我设置的计数会在每次用户执行操作时递增。在特定计数之后，我会通过在数据库节点引用上调用setValue（）将该值保存到firebase。这导致我的片段重置。看起来onCreateView（）再次被调用。
当我看到currentQuestion计数不断重置为0时，我发现了这一点。我在onCreateView（）中添加了一个日志语句，每次保存到firebase时都会打印log语句。我不知道出了什么问题，firebase强迫我的观点以某种方式重新渲染吗？
public class GamePlayFragment extends Fragment实现了View.OnClickListener {
private DatabaseReference mDatabase;
private FirebaseUser firebaseUser;
private ValueEventListener gamePlayValueEventListenerRef;
private boolean isPlayerOne;
private int correctAnswers;
private List<MashapeQuestion> questionsList;
private List<Boolean> playerAnswers;
private String gameKey;
private int currentQuestion;
private TextView timer;
private TextView question;
private Button choiceOneBtn;
private Button choiceTwoBtn;
private Button choiceThreeBtn;
private Button choiceFourBtn;
private Context mContext;
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_game_play, container, false);
Log.d("onCreateView", "Creating the onCreateView");
timer = view.findViewById(R.id.timer);
question = (TextView) view.findViewById(R.id.current_question);
choiceOneBtn = (Button) view.findViewById(R.id.choice_one);
choiceTwoBtn = (Button) view.findViewById(R.id.choice_two);
choiceThreeBtn = (Button) view.findViewById(R.id.choice_three);
choiceFourBtn = (Button) view.findViewById(R.id.choice_four);
choiceOneBtn.setOnClickListener(this);
choiceTwoBtn.setOnClickListener(this);
choiceThreeBtn.setOnClickListener(this);
choiceFourBtn.setOnClickListener(this);
Bundle args = getArguments();
gameKey = args.getString("gameKey");
playerAnswers = new ArrayList<>();
currentQuestion = 0;
isPlayerOne = false;
correctAnswers = 0;
firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
mDatabase = FirebaseDatabase.getInstance().getReference();
mContext = getContext();
//this listener is to reads all questions and choices in memory from Firebase.
//The first question is also set in Firebase.
mDatabase.child("games").child(gameKey).addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
Game game = dataSnapshot.getValue(Game.class);
if(game != null) {
//determine player one
if(game.getPlayerOne().equals(firebaseUser.getUid())) {
isPlayerOne = true;
}
Toast.makeText(mContext, Boolean.toString(isPlayerOne), Toast.LENGTH_SHORT).show();
questionsList = game.getQuestions();
changeQuestion(currentQuestion);
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
//IGNORE
}
});
//This listener is used for the game play
gamePlayValueEventListenerRef = mDatabase.child("games")
.child(gameKey)
.addValueEventListener(gamePlayValueEventListener);
//TODO: ADD PERMANENT TIMER TO GAME PLAY. THE TIMER SHOULD BE RESET AFTER BOTH PLAYERS SELECTS ANSWERS OR TIME RUNS OUT
return view;
}
/**
* This is the value event listener used for listening to all game play action.
* When a selects a answer choice the value event listener will be triggered saving
* the answers.
*/
ValueEventListener gamePlayValueEventListener = new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
Game game = dataSnapshot.getValue(Game.class);
if(game != null) {
//TODO: CHECK FOR UPDATED VALUE
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
};
/**
* Change questions when both user has selected an answer choice
* or when the timer is up. Update the UI with the new question.
*/
public void changeQuestion(int currentQuestion) {
if(currentQuestion <= 9) {
MashapeQuestion newQuestion = questionsList.get(currentQuestion);
question.setText(newQuestion.getQuestion());
choiceOneBtn.setText(newQuestion.getChooices().get(0));
choiceTwoBtn.setText(newQuestion.getChooices().get(1));
if(newQuestion.getChooices().size() > 2) {
choiceThreeBtn.setText(newQuestion.getChooices().get(2));
choiceFourBtn.setText(newQuestion.getChooices().get(3));
choiceThreeBtn.setVisibility(View.VISIBLE);
choiceFourBtn.setVisibility(View.VISIBLE);
}else {
choiceThreeBtn.setVisibility(View.GONE);
choiceFourBtn.setVisibility(View.GONE);
}
enableButtonClicks();
}
}
/**
* This is the onclick listener method to detect when user clicks on a answer. The
* user that clicked on an answer will update firebase with their new answer
* @param v the view that was clicked on
*/
@Override
public void onClick(View v) {
Toast.makeText(getContext(), Integer.toString(currentQuestion), Toast.LENGTH_SHORT).show();
switch(v.getId()) {
case R.id.choice_one:
handlerAnswerSelection(v);
break;
case R.id.choice_two:
handlerAnswerSelection(v);
break;
case R.id.choice_three:
handlerAnswerSelection(v);
break;
case R.id.choice_four:
handlerAnswerSelection(v);
break;
default:
//NOTHING TO DO HERE
break;
}
}
/**
* Method to display the next question once a user has selected an answer
* @param v
*/
public void handlerAnswerSelection(View v) {
disableButtonClick();
String userAnswer = ((Button)v).getText().toString();
String realAnswer = questionsList.get(currentQuestion).getAnswer();
if(userAnswer.equals(realAnswer)) {
playerAnswers.add(currentQuestion, true);
correctAnswers++;
}else {
playerAnswers.add(currentQuestion, false);
}
if(currentQuestion == 9) {
determineWinner();
}else {
currentQuestion++;
changeQuestion(currentQuestion);
}
}
/**
* Method to determine the winner and save all required data.
* - compare both players wrong to right to determine winner
* - set the new token count for both players
* - delete the game object
* - set the new win/loss record for both players
*/
public void determineWinner() {
Toast.makeText(getContext(), "You might have won", Toast.LENGTH_SHORT).show();
if(isPlayerOne) {
mDatabase.child("games").child(gameKey).child("playerOneAnswers").setValue(playerAnswers, new DatabaseReference.CompletionListener() {
@Override
public void onComplete(DatabaseError databaseError, DatabaseReference databaseReference) {
Toast.makeText(mContext, "wrote to db", Toast.LENGTH_SHORT).show();
}
});
}else {
mDatabase.child("games").child(gameKey).child("playerTwoAnswers").setValue(playerAnswers, new DatabaseReference.CompletionListener() {
@Override
public void onComplete(DatabaseError databaseError, DatabaseReference databaseReference) {
Toast.makeText(mContext, "player two wrote to db", Toast.LENGTH_SHORT).show();
}
});
}
}
@Override
public void onDestroyView() {
super.onDestroyView();
mDatabase.removeEventListener(gamePlayValueEventListenerRef);
}
}