java - 调用 adapter.notifyItemChanged(position); 工作很奇怪
问题描述
我有一个从 firebase 获得的列表，这个列表是关于帖子的，我需要的是当用户喜欢或不喜欢它时，通过适配器更新列表。因为我使用 recyclerview 和适配器在从 firebase 接收数据后显示我的数据。实际上，一切对我来说都很好，但是当用户喜欢或不喜欢帖子时，这个问题就会变得疯狂。我试着祝酒以确保我的工作与我预期的相同，这证明我是对的。
帖子的照片通过点击视频显示的“喜欢”按钮出现和消失，并且它没有以正确的方式更新数据，就像它与喜欢的数量一样
您可以在下面通过视频找到我的代码，以说明我面临的问题。
我希望有人可以帮助我。
private void read_posts() {
DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Posts");
reference.addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
//post_models.clear();
Post_Model post_model = dataSnapshot.getValue(Post_Model.class);
post_models.add(post_model);
post_adapter = new Post_Adapter(post_models, getContext());
recyclerviewNewsfeed.setAdapter(post_adapter);
progressBar.setVisibility(View.GONE);
}
@Override
public void onChildChanged(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
Post_Model post_model = dataSnapshot.getValue(Post_Model.class);
for (int i=0;i<post_models.size();i++){
if(post_models.get(i).getId().equals(post_model.getId())){
post_models.set(i,post_model);
post_adapter.notifyItemChanged(i);
break;
}
}
}
@Override
public void onChildRemoved(@NonNull DataSnapshot dataSnapshot) {
}
@Override
public void onChildMoved(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
}
这是我的帖子适配器
public class Post_Adapter extends RecyclerView.Adapter<Post_Adapter.Viewholder> {
private Context context;
private List<Post_Model> post_models;
FirebaseUser firebaseUser;
List<Like_Model> like_modelList, likeblue_modelList;
View_Photos_Adapter view_Photos_adapter;
boolean userlikeit;
public static int positionn=-1;
public Post_Adapter(List<Post_Model> post_models, Context context) {
this.context = context;
this.post_models = post_models;
}
@NonNull
@Override
public Viewholder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.post_item, parent, false);
return new Viewholder(view);
}
@SuppressLint("SetTextI18n")
@Override
public void onBindViewHolder(@NonNull final Viewholder holder, final int position) {
final Post_Model post_model = post_models.get(position);
firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
DatabaseReference referencee = FirebaseDatabase.getInstance().getReference("Posts").child(post_model.getId());
referencee.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
//Toast.makeText(CommentActivity.this, post_id+"", Toast.LENGTH_SHORT).show();
Post_Model post_modell = dataSnapshot.getValue(Post_Model.class);
// Toast.makeText(CommentActivity.this, post_id+"", Toast.LENGTH_SHORT).show();
if (post_modell.getLikeModels() != null) {
for (int i = 0; i < post_modell.getLikeModels().size(); i++) {
if (post_modell.getLikeModels().get(i).getUserid().equals(firebaseUser.getUid())) {
userlikeit = true;
break;
} else {
userlikeit = false;
}
}
} else {
userlikeit = false;
}
//snapshot.getRef().removeValue();
// Toast.makeText(context, userlikeit+"58", Toast.LENGTH_SHORT).show();
//Toast.makeText(CommentActivity.this, comment_models.size()+"", Toast.LENGTH_SHORT).show();
if (userlikeit) {
holder.likebluebtn.setVisibility(View.VISIBLE);
holder.likebtn.setVisibility(View.GONE);
} else {
holder.likebtn.setVisibility(View.VISIBLE);
holder.likebluebtn.setVisibility(View.GONE);
}
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
if (post_model.getUserid().equals(firebaseUser.getUid())) {
holder.editbtn.setVisibility(View.VISIBLE);
holder.deletebtn.setVisibility(View.VISIBLE);
} else {
holder.editbtn.setVisibility(View.GONE);
holder.deletebtn.setVisibility(View.GONE);
}
holder.editbtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
holder.postTextView.setVisibility(View.GONE);
holder.postEditText.setVisibility(View.VISIBLE);
holder.postEditText.setText(post_model.getPost());
holder.editbtn.setVisibility(View.GONE);
holder.savebtn.setVisibility(View.VISIBLE);
}
});
holder.savebtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Post_Model post_modell = new Post_Model(post_model.getId(), post_model.getUserid()
, holder.postEditText.getText().toString(), post_model.getTime()
, post_model.getCommentModels(), post_model.getPostphotos(), post_model.getLikeModels());
FirebaseDatabase.getInstance().getReference("Posts")
.child(post_model.getId())
.setValue(post_modell);
holder.postTextView.setVisibility(View.VISIBLE);
holder.postEditText.setVisibility(View.GONE);
holder.editbtn.setVisibility(View.VISIBLE);
holder.savebtn.setVisibility(View.GONE);
Toast.makeText(context, "Post has been edited successfully", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(context, NewsfeedActivity.class);
context.startActivity(intent);
((Activity) context).overridePendingTransition(R.anim.slide_in_right, R.anim.slide_in_left);
((Activity) context).finish();
}
});
holder.deletebtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
new AlertDialog.Builder(context)
.setTitle("Delete Post")
.setMessage("Are you sure you want to delete this post?")
// Specifying a listener allows you to take an action before dismissing the dialog.
// The dialog is automatically dismissed when a dialog button is clicked.
.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
final DatabaseReference referencee = FirebaseDatabase.getInstance().getReference("Posts")
.child(post_model.getId());
referencee.removeValue();
Toast.makeText(context, "Post deleted successfully", Toast.LENGTH_LONG).show();
Intent intent = new Intent(context, NewsfeedActivity.class);
context.startActivity(intent);
((Activity) context).overridePendingTransition(R.anim.slide_in_right, R.anim.slide_in_left);
((Activity) context).finish();
}
})
// A null listener allows the button to dismiss the dialog and take no further action.
.setNegativeButton(android.R.string.no, null)
.setIcon(android.R.drawable.ic_dialog_alert)
.show();
}
});
firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
like_modelList = new ArrayList<>();
likeblue_modelList = new ArrayList<>();
//Toast.makeText(context, read_likes(post_model.getId())+"", Toast.LENGTH_SHORT).show();
DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Users");
reference.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
User user = snapshot.getValue(User.class);
// Toast.makeText(Create_Coworking_SpaceActivity.this, "111111111", Toast.LENGTH_LONG).show();
if (user.getId().equals(post_model.getUserid())) {
if (user.getImageURL().equals("default")) {
holder.userImage.setImageResource(R.drawable.ic_imgprofile);
} else {
Glide.with(holder.itemView).load(user.getImageURL()).into( holder.userImage);
}
holder.username.setText(user.getUsername());
}
}
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
if (post_model.getPostphotos() == null) {
holder.postPhotosRC.setVisibility(View.GONE);
} else {
holder.postPhotosRC.setHasFixedSize(true);
holder.postPhotosRC.setLayoutManager(new LinearLayoutManager(context, LinearLayoutManager.HORIZONTAL, false));
view_Photos_adapter = new View_Photos_Adapter(post_model.getPostphotos(), context);
holder.postPhotosRC.setAdapter(view_Photos_adapter);
}
holder.postTextView.setText(post_model.getPost());
holder.posttimeTextView.setText(post_model.getTime());
holder.commentbtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(context, CommentActivity.class);
intent.putExtra("post_id", post_model.getId());
context.startActivity(intent);
((Activity) context).overridePendingTransition(R.anim.slide_in_right, R.anim.slide_in_left);
}
});
if (post_model.getCommentModels() != null) {
holder.numofcommentsEditText.setText(post_model.getCommentModels().size() + "");
holder.numofcommentsTextView.setText(post_model.getCommentModels().size() + "");
}
final int[] li = {0};
holder.likebtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
like(post_model.getId());
// Post_Adapter.this.notifyItemChanged(position);
positionn=position;
}
});
holder.likebluebtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//Toast.makeText(context, userlikeit+"5", Toast.LENGTH_SHORT).show();
unlike(post_model.getId());
// Post_Adapter.this.notifyItemChanged(position);
positionn=position;
}
});
if (post_model.getLikeModels() != null) {
holder.numoflikesEditText.setText(post_model.getLikeModels().size() + "");
holder.numoflikesTextView.setText(post_model.getLikeModels().size() + "");
}
holder.likesTextView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(context, LikeActivity.class);
intent.putExtra("post_id", post_model.getId());
context.startActivity(intent);
((Activity) context).overridePendingTransition(R.anim.slide_in_right, R.anim.slide_in_left);
}
});
holder.commentsTextView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(context, CommentActivity.class);
intent.putExtra("post_id", post_model.getId());
context.startActivity(intent);
((Activity)
context).overridePendingTransition(R.anim.slide_in_right,
R.anim.slide_in_left);
}
});
}
@Override
public int getItemCount() {
return post_models == null ? 0 : post_models.size();
}
解决方案
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