问Android Studio Constraintlayout编程靠右对齐

EN

public class MessageListAdapter extends RecyclerView.Adapter {
private static final int VIEW_TYPE_MESSAGE_SENT = 1;
private static final int VIEW_TYPE_MESSAGE_RECEIVED = 2;

private Context mContext;
private List<UserMessage> mMessageList;

public MessageListAdapter(Context context, List<UserMessage> messageList) {
    mContext = context;
    mMessageList = messageList;
}

@Override
public int getItemCount() {
    return mMessageList.size();
}

// Determines the appropriate ViewType according to the sender of the message.
@Override
public int getItemViewType(int position) {
    UserMessage message = (UserMessage) mMessageList.get(position);

    if (message.getSender().getUserId().equals(currentUserId)) {
        // If the current user is the sender of the message
        return VIEW_TYPE_MESSAGE_SENT;
    } else {
        // If some other user sent the message
        return VIEW_TYPE_MESSAGE_RECEIVED;
    }
}

// Inflates the appropriate layout according to the ViewType
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view;

    if (viewType == VIEW_TYPE_MESSAGE_SENT) {
        view = LayoutInflater.from(parent.getContext())
        .inflate(R.layout.item_message_sent, parent, false);
        return new SentMessageHolder(view);
    } else if (viewType == VIEW_TYPE_MESSAGE_RECEIVED) {
        view = LayoutInflater.from(parent.getContext())
        .inflate(R.layout.item_message_received, parent, false);
        return new ReceivedMessageHolder(view);
    }

    return null;
}

// Passes the message object to a ViewHolder so that the contents can be bound to UI.
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
    UserMessage message = (UserMessage) mMessageList.get(position);

    switch (holder.getItemViewType()) {
        case VIEW_TYPE_MESSAGE_SENT:
          ((SentMessageHolder) holder).bind(message);
          break;
        case VIEW_TYPE_MESSAGE_RECEIVED:
          ((ReceivedMessageHolder) holder).bind(message);
    }
}

private class SentMessageHolder extends RecyclerView.ViewHolder {

    SentMessageHolder(View itemView) {
        super(itemView);

        //bind views
    }

    void bind(UserMessage message) {
        //set values
    }
}

private class ReceivedMessageHolder extends RecyclerView.ViewHolder {

    ReceivedMessageHolder(View itemView) {
        super(itemView);

        //bind views
    }

    void bind(UserMessage message) {
        //set values
    }
}
}