收到消息时无法刷新列表视图
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【中文标题】收到消息时无法刷新列表视图【英文标题】：Unable to refresh listview on message received 【发布时间】：2019-12-21 09:06:47 【问题描述】：我是 android 开发的新手，我学到的一切都来自教程和 Stack Overflow。我的应用程序已经完成了 90%，但无法刷新从 API JSON 网页中提取的列表视图。
我已经阅读了与我的问题相关的所有文章，我遵循的每个过程要么使应用程序崩溃，要么什么也不做。
这是我的 MainActivity.java
public class MainActivity extends AppCompatActivity
private static final String tag = MainActivity.class.getSimpleName();
private List<DataSet> list = new ArrayList<DataSet>();
private ListView listView;
private Adapter adapter;
@Override
public boolean onCreateOptionsMenu(Menu menu)
getMenuInflater().inflate(R.menu.main_menu, menu);
return super.onCreateOptionsMenu(menu);
@Override
public boolean onOptionsItemSelected(MenuItem item)
int id = item.getItemId();
if (id == R.id.mybutton)
Intent intent = new Intent(MainActivity.this, SettingsActivity.class);
startActivity(intent);
return true;
return super.onOptionsItemSelected(item);
@Override
protected void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView) findViewById(R.id.list);
adapter = new Adapter(this, list);
listView.setAdapter(adapter);
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(MainActivity.this);
String ipadr = preferences.getString("signature", "0.0.0.0");
JsonArrayRequest jsonreq = new JsonArrayRequest("http://" + ipadr + "/android.php",
new Response.Listener<JSONArray>()
@Override
public void onResponse(JSONArray response)
for (int i = 0; i < response.length(); i++)
try
JSONObject obj = response.getJSONObject(i);
DataSet dataSet = new DataSet();
dataSet.setName(obj.getString("resident"));
dataSet.setImage(obj.getString("image"));
dataSet.setWorth(obj.getString("type"));
dataSet.setSource(obj.getString("starttime"));
list.add(dataSet);
catch (JSONException e)
e.printStackTrace();
adapter.notifyDataSetChanged();
, new Response.ErrorListener()
@Override
public void onErrorResponse(VolleyError error)
AlertDialog.Builder add = new AlertDialog.Builder(MainActivity.this);
add.setMessage(error.getMessage()).setCancelable(true);
AlertDialog alert = add.create();
alert.setTitle("Error: Unable to connect to Server");
alert.show();
);
Controller.getPermission().addToRequestQueue(jsonreq);
public class MessageReceiver extends FirebaseMessagingService
private static final int REQUEST_CODE = 1;
private static final int NOTIFICATION_ID = 6578;
private static final String TAG = "MyFirebaseMsgService";
public MessageReceiver()
super();
@Override
public void onMessageReceived(RemoteMessage remoteMessage)
super.onMessageReceived(remoteMessage);
Log.d(TAG, "From: " + remoteMessage.getFrom());
if (remoteMessage.getNotification() != null)
Log.d(TAG, "Message Notification Body: " + remoteMessage.getNotification().getBody());
final String title = remoteMessage.getData().get("title");
final String message = remoteMessage.getData().get("body");
finish();
startActivity(getIntent());
overridePendingTransition(0, 0);
showNotifications(title, message);
private void showNotifications(String title, String msg)
Intent i = new Intent(this, MainActivity.class);
NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
String NOTIFICATION_CHANNEL_ID = "my_channel_id_01";
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID, "My Notifications", NotificationManager.IMPORTANCE_MAX);
// Configure the notification channel.
notificationChannel.setDescription("Channel description");
notificationChannel.enableLights(true);
notificationChannel.setLightColor(Color.RED);
notificationChannel.setVibrationPattern(new long[]0, 1000, 500, 1000);
notificationChannel.enableVibration(true);
notificationManager.createNotificationChannel(notificationChannel);
NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, NOTIFICATION_CHANNEL_ID);
notificationBuilder.setAutoCancel(true)
.setDefaults(Notification.DEFAULT_ALL)
.setWhen(System.currentTimeMillis())
.setSmallIcon(R.drawable.rnifyround)
.setTicker("Hearty365")
// .setPriority(Notification.PRIORITY_MAX)
.setContentTitle(title)
.setContentText(msg)
.setContentInfo("Info");
notificationManager.notify(/*notification id*/1, notificationBuilder.build());
我的 JSON 输出示例
["image":"http://1.2.3.4/images/check.png","starttime":"2019-08-06 20:43:06","endtime":"2019-08-06 20:43:19","serial":"11298293","type":"Pendant","resident":"Resident Name","room":"APT 200","bed":"1","state":"closed","image":"http://1.2.3.4/images/check.png","starttime":"2019-08-05 20:39:26","endtime":"2019-08-05 20:39:39","serial":"11298293","type":"Pendant","resident":"Resident Name","room":"APT 200","bed":"1","state":"closed"]
我希望在收到通知并且应用程序处于前台时刷新我的列表视图。我还需要让它在滑动时刷新，但我仍在努力。
编辑
public class Adapter extends BaseAdapter
private Activity activity;
private LayoutInflater inflater;
private List<DataSet> DataList;
ImageLoader imageLoader = Controller.getPermission().getImageLoader();
public Adapter(Activity activity, List<DataSet> dataitem)
this.activity = activity;
this.DataList = dataitem;
@Override
public int getCount()
return DataList.size();
@Override
public Object getItem(int location)
return DataList.get(location);
@Override
public long getItemId(int position)
return position;
@Override
public View getView(int position, View convertView, ViewGroup parent)
if (inflater == null)
inflater = (LayoutInflater) activity
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null)
convertView = inflater.inflate(R.layout.listview, null);
if (imageLoader == null)
imageLoader = Controller.getPermission().getImageLoader();
NetworkImageView thumbNail = (NetworkImageView) convertView
.findViewById(R.id.thumbnail);
TextView name = (TextView) convertView.findViewById(R.id.name);
TextView worth = (TextView) convertView.findViewById(R.id.worth);
TextView source = (TextView) convertView.findViewById(R.id.source);
DataSet m = DataList.get(position);
thumbNail.setImageUrl(m.getImage(), imageLoader);
name.setText("Resdient: " + (m.getName()));
source.setText("Activated: " + (m.getSource()));
worth.setText("Call Type: " + (m.getWorth()));
return convertView;
【问题讨论】：
我会看看广播，这是让您的应用知道发生了什么事的好方法。您可以订阅关于您的活动 onResume 的广播，并在您离开活动时取消订阅（onStop/onPause）。并在收到正确类型的广播时更新您的适配器。你可以在这里阅读更多关于它们的信息：developer.android.com/guide/components/broadcasts 你能告诉我们你的适配器吗？ 我会看看广播。我已经更新了 Adapter.java。 @urukh 我能够让它与广播一起工作，所以谢谢。我正在做的一件事是将我的整个代码从我的 onCreate 方法复制到我的其他方法中以进行刷新。有没有更好的办法？ @MattSaiko 因为您的适配器与 var "list" 链接，您可以创建一个仅更新此列表的方法，然后调用 notifyDatasetChanged，无需每次都重新创建实例。我还建议将您的代码分解为更小的方法，这会使事情更容易理解和维护 【参考方案1】：我认为您应该创建refresh() contain your codes: fetch data, add to list and notifyDataSetChange 函数并在onCreate() 和onMessageReceived() 中调用它，并且不要完成并重新启动活动
【讨论】：
【参考方案2】：感谢@urukh，我能够通过广播完成这项工作。
在我的 MessageReciever Activity showMessage 方法中，我调用我的方法sendMessage();
sendMessage 方法
private void sendMessage()
Log.d("sender", "Broadcasting message");
Intent intent = new Intent("custom-event-name");
// You can also include some extra data.
intent.putExtra("message", "This is my message!");
LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
然后在我的 MainActivity 中
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver()
@Override
public void onReceive(Context context, Intent intent)
//Code to refresh listview
【讨论】：
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