java - 回收站 View 中的重复项，notifydatasetchanged 不起作用

Question

我在单击适配器内的布局时运行事务，但是当我单击布局时，事务成功运行。但它在我的 RecyclerView 中创建了另一个项目。我在事务中尝试了 notifydatasetChanged() 但它会产生错误:

CalledFromWrongThreadException: Only the original thread that created a view 
hierarchy can touch its views.

然后我尝试将 notifyDataSetChanged() 放在事务之外，但它不起作用。以下是我正在做的事情:

holder.follow.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(final View view) {
                DatabaseReference mWorkDatabase = 
                FirebaseDatabase.getInstance().getReference()
               .child("WorkforWorkMen").child(work_id).child("follower");
                mWorkDatabase.runTransaction(new Transaction.Handler() {
                    @Override
                    public Transaction.Result doTransaction(MutableData 
                     mutableData) {
                        if(holder.followText.getText().equals("Follow")) {
                            holder.followText.setText("Following");
                            FirebaseAuth mAuth = FirebaseAuth.getInstance();
                            String current_user = 
                            mAuth.getCurrentUser().getUid();
                            DatabaseReference mFollowingDatabase = 
                            FirebaseDatabase.getInstance().getReference()
                  .child("WorkFollowing").child(current_user).child(work_id);
                            final Map fol = new HashMap();
                            fol.put("follower",work_id);
                            mFollowingDatabase.setValue(fol);
                            mutableData.setValue
                  (Integer.parseInt(mutableData.getValue().toString()) + 1);
                        }

                    else {
                            holder.followText.setText("Follow");
                            FirebaseAuth mAuth = FirebaseAuth.getInstance();
                            String current_user = 
                            mAuth.getCurrentUser().getUid();
                            DatabaseReference mFollowingDatabase = 
                            FirebaseDatabase.getInstance().getReference()
                  .child("WorkFollowing").child(current_user).child(work_id);
                            mFollowingDatabase.setValue(null);
                            mutableData.setValue(Integer
                           .parseInt(mutableData.getValue().toString()) - 1);
                        }

                        return Transaction.success(mutableData);
                    }
                    @Override
                    public void onComplete(DatabaseError databaseError, 
                    boolean b, DataSnapshot dataSnapshot) {
                        Toast.makeText(context,"error on complete"+ 
                  String.valueOf(databaseError), Toast.LENGTH_SHORT).show();
                        Log.i("eror here", "onComplete: 
                  "+String.valueOf(databaseError));
                    }
                });
                new Handler(Looper.getMainLooper()).post(new Runnable() {
                    @Override
                    public void run() {
                        Toast.makeText(context, "here", 
                          Toast.LENGTH_SHORT).show();
                        notifyDataSetChanged();
                    }
                });

            }
        });

我想当我将数据添加到我的列表时，关注者值(value)的变化会导致它添加一个新项目，但我不确定

 private void loadMessages(){
    if(keys.size() == 0){
        messagesList.clear(); 
        Toast.makeText(getContext(), " size zero no results found", 
    Toast.LENGTH_SHORT).show();
    }
    else {
        messagesList.clear();
        for (int i = 0; i < 5; i++) {
            if (i>=keys.size()){
                Toast.makeText(getContext(), "list is less than 5 item", 
            Toast.LENGTH_SHORT).show();
            }
            else {
                listPos = i;
                String id = keys.get(i);
                mWorkDatabase.child(id).addValueEventListener(new ValueEventListener() {
                    @Override
                    public void onDataChange(DataSnapshot dataSnapshot) {
                        String messageKey = dataSnapshot.getKey();
                        NewWork message = dataSnapshot.getValue(NewWork.class);
                        itemPos++;
                        messagesList.add(message);
                        mAdapter.notifyDataSetChanged();
                        mRecyclerView2.scrollToPosition(messagesList.size() - 1);
                    }
                    @Override
                    public void onCancelled(DatabaseError databaseError) {
                    }
                });
            }
        }
    }
}

Answer 1

您正在从后台线程调用notifyDataSetChanged()，您需要从ui线程调用它，如下所示

new Handler(Looper.getMainLooper()).post(new Runnable() {
            @Override
            public void run() {

                notifyDataSetChanged();
            }
        });