zhibo/android-app/app/src/main/res/layout/activity_conversation.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="match_parent"
    android:background="@android:color/white">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/topBar"
        android:layout_width="0dp"
        android:layout_height="56dp"
        android:background="@android:color/white"
        android:paddingStart="8dp"
        android:paddingEnd="16dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <ImageButton
            android:id="@+id/backButton"
            android:layout_width="40dp"
            android:layout_height="40dp"
            android:background="@android:color/transparent"
            android:contentDescription="back"
            android:padding="8dp"
            android:src="@drawable/ic_arrow_back_24"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <ImageView
            android:id="@+id/avatarView"
            android:layout_width="36dp"
            android:layout_height="36dp"
            android:layout_marginStart="4dp"
            android:background="@drawable/bg_avatar_circle"
            android:padding="5dp"
            android:src="@drawable/ic_account_circle_24"
            app:layout_constraintBottom_toBottomOf="@id/backButton"
            app:layout_constraintStart_toEndOf="@id/backButton"
            app:layout_constraintTop_toTopOf="@id/backButton" />

        <TextView
            android:id="@+id/titleText"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginStart="10dp"
            android:ellipsize="end"
            android:maxLines="1"
            android:text="会话"
            android:textColor="#111111"
            android:textSize="16sp"
            android:textStyle="bold"
            app:layout_constraintBottom_toBottomOf="@id/avatarView"
            app:layout_constraintEnd_toStartOf="@id/voiceCallButton"
            app:layout_constraintStart_toEndOf="@id/avatarView"
            app:layout_constraintTop_toTopOf="@id/avatarView" />

        <!-- 语音通话按钮 -->
        <ImageButton
            android:id="@+id/voiceCallButton"
            android:layout_width="40dp"
            android:layout_height="40dp"
            android:background="?attr/selectableItemBackgroundBorderless"
            android:contentDescription="语音通话"
            android:padding="8dp"
            android:src="@drawable/ic_call"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toStartOf="@id/videoCallButton"
            app:layout_constraintTop_toTopOf="parent"
            app:tint="#FF6B6B" />

        <!-- 视频通话按钮 -->
        <ImageButton
            android:id="@+id/videoCallButton"
            android:layout_width="40dp"
            android:layout_height="40dp"
            android:background="?attr/selectableItemBackgroundBorderless"
            android:contentDescription="视频通话"
            android:padding="8dp"
            android:src="@drawable/ic_videocam"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:tint="#FF6B6B" />

    </androidx.constraintlayout.widget.ConstraintLayout>

    <View
        android:id="@+id/topDivider"
        android:layout_width="0dp"
        android:layout_height="1dp"
        android:background="#EEEEEE"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/topBar" />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/messagesRecyclerView"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:clipToPadding="false"
        android:overScrollMode="never"
        android:paddingTop="6dp"
        android:paddingBottom="6dp"
        app:layout_constraintBottom_toTopOf="@id/replyInputContainer"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/topDivider" />

    <!-- 回复预览区域（正在回复某条消息时显示） -->
    <LinearLayout
        android:id="@+id/replyInputContainer"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:background="#F5F5F5"
        android:padding="10dp"
        android:gravity="center_vertical"
        android:visibility="gone"
        app:layout_constraintBottom_toTopOf="@id/inputBar"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent">

        <!-- 左侧竖线 -->
        <View
            android:layout_width="3dp"
            android:layout_height="match_parent"
            android:background="#4CAF50"
            android:layout_marginEnd="10dp" />

        <!-- 回复内容 -->
        <LinearLayout
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:orientation="vertical">

            <TextView
                android:id="@+id/replyInputLabel"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="回复 用户名"
                android:textColor="#4CAF50"
                android:textSize="12sp"
                android:textStyle="bold" />

            <TextView
                android:id="@+id/replyInputContent"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="消息内容预览"
                android:textColor="#666666"
                android:textSize="12sp"
                android:maxLines="1"
                android:ellipsize="end"
                android:layout_marginTop="2dp" />

        </LinearLayout>

        <!-- 关闭按钮 -->
        <ImageView
            android:id="@+id/replyInputClose"
            android:layout_width="24dp"
            android:layout_height="24dp"
            android:src="@drawable/ic_close_24"
            android:padding="4dp"
            android:background="?attr/selectableItemBackgroundBorderless"
            android:contentDescription="取消回复" />

    </LinearLayout>

    <LinearLayout
        android:id="@+id/inputBar"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:background="#FAFAFA"
        android:gravity="center_vertical"
        android:orientation="horizontal"
        android:paddingStart="12dp"
        android:paddingEnd="12dp"
        android:paddingTop="10dp"
        android:paddingBottom="10dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent">

        <com.google.android.material.textfield.TextInputEditText
            android:id="@+id/messageInput"
            android:layout_width="0dp"
            android:layout_height="40dp"
            android:layout_weight="1"
            android:background="@drawable/bg_white_16"
            android:hint="输入消息..."
            android:imeOptions="actionSend"
            android:inputType="text"
            android:maxLines="4"
            android:paddingStart="12dp"
            android:paddingEnd="12dp"
            android:textColor="#111111"
            android:textSize="14sp" />

        <com.google.android.material.button.MaterialButton
            android:id="@+id/sendButton"
            android:layout_width="wrap_content"
            android:layout_height="40dp"
            android:layout_marginStart="10dp"
            android:minWidth="64dp"
            android:text="发送"
            android:textAllCaps="false"
            android:textSize="13sp" />

    </LinearLayout>

</androidx.constraintlayout.widget.ConstraintLayout>