Я использую дочерний обработчик событий для получения данных из базы данных.У меня была проблема с отображением данных в представлении рециркулятора, и после долгих часов отладки я обнаружил, что причина проблемы в том, что onChildChanged вызывается при добавлении нового дочернего элемента.
это код, который даетданные из базы данных:
public void startAsynkTask() {
//TODO : search for a solution to this error
AsyncTask asyncTask = new AsyncTask() {
@Override
protected Boolean doInBackground(Object[] objects) {
try {
Socket sock = new Socket();
sock.connect(new InetSocketAddress("8.8.8.8", 53), 1500);
sock.close();
return true;
} catch (IOException e) {
return false;
}
}
@Override
protected void onPostExecute(Object o) {
if ((boolean) o) {
recreatingLists();
ChildEventListener generalChallengesListener = new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
Log.v("onChildAdded", "child added");
getChallengeData(dataSnapshot, "onChildAdded");
view.onDataFound();
}
@Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
//TODO : note that the only changing handled is when challenge moves from uncompleted to completed state
if(!dataSnapshot.getKey().equals("questionsList")){
getChallengeData(dataSnapshot, "onChildChanged");
}
for (int i = 0; i < uncompletedChallengesList.size(); i++) {
if (uncompletedChallengesList.get(i).getId().equals(dataSnapshot.getKey())) {
uncompletedChallengesList.remove(i);
view.notifyAdapters(completedChallengesList.size(), uncompletedChallengesList.size(), "onChildChanged");
break;
}
}
checkListsSizeAndAdjustViews();
view.hideProgressBar();
}
@Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
startAsynkTask();
}
@Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
@Override
public void onCancelled(DatabaseError databaseError) {
//Toast.makeText(getActivity(), "فشل تحميل البيانات من فضلك تأكد من الاتصال بالانترنت", Toast.LENGTH_SHORT).show();
view.hideProgressBar();
Log.v("Logging", "error loading data : " + databaseError);
}
};
//this code gives data where current user is player 1
player1Listener = challengesReference.orderByChild("player1Uid").equalTo(currentUserUid).addChildEventListener(generalChallengesListener);
//this code gives data where current user is player 2
player2Listener = challengesReference.orderByChild("player2Uid").equalTo(currentUserUid).addChildEventListener(generalChallengesListener);
challengesReference.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
onInitialDataLoaded();
Log.v("ChallengesFragPresenter", "completed list size :" + completedChallengesList + " , uncompleted list size : " + uncompletedChallengesList);
challengesReference.removeEventListener(this);
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
} else {
view.onNoInternetConnection();
}
}
};
asyncTask.execute();
}
public String getChallengeData(DataSnapshot dataSnapshot, String tag) {
Log.v("ChallengesFragPresenter", "get challenge data called");
Log.v("ChallengesFragPresenter", "completedChallengesList : " + completedChallengesList.size()
+ ", uncompletedChallengesList " + uncompletedChallengesList.size());
view.startCompletedChallengesAdapter(completedChallengesList);
view.startUnCompletedChallengesAdapter(uncompletedChallengesList);
GenericTypeIndicator<List<Question>> t = new GenericTypeIndicator<List<Question>>() {
};
challenge = new Challenge();
String challengeDate = dataSnapshot.child("date").getValue().toString();
String challengeSubject = dataSnapshot.child("subject").getValue().toString();
String challengeState = dataSnapshot.child("state").getValue().toString();
String challengeId = dataSnapshot.getKey();
ArrayList challengeQuestionsList = (ArrayList) dataSnapshot.child("questionsList").getValue(t);
long player1Score = (long) dataSnapshot.child("player1score").getValue();
long player2Score = (long) dataSnapshot.child("player2score").getValue();
String player1Name = dataSnapshot.child("player1Name").getValue().toString();
String player1Image = dataSnapshot.child("player1Image").getValue().toString();
String player1Uid = dataSnapshot.child("player1Uid").getValue().toString();
String player2Name = dataSnapshot.child("player2Name").getValue().toString();
String player2Image = dataSnapshot.child("player2Image").getValue().toString();
String player2Uid = dataSnapshot.child("player2Uid").getValue().toString();
String challengerName, challengerImage;
if (player1Uid.equals(currentUserUid)) {
currentPlayer = 1;
challengerName = player2Name;
challengerImage = player2Image;
challenge.setSecondChallengerUid(player2Uid);//second means that it is not the player who starts the challenge
if (tag.equals("onChildAdded")) {
player1childrenCount++;
}
} else {
currentPlayer = 2;
challengerName = player1Name;
challengerImage = player1Image;
challenge.setSecondChallengerUid(player1Uid);//second means that it is not the player who starts the challenge
if (tag.equals("onChildAdded")) {
player2childrenCount++;
}
}
challenge.setCurrentPlayer(currentPlayer);
challenge.setChallengerName(challengerName);
challenge.setDate(challengeDate);
challenge.setImage(challengerImage);
challenge.setSubject(challengeSubject);
challenge.setState(challengeState);
challenge.setId(challengeId);
challenge.setPlayer1Score(player1Score);
challenge.setPlayer2Score(player2Score);
challenge.setQuestionsList(challengeQuestionsList);
String score;
if (currentPlayer == 1) {
score = player1Score + " : " + player2Score;
} else {
score = player2Score + " : " + player1Score;
}
challenge.setScore(score);
if (challenge.getState().equals("اكتمل")) {
Log.v("loggingC1", "value is " + !existsInCompletedChallengesList(challengeId));
if (!existsInCompletedChallengesList(dataSnapshot.getKey())) {
view.showCompletedChallengesTv();
completedChallengesList.add(0, challenge);
view.notifyAdapters(completedChallengesList.size(), uncompletedChallengesList.size(), "getChallengeData1");
}
}
else if (challenge.getState().equals(refusedChallengeText)) {
Log.v("loggingC2", "value is " + !existsInCompletedChallengesList(challengeId));
if (!existsInCompletedChallengesList(dataSnapshot.getKey())) {
view.showCompletedChallengesTv();
completedChallengesList.add(0, challenge);
view.notifyAdapters(completedChallengesList.size(), uncompletedChallengesList.size(), "getChallengeData3");
}
}
else if (challenge.getState().equals(uncompletedChallengeText)) {
Log.v("loggingC3", "value is " + !existsInUncompletedChallengesList(dataSnapshot.getKey()));
if (!existsInUncompletedChallengesList(challengeId)) {
view.showUncompletedChallengesTv();
uncompletedChallengesList.add(0, challenge);
view.notifyAdapters(completedChallengesList.size(), uncompletedChallengesList.size(), "getChallengeData2");
}
}
return player1Uid;
}
Я использую задачу asynk в начале, чтобы проверить подключение к Интернету, если есть подключение к Интернету, он начнет загружать данные.Изображение показывает структуру моих детей в базе данных
