diff --git a/app/src/main/java/com/example/login_v3/home/Message/UI/Detail/Message_Messaging.kt b/app/src/main/java/com/example/login_v3/home/Message/UI/Detail/Message_Messaging.kt
index 99d05dc..8b69c36 100644
--- a/app/src/main/java/com/example/login_v3/home/Message/UI/Detail/Message_Messaging.kt
+++ b/app/src/main/java/com/example/login_v3/home/Message/UI/Detail/Message_Messaging.kt
@@ -19,26 +19,35 @@ import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material.icons.automirrored.filled.Send
 import androidx.compose.material.icons.filled.AccountCircle
 import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material.icons.filled.Send
 import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
+import androidx.compose.material3.TextField
+import androidx.compose.material3.TextFieldDefaults
 import androidx.compose.material3.TopAppBar
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.unit.dp
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
@@ -63,6 +72,7 @@ fun MessageMessaging(
 ) {
     val uiState by viewModel.uiState.collectAsStateWithLifecycle()
 
+
     LaunchedEffect(roomId) {
         viewModel.loadMessages(roomId)
     }
@@ -255,4 +265,64 @@ fun UserAvatar(
             .clip(CircleShape),
         contentScale = ContentScale.Crop
     )
+}
+
+
+@Composable
+fun MessageInputBar(
+    isLoading: Boolean,
+    onSendClick: (String) -> Unit,
+    modifier: Modifier = Modifier
+) {
+    var textInput by remember { mutableStateOf("") }
+
+    // 當發送成功、外面將 isLoading 從 true 變回 false 時，可以順便清空輸入框
+    // 這裡直接在點擊發送時清空，或由外面控制皆可。
+
+    Surface(
+        tonalElevation = 2.dp,
+        modifier = modifier.fillMaxWidth()
+    ) {
+        Row(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(horizontal = 8.dp, vertical = 4.dp),
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            TextField(
+                value = textInput,
+                onValueChange = { textInput = it },
+                placeholder = { Text("輸入訊息...") },
+                modifier = Modifier.weight(1.0f),
+                colors = TextFieldDefaults.colors(
+                    focusedContainerColor = Color.Transparent,
+                    unfocusedContainerColor = Color.Transparent,
+                    disabledContainerColor = Color.Transparent,
+                    focusedIndicatorColor = Color.Transparent,
+                    unfocusedIndicatorColor = Color.Transparent
+                ),
+                maxLines = 4
+            )
+
+            IconButton(
+                onClick = {
+                    if (textInput.isNotBlank() && !isLoading) {
+                        onSendClick(textInput)
+                        textInput = "" // 點擊後立即清空輸入框
+                    }
+                },
+                enabled = textInput.isNotBlank() && !isLoading
+            ) {
+                if (isLoading) {
+                    CircularProgressIndicator(modifier = Modifier.size(24.dp), strokeWidth = 2.dp)
+                } else {
+                    Icon(
+                        imageVector = Icons.Default.Send,
+                        contentDescription = "發送訊息",
+                        tint = if (textInput.isNotBlank()) Color(0xFFDA7029) else Color.Gray
+                    )
+                }
+            }
+        }
+    }
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/example/login_v3/home/Message/ViewModel/Message_ViewModel.kt b/app/src/main/java/com/example/login_v3/home/Message/ViewModel/Message_ViewModel.kt
index 4e4bc70..eb2283a 100644
--- a/app/src/main/java/com/example/login_v3/home/Message/ViewModel/Message_ViewModel.kt
+++ b/app/src/main/java/com/example/login_v3/home/Message/ViewModel/Message_ViewModel.kt
@@ -7,6 +7,7 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.example.login_v3.R
 import com.example.login_v3.data.api.api_class.ChatRoom
+import com.example.login_v3.data.api.api_class.Message
 import com.example.login_v3.data.repository.dm.ChatRoomsRepository
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -15,6 +16,16 @@ import kotlinx.coroutines.launch
 import javax.inject.Inject
 
 
+
+//message sending state
+sealed class SendMessageState {
+    object Idle : SendMessageState()      // 閒置狀態（預設）
+    object Loading : SendMessageState()   // 發送中
+    data class Success(val message: Message) : SendMessageState() // 發送成功，並帶回新訊息
+    data class Error(val message: String) : SendMessageState()    // 發送失敗，帶有錯誤訊息
+}
+
+
 @HiltViewModel
 class ChatRoomsViewModel @Inject constructor(
     private val repository: ChatRoomsRepository
@@ -23,13 +34,16 @@ class ChatRoomsViewModel @Inject constructor(
     private val _roomsState = MutableStateFlow<List<ChatRoom>>(emptyList())
     val roomsState: StateFlow<List<ChatRoom>> = _roomsState
 
+    // 1. 新增：發送訊息的 UI 狀態 Flow
+    private val _sendMessageState = MutableStateFlow<SendMessageState>(SendMessageState.Idle)
+    val sendMessageState: StateFlow<SendMessageState> = _sendMessageState
+
     fun loadRooms() {
         viewModelScope.launch {
             val result = repository.fetchRooms()
             result.onSuccess { response ->
                 _roomsState.value = response.rooms
 
-                // 打印偵錯訊息
                 response.rooms.forEach { room ->
                     val status = room.partner?.status
                     val name = room.partner?.displayName
@@ -40,6 +54,38 @@ class ChatRoomsViewModel @Inject constructor(
             }
         }
     }
+
+    // 2. 新增：發送訊息的 function
+    fun sendMessage(roomId: String, content: String, replyToId: String? = null) {
+        // 如果內容是空的，就直接攔截不送出
+        if (content.isBlank()) return
+
+        viewModelScope.launch {
+            // 切換成載入中狀態
+            _sendMessageState.value = SendMessageState.Loading
+
+            // 呼叫 repository
+            val result = repository.sendMessage(roomId, content, replyToId)
+
+            result.onSuccess { newMessage ->
+                // 發送成功
+                _sendMessageState.value = SendMessageState.Success(newMessage)
+
+                // 【可選】如果你的聊天訊息列表也是歸這個 ViewModel 管，
+                // 你可以在這裡順便把新訊息加進當前的訊息列表 Flow 中，這樣畫面就會立刻跳出新訊息。
+
+            }.onFailure { error ->
+                // 發送失敗
+                Log.e("ChatRoomsViewModel", "Send message failed", error)
+                _sendMessageState.value = SendMessageState.Error(error.message ?: "未知錯誤")
+            }
+        }
+    }
+
+    // 3. 新增：重設發送狀態（通常在 UI 顯示完錯誤跳出視窗、或成功送出清空輸入框後呼叫）
+    fun resetSendMessageState() {
+        _sendMessageState.value = SendMessageState.Idle
+    }
 }
 
 enum class UserStatus(val color: Color) {
@@ -60,4 +106,4 @@ enum class UserStatus(val color: Color) {
             }
         }
     }
-}
+}
\ No newline at end of file