IVS 聊天功能客户端消息收发 SDK：Android 教程第 2 部分：消息和事件

本教程的第 2 部分（也是最后一部分）分为几个章节：

1. 为发送消息创建一个 UI

   1. UI 主布局

   2. UI 将文本单元格抽象化以便一致地显示文本

   3. UI 左侧聊天消息

   4. UI 右侧聊天消息

   5. UI 其他颜色值

2. 应用视图绑定

3. 管理聊天消息请求

4. 最终步骤

要学习完整的 SDK 文档，请从亚马逊 IVS 聊天功能客户端消息收发 SDK（在《Amazon IVS 聊天功能用户指南》中）和 Chat Client Messaging: SDK for Android Reference（在 GitHub 上）开始。

先决条件

确保您已完成本教程的第 1 部分聊天室。

为发送消息创建一个 UI

现在我们已成功初始化聊天室连接，接下来可以发送第一条消息了。要使用此功能，需要一个 UI。我们将添加：

• connect/disconnect 按钮

• 使用 send 按钮输入消息

• 动态消息列表。为了构建此内容，我们使用了 Android Jetpack RecyclerView。

UI 主布局

请参阅 Android 开发者文档中的 Android Jetpack 布局。

XML：

// ./app/src/main/res/layout/activity_main.xml


<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
                                                     xmlns:app="http://schemas.android.com/apk/res-auto"
                                                     xmlns:tools="http://schemas.android.com/tools"
                                                     android:layout_width="match_parent"
                                                     android:layout_height="match_parent">

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
                  xmlns:app="http://schemas.android.com/apk/res-auto"
                  android:id="@+id/connect_view"
                  android:layout_width="match_parent"
                  android:layout_height="match_parent"
                  android:gravity="center"
                  android:orientation="vertical">

        <androidx.cardview.widget.CardView
                android:id="@+id/connect_button"
                android:layout_width="match_parent"
                android:layout_height="48dp"
                android:layout_gravity=""
                android:layout_marginStart="16dp"
                android:layout_marginTop="4dp"
                android:layout_marginEnd="16dp"
                android:clickable="true"
                android:elevation="16dp"
                android:focusable="true"
                android:foreground="?android:attr/selectableItemBackground"
                app:cardBackgroundColor="@color/purple_500"
                app:cardCornerRadius="10dp">

            <TextView
                    android:id="@+id/connect_text"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_alignParentEnd="true"
                    android:layout_gravity="center"
                    android:layout_weight="1"
                    android:paddingHorizontal="12dp"
                    android:text="Connect"
                    android:textColor="@color/white"
                    android:textSize="16sp"/>

            <ProgressBar
                    android:id="@+id/activity_indicator"
                    android:layout_width="20dp"
                    android:layout_height="20dp"
                    android:layout_gravity="center"
                    android:layout_marginHorizontal="20dp"
                    android:indeterminateOnly="true"
                    android:indeterminateTint="@color/white"
                    android:indeterminateTintMode="src_atop"
                    android:keepScreenOn="true"
                    android:visibility="gone"/>
        </androidx.cardview.widget.CardView>

    </LinearLayout>

    <androidx.constraintlayout.widget.ConstraintLayout
            android:id="@+id/chat_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:clipToPadding="false"
            android:visibility="visible"
            tools:context=".MainActivity">

        <RelativeLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical"
                app:layout_constraintBottom_toTopOf="@+id/layout_message_input"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent">

            <androidx.recyclerview.widget.RecyclerView
                    android:id="@+id/recycler_view"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:clipToPadding="false"
                    android:paddingTop="70dp"
                    android:paddingBottom="20dp"/>
        </RelativeLayout>

        <RelativeLayout
                android:id="@+id/layout_message_input"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@android:color/white"
                android:clipToPadding="false"
                android:drawableTop="@android:color/black"
                android:elevation="18dp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintStart_toStartOf="parent">

            <EditText
                    android:id="@+id/message_edit_text"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_centerVertical="true"
                    android:layout_marginStart="16dp"
                    android:layout_toStartOf="@+id/send_button"
                    android:background="@android:color/transparent"
                    android:hint="Enter Message"
                    android:inputType="text"
                    android:maxLines="6"
                    tools:ignore="Autofill"/>

            <Button
                    android:id="@+id/send_button"
                    android:layout_width="84dp"
                    android:layout_height="48dp"
                    android:layout_alignParentEnd="true"
                    android:background="@color/black"
                    android:foreground="?android:attr/selectableItemBackground"
                    android:text="Send"
                    android:textColor="@color/white"
                    android:textSize="12dp"/>
        </RelativeLayout>
    </androidx.constraintlayout.widget.ConstraintLayout>


</androidx.coordinatorlayout.widget.CoordinatorLayout>

UI 将文本单元格抽象化以便一致地显示文本

XML：

// ./app/src/main/res/layout/common_cell.xml
   
<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:id="@+id/layout_container"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:background="@color/light_gray"
              android:minWidth="100dp"
              android:orientation="vertical">

    <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="horizontal">

        <TextView
                android:id="@+id/card_message_me_text_view"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_marginBottom="8dp"
                android:maxWidth="260dp"
                android:paddingLeft="12dp"
                android:paddingTop="8dp"
                android:paddingRight="12dp"
                android:text="This is a Message"
                android:textColor="#ffffff"
                android:textSize="16sp"/>

        <TextView
                android:id="@+id/failed_mark"
                android:layout_width="40dp"
                android:layout_height="match_parent"
                android:paddingRight="5dp"
                android:src="@drawable/ic_launcher_background"
                android:text="!"
                android:textAlignment="viewEnd"
                android:textColor="@color/white"
                android:textSize="25dp"
                android:visibility="gone"/>
    </LinearLayout>

</LinearLayout>

UI 左侧聊天消息

XML：

// ./app/src/main/res/layout/card_view_left.xml
 
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              xmlns:app="http://schemas.android.com/apk/res-auto"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_marginStart="8dp"
              android:layout_marginBottom="12dp"
              android:orientation="vertical">

    <TextView
            android:id="@+id/username_edit_text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="UserName"/>

    <androidx.constraintlayout.widget.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

        <androidx.cardview.widget.CardView
                android:id="@+id/card_message_other"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="left"
                android:layout_marginBottom="4dp"
                android:foreground="?android:attr/selectableItemBackground"
                app:cardBackgroundColor="@color/light_gray_2"
                app:cardCornerRadius="10dp"
                app:cardElevation="0dp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintStart_toStartOf="parent">

            <include layout="@layout/common_cell"/>
        </androidx.cardview.widget.CardView>

        <TextView
                android:id="@+id/dateText"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="4dp"
                android:layout_marginBottom="4dp"
                android:text="10:00"
                app:layout_constraintBottom_toBottomOf="@+id/card_message_other"
                app:layout_constraintLeft_toRightOf="@+id/card_message_other"/>
    </androidx.constraintlayout.widget.ConstraintLayout>


</LinearLayout>

UI 右侧聊天消息

XML：

// ./app/src/main/res/layout/card_view_right.xml
 
<?xml version="1.0" encoding="utf-8"?>

<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"                                                   xmlns:app="http://schemas.android.com/apk/res-auto"                                                   android:layout_width="match_parent"                                                   android:layout_height="wrap_content" 
android:layout_marginEnd="8dp">

    <androidx.cardview.widget.CardView
            android:id="@+id/card_message_me"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="right"
            android:layout_marginBottom="10dp"
            android:foreground="?android:attr/selectableItemBackground"
            app:cardBackgroundColor="@color/purple_500"
            app:cardCornerRadius="10dp"
            app:cardElevation="0dp"
            app:cardPreventCornerOverlap="false"
            app:cardUseCompatPadding="true"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent">

        <include layout="@layout/common_cell"/>

    </androidx.cardview.widget.CardView>

    <TextView
            android:id="@+id/dateText"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginRight="12dp"
            android:layout_marginBottom="4dp"
            android:text="10:00"
            app:layout_constraintBottom_toBottomOf="@+id/card_message_me"
            app:layout_constraintRight_toLeftOf="@+id/card_message_me"/>

</androidx.constraintlayout.widget.ConstraintLayout>

UI 其他颜色值

XML：

// ./app/src/main/res/values/colors.xml
 
<?xml version="1.0" encoding="utf-8"?>
<resources>
    <!--    ...-->
    <color name="dark_gray">#4F4F4F</color>
    <color name="blue">#186ED3</color>
    <color name="dark_red">#b30000</color>
    <color name="light_gray">#B7B7B7</color>
    <color name="light_gray_2">#eef1f6</color>
</resources>

应用视图绑定

我们利用 Android 视图绑定功能来引用 XML 布局的绑定类。要启用该功能，请在 ./app/build.gradle 中将 viewBinding 构建选项设置为 true：

Kotlin 脚本：

 // ./app/build.gradle

android {
//    ...

    buildFeatures {
        viewBinding = true
    }
//    ...
}

现在可以将 UI 与我们的 Kotlin 代码连接起来：

Kotlin：

// ./app/src/main/java/com/chatterbox/myapp/MainActivity.kt
package com.chatterbox.myapp
// ...
const val TAG = "Chatterbox-MyApp"


class MainActivity : AppCompatActivity() {
//    ...

    private fun sendMessage(request: SendMessageRequest) {
        try {
            room?.sendMessage(
                request,
                object : SendMessageCallback {
                    override fun onRejected(request: SendMessageRequest, error: ChatError) {
                        runOnUiThread {
                            entries.addFailedRequest(request)
                            scrollToBottom()
                            Log.e(TAG, "Message rejected: ${error.errorMessage}")
                        }
                    }
                }
            )

            entries.addPendingRequest(request)

            binding.messageEditText.text.clear()
            scrollToBottom()
        } catch (error: Exception) {
            Log.e(TAG, error.message ?: "Unknown error occurred")
        }
    }

    private fun scrollToBottom() {
        binding.recyclerView.smoothScrollToPosition(entries.size - 1)
    }

    private fun sendButtonClick(view: View) {
        val content = binding.messageEditText.text.toString()
        if (content.trim().isEmpty()) {
            return
        }

        val request = SendMessageRequest(content)
        sendMessage(request)
    }
}

我们还添加了删除消息和断开用户聊天连接的方法，可以使用聊天消息上下文菜单调用这些方法：

Kotlin：

// ./app/src/main/java/com/chatterbox/myapp/MainActivity.kt

package com.chatterbox.myapp
//    ...

class MainActivity : AppCompatActivity() {
//    ...

    private fun deleteMessage(request: DeleteMessageRequest) {
        room?.deleteMessage(
            request,
            object : DeleteMessageCallback {
                override fun onRejected(request: DeleteMessageRequest, error: ChatError) {
                    runOnUiThread {
                        Log.d(TAG, "Delete message rejected: ${error.errorMessage}")
                    }
                }
            }
        )
    }

    private fun disconnectUser(request: DisconnectUserRequest) {
        room?.disconnectUser(
            request,
            object : DisconnectUserCallback {
                override fun onRejected(request: DisconnectUserRequest, error: ChatError) {
                    runOnUiThread {
                        Log.d(TAG, "Disconnect user rejected: ${error.errorMessage}")
                    }
                }
            }
        )
    }
}

管理聊天消息请求

我们需要一种用于管理不同状态的聊天消息请求的方法：

• 待处理 — 消息已发送到聊天室，但尚未被确认或拒绝。

• 已确认 — 消息已被聊天室发送给所有用户（包括我们）。

• 已拒绝 — 消息已被聊天室拒绝，并提示带有错误对象。

我们会把未解决的聊天请求和聊天消息保留在列表中。该列表属于一个单独的类，我们称之为 ChatEntries.kt：

Kotlin：

// ./app/src/main/java/com/chatterbox/myapp/ChatEntries.kt

package com.chatterbox.myapp

import com.amazonaws.ivs.chat.messaging.entities.ChatMessage
import com.amazonaws.ivs.chat.messaging.requests.SendMessageRequest

sealed class ChatEntry() {
    class Message(val message: ChatMessage) : ChatEntry()
    class PendingRequest(val request: SendMessageRequest) : ChatEntry()
    class FailedRequest(val request: SendMessageRequest) : ChatEntry()
}

class ChatEntries {
    /* This list is kept in sorted order. ChatMessages are sorted by date, while pending and failed requests are kept in their original insertion point. */
    val entries = mutableListOf<ChatEntry>()
    var adapter: ChatListAdapter? = null

    val size get() = entries.size

    /**
     * Insert pending request at the end.
     */
    fun addPendingRequest(request: SendMessageRequest) {
        val insertIndex = entries.size
        entries.add(insertIndex, ChatEntry.PendingRequest(request))
        adapter?.notifyItemInserted(insertIndex)
    }

    /**
     * Insert received message at proper place based on sendTime. This can cause removal of pending requests.
     */
    fun addReceivedMessage(message: ChatMessage) {
        /* Skip if we have already handled that message. */
        val existingIndex = entries.indexOfLast { it is ChatEntry.Message && it.message.id == message.id }
        if (existingIndex != -1) {
            return
        }

        val removeIndex = entries.indexOfLast {
            it is ChatEntry.PendingRequest && it.request.requestId == message.requestId
        }
        if (removeIndex != -1) {
            entries.removeAt(removeIndex)
        }

        val insertIndexRaw = entries.indexOfFirst { it is ChatEntry.Message && it.message.sendTime > message.sendTime }
        val insertIndex = if (insertIndexRaw == -1) entries.size else insertIndexRaw
        entries.add(insertIndex, ChatEntry.Message(message))

        if (removeIndex == -1) {
            adapter?.notifyItemInserted(insertIndex)
        } else if (removeIndex == insertIndex) {
            adapter?.notifyItemChanged(insertIndex)
        } else {
            adapter?.notifyItemRemoved(removeIndex)
            adapter?.notifyItemInserted(insertIndex)
        }
    }

    fun addFailedRequest(request: SendMessageRequest) {
        val removeIndex = entries.indexOfLast {
            it is ChatEntry.PendingRequest && it.request.requestId == request.requestId
        }
        if (removeIndex != -1) {
            entries.removeAt(removeIndex)
            entries.add(removeIndex, ChatEntry.FailedRequest(request))
            adapter?.notifyItemChanged(removeIndex)
        } else {
            val insertIndex = entries.size
            entries.add(insertIndex, ChatEntry.FailedRequest(request))
            adapter?.notifyItemInserted(insertIndex)
        }
    }

    fun removeMessage(messageId: String) {
        val removeIndex = entries.indexOfFirst { it is ChatEntry.Message && it.message.id == messageId }
        entries.removeAt(removeIndex)
        adapter?.notifyItemRemoved(removeIndex)
    }

    fun removeFailedRequest(requestId: String) {
        val removeIndex = entries.indexOfFirst { it is ChatEntry.FailedRequest && it.request.requestId == requestId }
        entries.removeAt(removeIndex)
        adapter?.notifyItemRemoved(removeIndex)
    }

    fun removeAll() {
        entries.clear()
    }
}

为了将列表与 UI 连接起来，我们使用适配器。有关更多信息，请参阅使用 AdapterView 绑定到数据和生成的绑定类。

Kotlin：

// ./app/src/main/java/com/chatterbox/myapp/ChatListAdapter.kt

package com.chatterbox.myapp

import android.content.Context
import android.graphics.Color
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.LinearLayout
import android.widget.TextView
import androidx.core.content.ContextCompat
import androidx.core.view.isGone
import androidx.recyclerview.widget.RecyclerView
import com.amazonaws.ivs.chat.messaging.requests.DisconnectUserRequest
import java.text.DateFormat


class ChatListAdapter(
    private val entries: ChatEntries,
    private val onDisconnectUser: (request: DisconnectUserRequest) -> Unit,
) :
    RecyclerView.Adapter<ChatListAdapter.ViewHolder>() {
    var context: Context? = null
    var userId: String? = null

    class ViewHolder(view: View) : RecyclerView.ViewHolder(view) {
        val container: LinearLayout = view.findViewById(R.id.layout_container)
        val textView: TextView = view.findViewById(R.id.card_message_me_text_view)
        val failedMark: TextView = view.findViewById(R.id.failed_mark)
        val userNameText: TextView? = view.findViewById(R.id.username_edit_text)
        val dateText: TextView? = view.findViewById(R.id.dateText)
    }

    override fun onCreateViewHolder(viewGroup: ViewGroup, viewType: Int): ViewHolder {
        if (viewType == 0) {
            val rightView = LayoutInflater.from(viewGroup.context).inflate(R.layout.card_view_right, viewGroup, false)
            return ViewHolder(rightView)
        }
        val leftView = LayoutInflater.from(viewGroup.context).inflate(R.layout.card_view_left, viewGroup, false)
        return ViewHolder(leftView)
    }

    override fun getItemViewType(position: Int): Int {
        // Int 0 indicates to my message while Int 1 to other message
        val chatMessage = entries.entries[position]
        return if (chatMessage is ChatEntry.Message && chatMessage.message.sender.userId != userId) 1 else 0
    }

    override fun onBindViewHolder(viewHolder: ViewHolder, position: Int) {
        return when (val entry = entries.entries[position]) {
            is ChatEntry.Message -> {
                viewHolder.textView.text = entry.message.content

                val bgColor = if (entry.message.sender.userId == userId) {
                    R.color.purple_500
                } else {
                    R.color.light_gray_2
                }
                viewHolder.container.setBackgroundColor(ContextCompat.getColor(context!!, bgColor))

                if (entry.message.sender.userId != userId) {
                    viewHolder.textView.setTextColor(Color.parseColor("#000000"))
                }

                viewHolder.failedMark.isGone = true

                viewHolder.itemView.setOnCreateContextMenuListener { menu, _, _ ->
                    menu.add("Kick out").setOnMenuItemClickListener {
                        val request = DisconnectUserRequest(entry.message.sender.userId, "Some reason")
                        onDisconnectUser(request)
                        true
                    }
                }

                viewHolder.userNameText?.text = entry.message.sender.userId
                viewHolder.dateText?.text =
                    DateFormat.getTimeInstance(DateFormat.SHORT).format(entry.message.sendTime)
            }

            is ChatEntry.PendingRequest -> {
                viewHolder.container.setBackgroundColor(ContextCompat.getColor(context!!, R.color.light_gray))
                viewHolder.textView.text = entry.request.content
                viewHolder.failedMark.isGone = true
                viewHolder.itemView.setOnCreateContextMenuListener(null)
                viewHolder.dateText?.text = "Sending"
            }

            is ChatEntry.FailedRequest -> {
                viewHolder.textView.text = entry.request.content
                viewHolder.container.setBackgroundColor(ContextCompat.getColor(context!!, R.color.dark_red))
                viewHolder.failedMark.isGone = false
                viewHolder.dateText?.text = "Failed"
            }
        }
    }

    override fun onAttachedToRecyclerView(recyclerView: RecyclerView) {
        super.onAttachedToRecyclerView(recyclerView)
        context = recyclerView.context
    }

    override fun getItemCount() = entries.entries.size
}

最终步骤

现在可以挂载我们的新适配器，将 ChatEntries 类绑定到 MainActivity：

Kotlin：

// ./app/src/main/java/com/chatterbox/myapp/MainActivity.kt

package com.chatterbox.myapp
// ...

import com.chatterbox.myapp.databinding.ActivityMainBinding
import com.chatterbox.myapp.ChatListAdapter
import com.chatterbox.myapp.ChatEntries

class MainActivity : AppCompatActivity() {
    // ...
    private var entries = ChatEntries()
    private lateinit var adapter: ChatListAdapter
    private lateinit var binding: ActivityMainBinding

    /* see https://developer.android.com/topic/libraries/data-binding/generated-binding#create */
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        /* Create room instance. */
        room = ChatRoom(REGION, ::fetchChatToken).apply {
            listener = roomListener
        }

        binding.sendButton.setOnClickListener(::sendButtonClick)
        binding.connectButton.setOnClickListener { connect() }

        setUpChatView()

        updateConnectionState(ConnectionState.DISCONNECTED)
    }

    private fun setUpChatView() {
        /* Setup Android Jetpack RecyclerView - see https://developer.android.com/develop/ui/views/layout/recyclerview.*/
        adapter = ChatListAdapter(entries, ::disconnectUser)
        entries.adapter = adapter

        val recyclerViewLayoutManager = LinearLayoutManager(this@MainActivity, LinearLayoutManager.VERTICAL, false)
        binding.recyclerView.layoutManager = recyclerViewLayoutManager
        binding.recyclerView.adapter = adapter

        binding.sendButton.setOnClickListener(::sendButtonClick)
        binding.messageEditText.setOnEditorActionListener { _, _, event ->
            val isEnterDown = (event.action == KeyEvent.ACTION_DOWN) && (event.keyCode == KeyEvent.KEYCODE_ENTER)
            if (!isEnterDown) {
                return@setOnEditorActionListener false
            }

            sendButtonClick(binding.sendButton)
            return@setOnEditorActionListener true
        }
    }
}

由于我们已经有一个用于负责跟踪我们聊天请求的类 (ChatEntries)，我们已经准备好实现用于在 roomListener 中操作 entries 的代码。我们将根据自己正在响应的事件来更新 entries 和 connectionState：

Kotlin：

// ./app/src/main/java/com/chatterbox/myapp/MainActivity.kt

package com.chatterbox.myapp
// ...

class MainActivity : AppCompatActivity() {
    //...
    

    private fun sendMessage(request: SendMessageRequest) {
    //...

    }

    private fun scrollToBottom() {
        binding.recyclerView.smoothScrollToPosition(entries.size - 1)
    }

    private val roomListener = object : ChatRoomListener {
        override fun onConnecting(room: ChatRoom) {
            Log.d(TAG, "[${Thread.currentThread().name}] onConnecting")
            runOnUiThread {
                updateConnectionState(ConnectionState.LOADING)
            }
        }

        override fun onConnected(room: ChatRoom) {
            Log.d(TAG, "[${Thread.currentThread().name}] onConnected")
            runOnUiThread {
                updateConnectionState(ConnectionState.CONNECTED)
            }
        }

        override fun onDisconnected(room: ChatRoom, reason: DisconnectReason) {
            Log.d(TAG, "[${Thread.currentThread().name}] onDisconnected")
            runOnUiThread {
                updateConnectionState(ConnectionState.DISCONNECTED)
                entries.removeAll()
            }
        }

        override fun onMessageReceived(room: ChatRoom, message: ChatMessage) {
            Log.d(TAG, "[${Thread.currentThread().name}] onMessageReceived $message")
            runOnUiThread {
                entries.addReceivedMessage(message)
                scrollToBottom()
            }
        }

        override fun onEventReceived(room: ChatRoom, event: ChatEvent) {
            Log.d(TAG, "[${Thread.currentThread().name}] onEventReceived $event")
        }

        override fun onMessageDeleted(room: ChatRoom, event: DeleteMessageEvent) {
            Log.d(TAG, "[${Thread.currentThread().name}] onMessageDeleted $event")
        }

        override fun onUserDisconnected(room: ChatRoom, event: DisconnectUserEvent) {
            Log.d(TAG, "[${Thread.currentThread().name}] onUserDisconnected $event")
        }
    }
}

现在应该可以运行您的应用程序了！（请参阅构建和运行您的应用程序。） 使用应用程序时，请记住让您的后端服务器保持运行。您可以通过使用命令 ./gradlew :auth-server:run，从我们项目根目录的终端启动，或是直接从 Android Studio 执行 auth-server:run Gradle 任务来启动。