Android studio 人机聊天界面实现代码

首先，你需要先创建一个布局文件，用来显示聊天记录和输入框。可以参考以下代码：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ListView
        android:id="@+id/chat_listview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:divider="@null"
        android:dividerHeight="0dp"
        android:listSelector="@android:color/transparent"
        android:stackFromBottom="true" />

    <LinearLayout
        android:id="@+id/input_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="@android:color/white"
        android:orientation="horizontal"
        android:padding="@dimen/padding_medium">

        <EditText
            android:id="@+id/input_edittext"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:background="@android:color/transparent"
            android:hint="@string/enter_message"
            android:imeOptions="actionSend"
            android:inputType="text"
            android:maxLines="6"
            android:textColor="@android:color/black"
            android:textColorHint="@android:color/darker_gray"
            android:textSize="@dimen/font_medium" />

        <Button
            android:id="@+id/send_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/button_send"
            android:text="@string/send"
            android:textColor="@android:color/white"
            android:textSize="@dimen/font_medium" />

    </LinearLayout>

</RelativeLayout>

然后，在Activity中，你需要实现一个适配器来展示聊天记录，并且监听发送按钮的点击事件，将输入框中的文本发送给对方。可以参考以下代码：

public class ChatActivity extends AppCompatActivity implements View.OnClickListener {

    private ListView mChatListView;
    private EditText mInputEditText;
    private Button mSendButton;

    private List<Message> mMessageList;
    private ChatAdapter mAdapter;

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

        mChatListView = findViewById(R.id.chat_listview);
        mInputEditText = findViewById(R.id.input_edittext);
        mSendButton = findViewById(R.id.send_button);
        mSendButton.setOnClickListener(this);

        mMessageList = new ArrayList<>();
        mAdapter = new ChatAdapter(this, mMessageList);
        mChatListView.setAdapter(mAdapter);
    }

    @Override
    public void onClick(View v) {
        if (v == mSendButton) {
            String messageText = mInputEditText.getText().toString().trim();
            if (!TextUtils.isEmpty(messageText)) {
                Message message = new Message(messageText, true);
                mMessageList.add(message);
                mAdapter.notifyDataSetChanged();
                mInputEditText.setText("");
            }
        }
    }
}

其中，Message是一个简单的数据类，用来保存聊天记录的文本和发送者的信息。ChatAdapter则是一个继承自BaseAdapter的适配器，用来将数据绑定到ListView上。具体实现可以参考以下代码：

public class ChatAdapter extends BaseAdapter {

    private Context mContext;
    private List<Message> mMessageList;

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

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

    @Override
    public Message getItem(int position) {
        return mMessageList.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public int getItemViewType(int position) {
        return getItem(position).isSentByMe() ? 0 : 1;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder;
        if (convertView == null) {
            int layoutId = getItemViewType(position) == 0 ?
                    R.layout.list_item_chat_sent : R.layout.list_item_chat_received;
            convertView = LayoutInflater.from(mContext).inflate(layoutId, parent, false);
            viewHolder = new ViewHolder(convertView);
            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }
        viewHolder.bindView(getItem(position));
        return convertView;
    }

    private static class ViewHolder {
        private TextView mMessageTextView;

        ViewHolder(View itemView) {
            mMessageTextView = itemView.findViewById(R.id.message_textview);
        }

        void bindView(Message message) {
            mMessageTextView.setText(message.getText());
        }
    }
}

最后，你还需要定义两个布局文件，分别用来显示发送和接收到的消息。可以参考以下代码：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="@dimen/padding_small">

    <TextView
        android:id="@+id/message_textview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/chat_bubble_sent"
        android:padding="@dimen/padding_medium"
        android:textColor="@android:color/white"
        android:textSize="@dimen/font_medium" />

</RelativeLayout>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="@dimen/padding_small">

    <TextView
        android:id="@+id/message_textview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/chat_bubble_received"
        android:padding="@dimen/padding_medium"
        android:textColor="@android:color/black"
        android:textSize="@dimen/font_medium" />

</RelativeLayout>

注意，这里使用了不同的背景图片来区分发送和接收到的消息。

至此，你就完成了一个简单的人机聊天界面的实现。