我正在尝试在帖子中添加喜欢或不喜欢的功能（问题）。但这不是更新“赞”按钮图像。
public class QuestionDetailActivity extends AppCompatActivity implements View.OnClickListener {
private static final String TAG = "QuestionDetailActivity";
private Context mContext;
private TextView questionTitleTv;
private RadioGroup radioLL;
private EditText answerEt;
private LinearLayout checkboxLL;
private LinearLayout commentLL;
private FirebaseFirestore db = null;
private String questionID;
private String userID;
private TextView likeCountTv,favouriteCountTv;
private boolean isLikedByUser = false,isFavouriteByUser = false;
private DocumentReference questionRef;
private QuestionBO questionBO;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_question_detail);
mContext = QuestionDetailActivity.this;
db = FirebaseFirestore.getInstance();
userID = "V5BUeBFYR8WKOQUiBFxKrfMHK8Y2";
questionTitleTv = findViewById(R.id.tv_question_title);
radioLL = findViewById(R.id.ll_radio);
answerEt = findViewById(R.id.et_answer);
checkboxLL = findViewById(R.id.ll_checkbox);
commentLL = findViewById(R.id.ll_comments);
likeCountTv = findViewById(R.id.tv_like_count);
favouriteCountTv = findViewById(R.id.tv_favourite_count);
likeCountTv.setOnClickListener(this);
favouriteCountTv.setOnClickListener(this);
if (getIntent() != null) {
questionID = getIntent().getExtras().getString("keyQuestionID", "");
}
questionRef = db.collection("questionCollection").document(questionID);
if (!questionID.isEmpty()) {
getQuestionDetail();
///showComments();
updateFavouriteAndLikeIcons();
}
}
private void updateFavouriteAndLikeIcons() {
questionRef.collection("favouriteCollection").document(userID).get()
.addOnSuccessListener(new OnSuccessListener<DocumentSnapshot>() {
@Override
public void onSuccess(DocumentSnapshot documentSnapshot) {
if(documentSnapshot.exists()){
isFavouriteByUser = true;
// and make it blue
Drawable image = getResources().getDrawable( R.drawable.icn_fav_yes );
int h = image.getIntrinsicHeight();
int w = image.getIntrinsicWidth();
image.setBounds( 0, 0, w, h );
favouriteCountTv.setCompoundDrawables( image, null, null, null );
}
}
});
questionRef.collection("likeCollection").document(userID).get()
.addOnSuccessListener(new OnSuccessListener<DocumentSnapshot>() {
@Override
public void onSuccess(DocumentSnapshot documentSnapshot) {
if(documentSnapshot.exists()){
boolean isLiked = documentSnapshot.getBoolean(userID);
if(isLiked){
isLikedByUser = true;
// and make it blue
Drawable image = getResources().getDrawable( R.drawable.icn_like_yes );
int h = image.getIntrinsicHeight();
int w = image.getIntrinsicWidth();
image.setBounds( 0, 0, w, h );
likeCountTv.setCompoundDrawables( image, null, null, null );
}
else{//dislike
}
}
}
});
}
private void showComments() {
db.collection("commentCollection").whereEqualTo("questionID", questionID)
.get()
.addOnSuccessListener(new OnSuccessListener<QuerySnapshot>() {
@Override
public void onSuccess(QuerySnapshot queryDocumentSnapshots) {
if (queryDocumentSnapshots.isEmpty()) {
Log.d(TAG, "onSuccess: LIST EMPTY");
return;
} else {
// Convert the whole Query Snapshot to a list
// of objects directly! No need to fetch each
// document.
List<CommentBO> commentList = queryDocumentSnapshots.toObjects(CommentBO.class);
if (commentList != null && commentList.size() > 0) {
for (int x = 0; x < commentList.size(); x++) {
try {
LinearLayout.LayoutParams childParam = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
childParam.setMargins(20, 10, 0, 0);
View commentByView = LayoutInflater.from(mContext).inflate(R.layout.item_comment, null);
TextView tvCommenter = (TextView) commentByView.findViewById(R.id.item_tv_commenter_name);
TextView tvCommenterComment = (TextView) commentByView.findViewById(R.id.item_tv_commenter_comment);
TextView tvCommentDate = (TextView) commentByView.findViewById(R.id.item_tv_comment_date);
tvCommenter.setText(commentList.get(x).getCommentedBy());
tvCommenterComment.setText(commentList.get(x).getComment());
///tvCommentDate.setText();
commentLL.addView(commentByView, childParam);
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
}
});
}
private void getQuestionDetail() {
questionRef.get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
@Override
public void onComplete(@NonNull Task<DocumentSnapshot> task) {
if (task.isSuccessful()) {
DocumentSnapshot document = task.getResult();
if (document.exists()) {
Log.d(TAG, "DocumentSnapshot data: " + document.getData());
questionBO = document.toObject(QuestionBO.class);
updateView(questionBO);
} else {
Log.d(TAG, "No such document");
}
} else {
Log.d(TAG, "get failed with ", task.getException());
}
}
});
}
private void updateView(QuestionBO mQuestionBO) {
if (mQuestionBO != null) {
questionTitleTv.setText(mQuestionBO.getTitle());
likeCountTv.setText(mQuestionBO.getTotalLikes() + "");
favouriteCountTv.setText(mQuestionBO.getTotalFavourites() + "");
switch (mQuestionBO.getQuestionType()) {
case CHECKBOX:
checkboxLL.setVisibility(View.VISIBLE);
if (mQuestionBO.getOptions() != null && mQuestionBO.getOptions().size() > 0) {
checkboxLL.removeAllViews();
for (int x = 0; x < mQuestionBO.getOptions().size(); x++) {
final CheckBox subCheckbox = new CheckBox(mContext);
subCheckbox.setText(mQuestionBO.getOptions().get(x));
subCheckbox.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
}
});
checkboxLL.addView(subCheckbox, new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));
}
}
break;
case RADIO:
radioLL.setVisibility(View.VISIBLE);
if (mQuestionBO.getOptions() != null && mQuestionBO.getOptions().size() > 0) {
radioLL.removeAllViews();
for (int x = 0; x < mQuestionBO.getOptions().size(); x++) {
final RadioButton subRadio = new RadioButton(mContext);
subRadio.setText(mQuestionBO.getOptions().get(x));
radioLL.addView(subRadio, new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));
}
}
break;
case DESCRIPTIVE:
answerEt.setVisibility(View.VISIBLE);
break;
}
}
}
private void likeOrDislikeThisQuestion(){
final Task<Boolean> booleanTask = db.runTransaction(new Transaction.Function<Boolean>() {
@Nullable
@Override
public Boolean apply(@NonNull Transaction transaction) throws FirebaseFirestoreException {
DocumentReference likeRef = questionRef.collection("likeCollection")
.document(userID);
Map<String,Object> map = new HashMap<>();
DocumentSnapshot snapshot = transaction.get(likeRef);
if(snapshot.exists()){ // it means this is a favourite question of this user.
if(snapshot.getBoolean(questionID) && isLikedByUser){
isLikedByUser = false;
map.put(questionID,isLikedByUser);
transaction.update(likeRef,map);
int numberOfLikes = questionBO.getTotalLikes();
transaction.update(questionRef,"totalLikes",--numberOfLikes);
likeCountTv.setText(numberOfLikes + "");
return isLikedByUser;
}
else if(!snapshot.getBoolean(questionID) && !isLikedByUser){
isLikedByUser = true;
map.put(questionID,isLikedByUser);
transaction.update(likeRef,map);
int numberOfLikes = questionBO.getTotalLikes();
transaction.update(questionRef,"totalLikes",-++numberOfLikes);
likeCountTv.setText(numberOfLikes + "");
return isLikedByUser;
}
}
else {
isLikedByUser = !isLikedByUser;
map.put(questionID,isLikedByUser);// pass oposite of it..
transaction.set(likeRef,map);
int numberOfLikes = questionBO.getTotalLikes();
if(isLikedByUser)
++numberOfLikes;
else
--numberOfLikes;
transaction.update(questionRef,"totalLikes",numberOfLikes);
likeCountTv.setText(numberOfLikes + "");
return isLikedByUser;
}
return null;
}
});
booleanTask.addOnSuccessListener(new OnSuccessListener<Boolean>() {
@Override
public void onSuccess(Boolean isLiked) {
if(isLiked == null){
}
else if(isLiked){
Drawable image = getResources().getDrawable( R.drawable.icn_like_yes );
int h = image.getIntrinsicHeight();
int w = image.getIntrinsicWidth();
image.setBounds( 0, 0, w, h );
likeCountTv.setCompoundDrawables( image, null, null, null );
}
else{
Drawable image = getResources().getDrawable( R.drawable.icn_like_no );
int h = image.getIntrinsicHeight();
int w = image.getIntrinsicWidth();
image.setBounds( 0, 0, w, h );
likeCountTv.setCompoundDrawables( image, null, null, null );
}
}
});
}
private void favouriteOrDisFavouriteQuestion(){
}
@Override
public void onClick(View view) {
switch (view.getId()){
case R.id.tv_like_count:
likeOrDislikeThisQuestion();
break;
case R.id.tv_favourite_count:
break;
}
}
}
我第一次使用updateFavouriteAndLikeIcons()更新了图标。然后，当用户单击类似按钮时，我叫likeOrDislikeThisQuestion()。计数器正在更新，但可绘制状态未更新。有时变量isLikedByUser变为false。
如果问题已经被喜欢，那么likeCollection必须具有该Document。如果该文档不存在，则表示用户不喜欢或不喜欢它。
我的数据库架构就像
- likeCollection
userID (Document ID)
questionID = true // true for like and false for dislike..
答案 0 :(得分：1)
请勿在事务功能内部修改应用程序状态。这样做会引入并发问题，因为事务功能可以运行多次，并且不能保证在UI线程上运行。而是从事务功能中传递所需的信息。
这就是这里发生的情况，您必须在变量booleanTask的侦听器中运行每个应用程序修改。不要在事务的apply方法中更改类变量。