame(Choreographer.java:550)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
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)
06-17 17:05:14.153 932-932/? E/EGL_emulation﹕ tid 932: eglCreateSyncKHR(1237): error 0x3004 (EGL_BAD_ATTRIBUTE)
06-17 17:05:16.543 1233-1266/system_process E/InputDispatcher﹕ channel '26e93136 com.boom.kayakapp/com.boom.kayakapp.activities.MainActivity (server)' ~ Channel is unrecoverably broken and will be disposed!
06-17 17:05:38.432 10506-10506/? E/memtrack﹕ Couldn't load memtrack module (No such file or directory)
06-17 17:05:38.432 10506-10506/? E/android.os.Debug﹕ failed to load memtrack module: -2
06-17 17:05:39.009 10523-10523/? E/memtrack﹕ Couldn't load memtrack module (No such file or directory)
06-17 17:05:39.009 10523-10523/? E/android.os.Debug﹕ failed to load memtrack module: -2
06-17 17:05:51.855 10533-10533/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.boom.kayakapp, PID: 10533
java.lang.ClassCastException: java.util.ArrayList cannot be cast to com.boom.kayakapp.model.Airlines
at com.boom.kayakapp.adapters.AirlinesListAdapter.getView(AirlinesListAdapter.java:102)
at android.widget.AbsListView.obtainView(AbsListView.java:2347)
at android.widget.ListView.measureHeightOfChildren(ListView.java:1270)
at android.widget.ListView.onMeasure(ListView.java:1182)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at android.support.v7.internal.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:124)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.support.v7.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:444)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
at android.view.View.measure(View.java:17547)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5535)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2615)
at android.view.View.measure(View.java:17547)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2015)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1173)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1379)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1061)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5885)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
at android.view.Choreographer.doCallbacks(Choreographer.java:580)
at android.view.Choreographer.doFrame(Choreographer.java:550)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5257)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
06-17 17:05:51.887 932-932/? E/EGL_emulation﹕ tid 932: eglCreateSyncKHR(1237): error 0x3004 (EGL_BAD_ATTRIBUTE)
06-17 17:06:51.514 11046-11046/? E/memtrack﹕ Couldn't load memtrack module (No such file or directory)
06-17 17:06:51.514 11046-11046/? E/android.os.Debug﹕ failed to load memtrack module: -2
06-17 17:06:52.206 11063-11063/? E/memtrack﹕ Couldn't load memtrack module (No such file or directory)
06-17 17:06:52.207 11063-11063/? E/android.os.Debug﹕ failed to load memtrack module: -2
06-17 17:07:03.184 932-932/? E/EGL_emulation﹕ tid 932: eglCreateSyncKHR(1237): error 0x3004 (EGL_BAD_ATTRIBUTE)
06-17 17:07:06.919 1233-1266/system_process E/InputDispatcher﹕ channel '3bd6cfb7 com.boom.kayakapp/com.boom.kayakapp.activities.MainActivity (server)' ~ Channel is unrecoverably broken and will be disposed!
AirlinesListAdapter：
package com.boom.kayakapp.adapters;
import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.NetworkImageView;
import com.boom.kayakapp.R;
import com.boom.kayakapp.controllers.AppController;
import com.boom.kayakapp.model.Airlines;
import com.boom.kayakapp.util.SharedPreference;
import java.util.ArrayList;
import java.util.List;
public class AirlinesListAdapter extends ArrayAdapter<Airlines> {
private Activity activity;
private List<Airlines> favorites;
private LayoutInflater inflater;
SharedPreference sharedPreference;
ImageLoader imageLoader = AppController.getInstance().getImageLoader();
public AirlinesListAdapter(Activity activity, List<Airlines> favorites) {
super(activity, R.layout.list_item, favorites);
this.activity = activity;
if(favorites == null)
favorites = new ArrayList<>();
else
this.favorites = favorites;
sharedPreference = new SharedPreference();
}
private class ViewHolder {
ImageView favoriteImg;
}
@Override
public int getCount() {
return favorites.size();
}
@Override
public Airlines getItem(int location) {
return favorites.get(location);
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
if (inflater == null)
inflater = (LayoutInflater) activity
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null)
convertView = inflater.inflate(R.layout.list_item, null);
holder = new ViewHolder();
if (imageLoader == null)
imageLoader = AppController.getInstance().getImageLoader();
NetworkImageView logoURL = (NetworkImageView) convertView
.findViewById(R.id.logoURL);
TextView name = (TextView) convertView.findViewById(R.id.name);
TextView phone = (TextView) convertView.findViewById(R.id.phone);
TextView site = (TextView) convertView.findViewById(R.id.site);
TextView code = (TextView) convertView.findViewById(R.id.code);
holder.favoriteImg = (ImageView) convertView
.findViewById(R.id.favorite_button);
// getting airlines data for the row
Airlines m = favorites.get(position);
// thumbnail image
logoURL.setImageUrl(m.getLogoURL(), imageLoader);
// name
name.setText(m.getName());
// phone
phone.setText("Phone: " + String.valueOf(m.getPhone()));
// site
site.setText("Web: " + String.valueOf(m.getSite()));
// release code
code.setText(String.valueOf(m.getCode()));
/*If a product exists in shared preferences then set heart_red drawable
* and set a tag*/
if (checkFavoriteItem((Airlines) favorites)) {
holder.favoriteImg.setImageResource(R.drawable.heart_red);
holder.favoriteImg.setTag("red");
} else {
holder.favoriteImg.setImageResource(R.drawable.heart_grey);
holder.favoriteImg.setTag("grey");
}
return convertView;
}
/*Checks whether a particular product exists in SharedPreferences*/
public boolean checkFavoriteItem(Airlines checkAirlines) {
boolean check = false;
// List<Airlines> favorites = sharedPreference.getFavorites(activity);
if (favorites != null) {
for (Airlines product : favorites) {
if (product.equals(checkAirlines)) {
check = true;
break;
}
}
}
return check;
}
@Override
public void add(Airlines airlines) {
super.add(airlines);
favorites.add(airlines);
notifyDataSetChanged();
}
@Override
public void remove(Airlines airlines) {
super.remove(airlines);
favorites.remove(airlines);
notifyDataSetChanged();
}
}
AirlineListFragment：
package com.boom.kayakapp.fragment;
import android.app.Activity;
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.OnItemLongClickListener;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.Toast;
import com.boom.kayakapp.R;
import com.boom.kayakapp.adapters.AirlinesListAdapter;
import com.boom.kayakapp.model.Airlines;
import com.boom.kayakapp.util.SharedPreference;
import java.util.ArrayList;
import java.util.List;
public class AirlinesListFragment extends Fragment implements OnItemLongClickListener, AdapterView.OnItemClickListener {
public static final String ARG_ITEM_ID = "airlines_list";
Activity activity;
ListView airlinesListView;
List<Airlines> airlines;
AirlinesListAdapter airlinesListAdapter;
public AirlinesListFragment() {
airlines = new ArrayList<>();
}
SharedPreference sharedPreference;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
activity = getActivity();
sharedPreference = new SharedPreference();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_airlines_list, container,
false);
findViewsById(view);
airlinesListAdapter = new AirlinesListAdapter(activity, airlines);
airlinesListView.setAdapter(airlinesListAdapter);
airlinesListView.setOnItemClickListener(this);
airlinesListView.setOnItemLongClickListener(this);
return view;
}
private void findViewsById(View view) {
airlinesListView = (ListView) view.findViewById(R.id.list_airlines);
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
Airlines airlines = (Airlines) parent.getItemAtPosition(position);
Toast.makeText(activity, airlines.toString(), Toast.LENGTH_LONG).show();
}
@Override
public boolean onItemLongClick(AdapterView<?> arg0, View view,
int position, long arg3) {
ImageView button = (ImageView) view.findViewById(R.id.favorite_button);
String tag = button.getTag().toString();
if (tag.equalsIgnoreCase("grey")) {
sharedPreference.addFavorite(activity, airlines.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, airlines.get(position));
button.setTag("grey");
button.setImageResource(R.drawable.heart_grey);
Toast.makeText(activity,
activity.getResources().getString(R.string.remove_favr),
Toast.LENGTH_SHORT).show();
}
return true;
}
@Override
public void onResume() {
getActivity().setTitle(R.string.app_name);
getActivity().getActionBar().setTitle(R.string.app_name);
super.onResume();
}
}
MainActivity：
package com.boom.kayakapp.activities;
import android.app.ProgressDialog;
import android.content.Intent;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
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 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.AirlinesListAdapter;
import com.boom.kayakapp.controllers.AppController;
import com.boom.kayakapp.fragment.AirlinesListFragment;
import com.boom.kayakapp.fragment.FavoriteListFragment;
import com.boom.kayakapp.model.Airlines;
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;
AirlinesListFragment airlinesListFragment;
FavoriteListFragment favoriteListFragment;
// 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 AirlinesListAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.list);
adapter = new AirlinesListAdapter(this, airlinesList);
listView.setAdapter(adapter);
pDialog = new ProgressDialog(this);
// Showing progress dialog before making http request
pDialog.setMessage("Loading...");
pDialog.show();
// Listview on item click listener
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);
}
});
// 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 movies array
airlinesList.add(airlines);
} catch (JSONException e) {
e.printStackTrace();
}
}
// notifying list adapter about data changes
// so that it renders the list view with updated data
adapter.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(FavoriteListFragment.ARG_ITEM_ID)) {
if (fragmentManager.findFragmentByTag(FavoriteListFragment.ARG_ITEM_ID) != null) {
setFragmentTitle(R.string.favorites);
contentFragment = fragmentManager
.findFragmentByTag(FavoriteListFragment.ARG_ITEM_ID);
}
}
}
if (fragmentManager.findFragmentByTag(AirlinesListFragment.ARG_ITEM_ID) != null) {
airlinesListFragment = (AirlinesListFragment) fragmentManager
.findFragmentByTag(AirlinesListFragment.ARG_ITEM_ID);
contentFragment = airlinesListFragment;
}
} else {
airlinesListFragment = new AirlinesListFragment();
// setFragmentTitle(R.string.app_name);
switchContent(airlinesListFragment, AirlinesListFragment.ARG_ITEM_ID);
}
}
@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 FavoriteListFragment) {
outState.putString("content", FavoriteListFragment.ARG_ITEM_ID);
} else {
outState.putString("content", AirlinesListFragment.ARG_ITEM_ID);
}
super.onSaveInstanceState(outState);
}
// @Override
// public boolean onCreateOptionsMenu(Menu menu) {
// getMenuInflater().inflate(R.menu.main, menu);
// return true;
// }
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_favorites:
setFragmentTitle(R.string.favorites);
favoriteListFragment = new FavoriteListFragment();
switchContent(favoriteListFragment, FavoriteListFragment.ARG_ITEM_ID);
return true;
}
return super.onOptionsItemSelected(item);
}
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 FavoriteListFragment is added to the back stack.
if (!(fragment instanceof AirlinesListFragment)) {
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 ProductListFragment on back press it quits the app.
*/
@Override
public void onBackPressed() {
FragmentManager fm = getSupportFragmentManager();
if (fm.getBackStackEntryCount() > 0) {
super.onBackPressed();
} else if (contentFragment instanceof AirlinesListFragment
|| fm.getBackStackEntryCount() == 0) {
finish();
}
}
}
型号：
package com.boom.kayakapp.model;
public class Airlines {
private String name, logoURL, phone, site;
private int code;
public Airlines() {
}
public Airlines
(String name, String logoURL, int code, String phone, String site) {
this.name = name;
this.logoURL = logoURL;
this.code = code;
this.phone = phone;
this.site = site;
}
public String getName() {return name;}
public void setName(String name) {this.name = name;}
public String getLogoURL() {return logoURL;}
public void setLogoURL(String logoURL) {this.logoURL = logoURL;}
public int getCode() {return code;}
public void setCode(Integer code) {this.code = code;}
public String getPhone() {return phone;}
public void setPhone(String phone) {this.phone = phone;}
public String getSite() {return site;}
public void setSite(String site) {this.site = site;}
}
答案 0 :(得分：0)
setAdapter调用getCount但列表为null所以只需像这样启动航空公司列表
public AirlinesListAdapter(Activity activity, List<Airlines> favorites) {
super(activity, R.layout.list_item, favorites);
this.activity = activity;
if(favorites == null)
favorites = new ArrayList<>();
else
this.favorites = favorites;
sharedPreference = new SharedPreference();
}
第二种解决方案： 在片段中初始化数组
public AirlinesListFragment() {
airlines = new ArrayList<>();
}
这应该可以解决你的问题
查看此页面了解解决方案：Can't get Action Bar in fragment class