Question

我有一个聊天应用程序的方法，一切似乎都正常运行，但是每次我尝试键入内容时，都不会弹出。

用户登录时，onActivityResult显示成功消息：

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == SIGN_IN_REQUEST_CODE) {
        if (resultCode == RESULT_OK) {
            Snackbar.make(activity_main, "Success. Welcome.", Snackbar.LENGTH_SHORT).show();
        }
        else {
            Snackbar.make(activity_main, "Error", Snackbar.LENGTH_SHORT).show();
            finish();
        }
    }
}

但是，在以下情况下，它不会显示我的onCreate欢迎消息：

if(FirebaseAuth.getInstance().getCurrentUser() == null) {
    startActivityForResult(AuthUI.getInstance().createSignInIntentBuilder().build(), SIGN_IN_REQUEST_CODE);
}
else {
    Snackbar.make(activity_main, "Welcome " + FirebaseAuth.getInstance().getCurrentUser().getEmail(), Snackbar.LENGTH_SHORT);
    //Load content
    displayChat();
}

键入消息时，也不会显示任何内容。我查询不正确吗？

private void displayChat() {

    ListView listOfMessage = findViewById(R.id.list_of_message);

    Query query = FirebaseDatabase.getInstance().getReference();
    FirebaseListOptions<Chat> options = new FirebaseListOptions.Builder<Chat>()
            .setLayout(R.layout.list_item)
            .setQuery(query, Chat.class)
            .build();

    adapter = new FirebaseListAdapter<Chat>(options) {
        @Override
        protected void populateView(View v, Chat model, int position) {
            //Get reference to the views of list_item.xml
            TextView messageText, messageUser, messageTime;
            messageText = v.findViewById(R.id.message_text);
            messageUser = v.findViewById(R.id.message_user);
            messageTime = v.findViewById(R.id.message_time);

            messageText.setText(model.getMessageText());
            messageUser.setText(model.getMessageUser());
            messageTime.setText(DateFormat.format("dd-MM-yyyy (HH:mm:ss)", model.getMessageTime()));
        }
    };
    listOfMessage.setAdapter(adapter);
}

我的数据库似乎正常，输入没有错误：

{
  "rules": {
    ".read": true,
    ".write": true
  }
}

Answer 1

您需要获取数据库的参考，然后对其进行查询：

final DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference();

根据您的要求查询类似的内容：-

Query query = reference.child("Chat_room");
query.addListenerForSingleValueEvent(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        if (dataSnapshot.exists()) {
            // dataSnapshot is the "chat_room" node with all children 
            for (DataSnapshot issue : dataSnapshot.getChildren()) {
                // do something with the individual "issues"
            }
        }
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {

    }
});

注意：-确保已创建数据库，将聊天消息保存到数据库的结构对于想要检索和显示聊天的方式很重要。

Firebase查询不显示聊天

1 个答案: