Question

我希望允许用户彼此发送消息。到目前为止，我已经设置了接收方和发送方的布局以及回收视图。当用户尝试向某人发送消息时，该消息将被发送并成功加载到回收视图中，但是接收者没有收到该消息，但是对于发送者来说确实会出现。我基本上尝试这样做的方式是，当用户选择要发送消息的人时，我将所选用户的UID存储为接收者，而发送者将是当前登录的用户。

//Loads data into views
    @Override
    public void onBindViewHolder(@NonNull MessageViewHolder viewHolder, int i) {

        //logged in user will be the sender of the message
        String senderOfMessage = mAuth.getCurrentUser().getUid();
        Message  message= userMessagesList.get(i);

        String  receiverOfMessage = message.getReceiver();



        if(receiverOfMessage.equals(senderOfMessage)){
            viewHolder.senderTextView.setVisibility(View.VISIBLE);
            viewHolder.senderTextView.setBackgroundResource(R.drawable.sender_messages_layout);
            viewHolder.senderTextView.setTextColor(Color.BLACK);
            viewHolder.senderTextView.setText(message.getMessage());

        }else{
            viewHolder.receiverTextView.setVisibility(View.VISIBLE);
            viewHolder.receiverTextView.setBackgroundResource(R.drawable.receiver_messages_layout);
            viewHolder.receiverTextView.setTextColor(Color.BLACK);
            viewHolder.receiverTextView.setText(message.getMessage());


        }







    }

这就是我保存邮件的方式

   //saves messages to firebase
    public void saveMessages() {
        //store data under timestamp to prevent overriding current information from Firebase...
        SimpleDateFormat formatter = new SimpleDateFormat(" HH:mm:ss ");
        Date date = new Date(System.currentTimeMillis());
        messageTimeStamp = currentFirebaseUser.getUid() + formatter.format(date);

        String messageSender = currentFirebaseUser.getUid();
        String messeaageReceiver = id;

        messageDictionary.put("message", messageInputEditText.getText().toString());
        messageDictionary.put("sender", currentFirebaseUser.getUid());
        messageDictionary.put("receiver", id);
        messesagesRef.child("Messages").child(messageSender).child(messeaageReceiver).push().setValue(messageDictionary);
        messageInputEditText.setText("");

    }

这就是我的检索方式

final String messageSender = currentFirebaseUser.getUid();
        final String messeaageReceiver = id;
        //cleared message b4 to prevent duplication...
        messageList.clear();

        firebaseDatabase.child("Messages").child(messageSender).child(messeaageReceiver).addChildEventListener(new ChildEventListener() {
            @Override
            public void onChildAdded(DataSnapshot dataSnapshot, String s) {
                messages = dataSnapshot.getValue(Message.class);
                messageList.add(messages);
                messageAdapter.notifyDataSetChanged();


            }

            @Override
            public void onChildChanged(DataSnapshot dataSnapshot, String s) {

            }

            @Override
            public void onChildRemoved(DataSnapshot dataSnapshot) {

            }

            @Override
            public void onChildMoved(DataSnapshot dataSnapshot, String s) {

            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });
    }

**数据库结构**

qnrE4PTKbNdKNs33cKtx1qLEvnS2
 C0EBxNAEmahhTEztCIu1yNg4wQz1
 -LpBiC7SRcHuoxzPAxN8
 message:  "Hi"
 receiver: "C0EBxNAEmahhTEztCIu1yNg4wQz1"
 sender:   "qnrE4PTKbNdKNs33cKtx1qLEvnS2"

Answer 1

也许您可以尝试实现Recycler视图的方法getItemViewType，并在那里使用您的概念定义布局类型。

getItemViewType返回视图类型的整数，因此您可以定义最终整数

public static final int RECEIVER = 1;
public static final int SENDER = 2;

现在使用概念检查项目视图类型

@Override
public int getItemViewType(int position) {
    String senderOfMessage = mAuth.getCurrentUser().getUid();
    Message  message= userMessagesList.get(position);

    String  receiverOfMessage = message.getReceiver();

    if(receiverOfMessage.equals(senderOfMessage)) 
        return [SENDER OR RECEIVER according to your condition]
    else
        return [SENDER OR RECEIVER according to your condition]

    return -1;
}

现在使用getItemViewType(i)作为onBindViewHolder中的第一条语句来显示各自的布局。

@Override
public void onBindViewHolder(@NonNull MessageViewHolder viewHolder, int i) {
    int itemViewType = getItemViewType(i);

    if(itemViewType == [RECEIVER or SENDER]){
        viewHolder.senderTextView.setVisibility(View.VISIBLE);
        viewHolder.senderTextView.setBackgroundResource(R.drawable.sender_messages_layout);
        viewHolder.senderTextView.setTextColor(Color.BLACK);
        viewHolder.senderTextView.setText(message.getMessage());

    } else{
        viewHolder.receiverTextView.setVisibility(View.VISIBLE);
        viewHolder.receiverTextView.setBackgroundResource(R.drawable.receiver_messages_layout);
        viewHolder.receiverTextView.setTextColor(Color.BLACK);
        viewHolder.receiverTextView.setText(message.getMessage());
    }
}

为什么所选用户没有收到他们的消息？

1 个答案: