如何在Android聊天中的ListView中修复此错误

Question

I'm trying to do an Android Chat using ListView and Adapter and to test my code I'm using two TextView each with its send button, the fact is that it works OK when I sequentially first sent a message using the button1 and then the button2 and so on successively and in the Listview the messages are sequentially located, but if I sent several messages only using the button 1 or the button 2, this sequence is lost and the Listview is messed up, the variable myMessage is supposed to be in control but not is working, someone could tell me how I can correct this.

Here is MainActivity:

public class MainActivity extends AppCompatActivity {

private ListView listView;
private View btnSend;
private EditText editText;
boolean myMessage = true;
private List<ChatBubble> ChatBubbles;
private ArrayAdapter<ChatBubble> adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

ChatBubbles = new ArrayList<>();

listView = (ListView) findViewById(R.id.list_msg);
btnSend1 = findViewById(R.id.btn_chat_send1);
btnSend2 = findViewById(R.id.btn_chat_send2);
editText1 = (EditText) findViewById(R.id.msg_type1);
editText2 = (EditText) findViewById(R.id.msg_type2);

//set ListView adapter first
adapter = new MessageAdapter(this, R.layout.left_chat_bubble, ChatBubbles);
listView.setAdapter(adapter);

//event for button SEND1
btnSend1.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        if (editText1.getText().toString().trim().equals("")) {
            Toast.makeText(MainActivity.this, "Please input some text...", Toast.LENGTH_SHORT).show();
        } else {
            myMessage = true;
            ChatBubble ChatBubble = new ChatBubble(editText1.getText().toString(), myMessage);
            ChatBubbles.add(ChatBubble);
            adapter.notifyDataSetChanged();
            editText1.setText("");
        }
    }
});

//event for button SEND2
btnSend2.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        if (editText2.getText().toString().trim().equals("")) {
            Toast.makeText(MainActivity.this, "Please input some text...", Toast.LENGTH_SHORT).show();
        } else {
            myMessage = false;
            ChatBubble ChatBubble = new ChatBubble(editText2.getText().toString(), myMessage);
            ChatBubbles.add(ChatBubble);
            adapter.notifyDataSetChanged();
            editText2.setText("");
        }
      }
  });
 }
}

Here is the MessageAdapter class:

public class MessageAdapter extends ArrayAdapter<ChatBubble> {

private Activity activity;
private List<ChatBubble> messages;

public MessageAdapter(Activity context, int resource, List<ChatBubble> objects) {
    super(context, resource, objects);
    this.activity = context;
    this.messages = objects;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder holder;
    LayoutInflater inflater = (LayoutInflater) activity.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);

    int layoutResource = 0; // determined by view type
    ChatBubble ChatBubble = getItem(position);
    int viewType = getItemViewType(position);

    if (ChatBubble.myMessage()) {
        layoutResource = R.layout.left_chat_bubble;
    } else {
        layoutResource = R.layout.right_chat_bubble;
    }

    if (convertView != null) {
        holder = (ViewHolder) convertView.getTag();
    } else {
        convertView = inflater.inflate(layoutResource, parent, false);
        holder = new ViewHolder(convertView);
        convertView.setTag(holder);
    }

    //set message content
    holder.msg.setText(ChatBubble.getContent());

    return convertView;
}

@Override
public int getViewTypeCount() {
    // return the total number of view types. this value should never change
    // at runtime. Value 2 is returned because of left and right views.
    return 2;
}

@Override
public int getItemViewType(int position) {
    // return a value between 0 and (getViewTypeCount - 1)
    return position % 2;
}

private class ViewHolder {
    private TextView msg;

    public ViewHolder(View v) {
        msg = (TextView) v.findViewById(R.id.txt_msg);
    }
  }
}

And also ChatBubble class:

public class ChatBubble {

private String content;
private boolean myMessage;

public ChatBubble(String content, boolean myMessage) {
    this.content = content;
    this.myMessage = myMessage;
}

public String getContent() {
    return content;
}

public boolean myMessage() {
    return myMessage;
 }
}

Answer 1

Error #1: Variable type and the variable itself must not have the same name.

ChatBubble ChatBubble = new ChatBubble(...); // INCORRECT
ChatBubble chatBubble = new ChatBubble(...); // CORRECT

Answer 2

I think that ViewType is switched between even and odd. How about this code?

MessageAdapter

@Override
public int getItemViewType(int position) {
    ChatBubble chatBubble = messages.get(position);
    return chatBubble.myMessage() ? 1 : 0;
}