Android RecyclerView设计与好友聊天列表代码

下面是一个简单的 Android RecyclerView 设计的好友聊天列表代码：

1. 在布局文件中添加 RecyclerView：

<androidx.recyclerview.widget.RecyclerView
    android:id="@+id/recycler_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:scrollbars="vertical"/>

2. 创建 RecyclerView 的 Adapter：

public class ChatListAdapter extends RecyclerView.Adapter<ChatListAdapter.ViewHolder> {

    private List<ChatMessage> chatMessages;

    public ChatListAdapter(List<ChatMessage> chatMessages) {
        this.chatMessages = chatMessages;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_chat_message, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        ChatMessage message = chatMessages.get(position);
        holder.bind(message);
    }

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

    public static class ViewHolder extends RecyclerView.ViewHolder {

        private TextView messageTextView;
        private TextView timeTextView;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            messageTextView = itemView.findViewById(R.id.message_text_view);
            timeTextView = itemView.findViewById(R.id.time_text_view);
        }

        public void bind(ChatMessage message) {
            messageTextView.setText(message.getMessage());
            timeTextView.setText(message.getTime());
        }
    }
}

3. 创建聊天消息的数据模型：

public class ChatMessage {
    private String message;
    private String time;

    public ChatMessage(String message, String time) {
        this.message = message;
        this.time = time;
    }

    public String getMessage() {
        return message;
    }

    public String getTime() {
        return time;
    }
}

4. 创建 RecyclerView 的 Item 布局文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="8dp"
    android:layout_marginTop="8dp"
    android:orientation="vertical">

    <TextView
        android:id="@+id/message_text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/bg_chat_message"
        android:padding="8dp"
        android:textColor="@android:color/primary_text_light"/>

    <TextView
        android:id="@+id/time_text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="4dp"
        android:textColor="@android:color/secondary_text_dark"/>

</LinearLayout>

5. 在 Activity 或 Fragment 中初始化 RecyclerView 和 Adapter：

public class ChatListActivity extends AppCompatActivity {

    private RecyclerView recyclerView;
    private ChatListAdapter adapter;

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

        List<ChatMessage> chatMessages = new ArrayList<>();
        chatMessages.add(new ChatMessage("Hello", "10:00 AM"));
        chatMessages.add(new ChatMessage("How are you?", "10:01 AM"));
        chatMessages.add(new ChatMessage("I'm fine, thank you. And you?", "10:02 AM"));
        chatMessages.add(new ChatMessage("I'm good too. Thanks for asking.", "10:03 AM"));

        recyclerView = findViewById(R.id.recycler_view);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        adapter = new ChatListAdapter(chatMessages);
        recyclerView.setAdapter(adapter);
    }
}

这样就完成了 RecyclerView 的设计和好友聊天列表的代码实现。