我正在为我的应用构建一个小部件,以便从Firestore获取一些数据。唯一的问题是,如果我将onDataSetChanged留空,我能够最初在onCreate中成功获取数据。
我相信onDataSetChanged会在一段时间后被OS调用来刷新。所以我不想把这个功能留空。
但问题是我无法在没有无限递归的情况下更新onDataSetChanged中的小部件,因为我正在使用notifyAppWidgetViewDataChanged刷新我的小部件来显示从Firestore获取的新文档。
所以我的问题是如何在我的firebase查询的回调函数中没有notifyAppWidgetViewDataChanged的情况下刷新小部件?
谢谢
public class TaskWidgetService extends RemoteViewsService {
@Override
public RemoteViewsFactory onGetViewFactory(Intent intent) {
return new TaskWidgetItemFactory(getApplicationContext(), intent);
}
class TaskWidgetItemFactory implements RemoteViewsFactory {
public static final String TAG = "TaskWidgetItemFactory";
private Context context;
private int appWidgetID;
private ArrayList<String> tasksArrayList; //tasks I want to show
public TaskWidgetItemFactory(Context context, Intent intent) {
this.context = context;
this.appWidgetID = intent.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID);
}
void initializeData() {
Log.d(TAG, "initializeData: I'm being called.....");
try {
//Initialize ALL Firebase components
FirebaseFirestore db = FirebaseFirestore.getInstance();
FirebaseAuth mFirebaseAuth = FirebaseAuth.getInstance();
String userId = mFirebaseAuth.getCurrentUser().getUid();
final int a = this.appWidgetID;
Query tasksQuery = db
.collection("users/" + userId + "/tasks")
.orderBy(Task.FIRESTORE_FIELD_DUE_TIMESTAMP, Query.Direction.ASCENDING)
.orderBy(Task.FIRESTORE_FIELD_PROGRESS, Query.Direction.ASCENDING)
.whereEqualTo(Task.FIRESTORE_FIELD_PARENT_TASK_DOC_ID, null) // only want Parent Tasks
;
tasksQuery.get()
.addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
@Override
public void onComplete(@NonNull com.google.android.gms.tasks.Task<QuerySnapshot> task) {
if (task.isSuccessful()) {
for (QueryDocumentSnapshot document : task.getResult()) {
Log.d(TAG, document.getId() + " => " + document.get("name"));
Task t = document.toObject(Task.class);
tasksArrayList.add(t.toString()); //add item to show
}
//refresh Widget to show the data.
AppWidgetManager appWidgetManager = **AppWidgetManager.getInstance(context);
appWidgetManager.notifyAppWidgetViewDataChanged(a, R.id.task_widget_stack_view);**
} else {
Log.d(TAG, "Error getting documents: ", task.getException());
}
}
});
} catch (Exception e) {
Log.d(TAG, "initializeData: " + e.toString());
}
}
@Override
public void onCreate() {
tasksArrayList = new ArrayList<>();
initializeData();//get data
}
@Override
public void onDataSetChanged() {
tasksArrayList = new ArrayList<>();
initializeData(); //get data causes infinte recursion b/c of "notifyAppWidgetViewDataChanged"
}
@Override
public int getCount() {
Log.d(TAG, "getCount: " + tasksArrayList.size());
return tasksArrayList.size();
}
}}
if(yourList!= null){
yourList.clear();
}
最后你可以打电话
adapter.notifydatasetChanged();
我能够通过使用await获取onDataSetChanged()中的数据来修复它。
@Override
public void onDataSetChanged() {
tasksArrayList = new ArrayList<>();
FirebaseFirestore db = FirebaseFirestore.getInstance();
FirebaseAuth mFirebaseAuth = FirebaseAuth.getInstance();
String userId = mFirebaseAuth.getCurrentUser().getUid();
Query tasksQuery = db
.collection("users/" + userId + "/tasks")
.orderBy(Task.FIRESTORE_FIELD_DUE_TIMESTAMP, Query.Direction.ASCENDING)
.orderBy(Task.FIRESTORE_FIELD_PROGRESS, Query.Direction.ASCENDING)
.whereEqualTo(Task.FIRESTORE_FIELD_PARENT_TASK_DOC_ID, null) // only want Parent Tasks
;
try {
//wait for data to be collected.
final QuerySnapshot querySnapshot = Tasks.await(tasksQuery.get());
for (QueryDocumentSnapshot document : querySnapshot) {
Log.d(TAG, document.getId() + " => " + document.get("name"));
Task t = document.toObject(Task.class);
tasksArrayList.add(t);
}
} catch (ExecutionException e) {
Toast.makeText(getApplicationContext(), "Failed to get Tasks.", Toast.LENGTH_LONG).show();
} catch (InterruptedException e) {
Toast.makeText(getApplicationContext(), "Failed to get Tasks.", Toast.LENGTH_LONG).show();
}
}