添加时间格式化和历史记录功能

在 `ChatDataModel.cs` 中添加 `TimeFormatConverter` 类，用于格式化本地时间，并在 `MainWindow.xaml` 中应用该转换器。
在 `chatapi.cs` 中新增 `HistoryRequest` 和 `HistoryResponse` 类以处理历史记录请求和响应。
修改 `LoginWindow.xaml.cs` 中的数据发送方式，使用 `SendWithPrefix` 方法以支持数据压缩和长度前缀。
在 `MainWindow.xaml.cs` 中添加 `LoadHistoryMessages` 方法以加载历史消息，并在接收到响应时更新消息列表。
在 `Program.cs` 中实现数据压缩和解压缩方法，提升网络传输效率。
新增消息表和索引以支持消息存储和查询。
更新日志记录以提供更详细的操作信息和错误处理。

chatclient/Data/ChatDataModel.cs

@@ -8,6 +8,8 @@ using System.Windows;
 using System.Windows.Media.Imaging;
 using System.Windows.Controls;
 using System.Windows.Input;
+using System.Globalization;
+using System.Windows.Data;
 
 namespace chatclient.Data
 {
@@ -60,4 +62,75 @@ namespace chatclient.Data
         public string? UserName { get; set; }
         public string? UserPassword { get; set; }
     }
+    /// <summary>
+    /// 时间格式转换器类
+    /// </summary>
+    public class TimeFormatConverter : IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            if (value is DateTime timestamp)
+            {
+                // 获取本地时区信息
+                TimeZoneInfo localTimeZone = TimeZoneInfo.Local;
+                bool isLocalTimeZoneUtcPlus8 = localTimeZone.BaseUtcOffset == TimeSpan.FromHours(8);
+                DateTime localTime;
+                if (timestamp.Kind == DateTimeKind.Utc)
+                {
+                    localTime = timestamp.ToLocalTime();
+                }
+                else if (timestamp.Kind == DateTimeKind.Unspecified)
+                {
+                    // 假设未指定时间是UTC时间（常见实践）
+                    localTime = DateTime.SpecifyKind(timestamp, DateTimeKind.Utc).ToLocalTime();
+                }
+                else
+                {
+                    localTime = timestamp;
+                }
+
+                var now = DateTime.Now;
+                var today = now.Date;
+                var yesterday = today.AddDays(-1);
+                var localTimeDate = localTime.Date;
+
+                // 格式化时间字符串
+                string formattedTime;
+                if (localTimeDate == today)
+                {
+                    formattedTime = localTime.ToString("HH:mm:ss");
+                }
+                else if (localTimeDate == yesterday)
+                {
+                    formattedTime = "昨天 " + localTime.ToString("HH:mm");
+                }
+                else if (localTime.Year == now.Year)
+                {
+                    formattedTime = localTime.ToString("MM/dd HH:mm");
+                }
+                else
+                {
+                    formattedTime = localTime.ToString("yy/MM/dd HH:mm");
+                }
+
+                // 仅在非UTC+8时区显示时区信息
+                if (!isLocalTimeZoneUtcPlus8)
+                {
+                    // 获取原始时间的时区信息
+                    string timeZoneInfo = timestamp.Kind == DateTimeKind.Utc
+                        ? "UTC"
+                        : "UTC"+localTime.ToString("zzz");
+
+                    return $"{timeZoneInfo} {formattedTime}";
+                }
+                return formattedTime;
+            }
+            return value;
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            throw new NotImplementedException();
+        }
+    }
 }

chatclient/Data/chatapi.cs

@@ -5,8 +5,8 @@ namespace chatclient.Data
     internal class Server 
     {
         public const string ServerUrl = "http://127.0.0.1:5001";
-        //public const string ServerIP = "175.24.191.172";
+        public const string ServerIP = "175.24.191.172";
-        public const string ServerIP = "127.0.0.1";
+        //public const string ServerIP = "127.0.0.1";
         public const int ServerPort = 52006;
     }
     internal class LoginData
@@ -57,4 +57,25 @@ namespace chatclient.Data
         public required string userid { get; set; } = "Unid";
         public string? token { get; set; } = null;  // 添加token字段
     }
+    /// <summary>
+    /// 历史记录请求类
+    /// </summary>
+    internal class HistoryRequest
+    {
+        public string type { get; set; } = "history";
+        public int offset { get; set; } = 0; // 分页偏移量
+        public int count { get; set; } = 10; // 请求数量
+        public string? chat_type { get; set; } = "group"; // group/private
+        public string? room_id { get; set; } = "global"; // 群聊房间ID
+        public string? receiver_id { get; set; } = null; // 私聊接收者ID
+    }
+
+    /// <summary>
+    /// 历史记录响应类
+    /// </summary>
+    internal class HistoryResponse
+    {
+        public List<ChatRegisterData> history { get; set; } = new List<ChatRegisterData>();
+        public int total_count { get; set; } // 总消息数
+    }
 }

chatclient/LoginWindow.xaml.cs

@@ -150,7 +150,7 @@ namespace chatclient
             // 检查Socket是否可用
             if (MainWindow.Client?.Connected == true)
             {
-                MainWindow.Client.Send(dataBytes);
+                MainWindow.SendWithPrefix(dataBytes);
                 return;
             }
             log.Info("未连接服务器，尝试异步连接");
@@ -162,7 +162,7 @@ namespace chatclient
                     MainWindow.Client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                     MainWindow.Client?.Connect(IPAddress.Parse(Server.ServerIP), Server.ServerPort);
                     MainWindow.StartReceive();
-                    MainWindow.Client?.Send(dataBytes);
+                    MainWindow.SendWithPrefix(dataBytes);
                 }
                 catch (Exception ex)
                 {
@@ -235,7 +235,7 @@ namespace chatclient
             // 检查Socket是否可用
             if (MainWindow.Client?.Connected == true)
             {
-                MainWindow.Client.Send(dataBytes);
+                MainWindow.SendWithPrefix(dataBytes);
                 return;
             }
             log.Info("未连接服务器，尝试异步连接");
@@ -247,7 +247,7 @@ namespace chatclient
                     MainWindow.Client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                     MainWindow.Client?.Connect(IPAddress.Parse(Server.ServerIP), Server.ServerPort);
                     MainWindow.StartReceive();
-                    MainWindow.Client?.Send(dataBytes);
+                    MainWindow.SendWithPrefix(dataBytes);
                 }
                 catch (Exception ex)
                 {

chatclient/MainWindow.xaml

@@ -5,10 +5,14 @@
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:materialDesign="http://materialdesigninxaml.net/winfx/xaml/themes"
         xmlns:local="clr-namespace:chatclient"
+        xmlns:data="clr-namespace:chatclient.Data"
         xmlns:mah="http://metro.mahapps.com/winfx/xaml/controls" x:Class="chatclient.MainWindow"
         mc:Ignorable="d"
         Title="ChatWindow" Height="450" Width="800" MinHeight="240" MinWidth="380"
         Style="{StaticResource MaterialDesignWindow}" Closed="MainWindow_Closed" Loaded="MainWindow_Loaded">
+    <Window.Resources>
+        <data:TimeFormatConverter x:Key="TimeConverter"/>
+    </Window.Resources>
     <Grid>
         <materialDesign:Card>
             <TabControl x:Name="TabControl" VerticalContentAlignment="Bottom" materialDesign:ColorZoneAssist.Mode="PrimaryMid" Style="{StaticResource MaterialDesignNavigationRailTabControl}">
@@ -75,7 +79,7 @@
                                                     <StackPanel>
                                                         <TextBlock Text="{Binding Sender}" x:Name="Sender" FontWeight="Bold" Foreground="{Binding SenderColor}"/>
                                                         <TextBlock Text="{Binding Content}" TextWrapping="Wrap" Margin="0,5,0,0"/>
-                                                        <TextBlock Text="{Binding Timestamp, StringFormat='HH:mm:ss'}" x:Name="Timestamp" Foreground="Gray"  FontSize="10" HorizontalAlignment="Right"  Margin="0,5,0,0"/>
+                                                        <TextBlock Text="{Binding Timestamp, Converter={StaticResource TimeConverter}}" x:Name="Timestamp" Foreground="Gray"  FontSize="10" HorizontalAlignment="Right"  Margin="0,5,0,0"/>
                                                     </StackPanel>
                                                 </materialDesign:Card>
                                                 <!-- 右侧头像（仅当Alignment=Right时显示） -->

chatclient/MainWindow.xaml.cs

@@ -22,6 +22,7 @@ using System.Collections.ObjectModel;
 using System.Windows.Threading;
 using System.Collections.Specialized;
 using Hardcodet.Wpf.TaskbarNotification;
+using System.IO.Compression;
 
 [assembly: XmlConfigurator(ConfigFile = "config/log4net.config", Watch = true)]
 namespace chatclient
@@ -32,10 +33,11 @@ namespace chatclient
     public partial class MainWindow : Window, INotifyPropertyChanged
     {
         LoginWindow Login = new();
-        static string? receive;
+        //static string? receive;
         public static string UserName { get; set; } = "?";
         public static string? token = null;
         public static string? UserId = null;
+        //private bool isLoadingHistory = false;
         private static readonly ILog log = LogManager.GetLogger(typeof(MainWindow));
         public static Socket? Client;
         public static readonly HttpClient HttpClient = new HttpClient();
@@ -87,8 +89,6 @@ namespace chatclient
                     MessageScroller.ScrollToEnd();
                 }), DispatcherPriority.ContextIdle);
             };
-            //Loaded += MainWindow_Loaded;
-            //Closed += MainWindow_Closed;
         }
         public static void StartReceive()
         {
@@ -101,29 +101,64 @@ namespace chatclient
         }
         static void Receive()
         {
-            byte[] buffer = new byte[1024];
+            const int prefixSize = sizeof(int);
+            byte[] prefixBuffer = new byte[prefixSize];
+            MemoryStream receivedStream = new MemoryStream();
             try
             {
                 while (true)
                 {
-                    int num = Client!.Receive(buffer);
+                    //接收前缀长度
-                    if (num == 0) break;
+                    int prefixBytesRead = 0;
-                    if (Client.Poll(100, SelectMode.SelectRead) && Client.Available == 0 || !Client.Connected)
+                    while (prefixBytesRead < prefixSize)
                     {
-                        log.Error("连接已断开");
+                        int bytesRead = Client!.Receive(prefixBuffer, prefixBytesRead, prefixSize - prefixBytesRead, SocketFlags.None);
-                        break;
+                        if (bytesRead == 0)
+                        {
+                            log.Info("连接已关闭");
+                            return;
+                        }
+                        prefixBytesRead += bytesRead;
                     }
-                    receive = Encoding.UTF8.GetString(buffer, 0, num);
+                    //解析消息长度
-                    response(receive);
+                    int messageLength = BitConverter.ToInt32(prefixBuffer, 0);
+                    if (messageLength <= 0 || messageLength > 10 * 1024 * 1024)
+                    {
+                        log.Error($"无效消息长度: {messageLength}");
+                        continue;
+                    }
+                    //读取完整消息
+                    byte[] messageBuffer = new byte[messageLength];
+                    int totalBytesRead = 0;
+                    while (totalBytesRead < messageLength)
+                    {
+                        int bytesRead = Client!.Receive(messageBuffer, totalBytesRead, messageLength - totalBytesRead, SocketFlags.None);
+                        if (bytesRead == 0)
+                        {
+                            log.Info("连接已关闭");
+                            return;
+                        }
+                        totalBytesRead += bytesRead;
+                    }
+                    //解压缩
+                    byte[] decompressedData = Decompress(messageBuffer);
+                    //处理消息
+                    string message = Encoding.UTF8.GetString(decompressedData);
+                    response(message);
                 }
             }
+            catch (SocketException ex)
+            {
+                log.Error($"Socket错误: {ex.SocketErrorCode}");
+            }
             catch (Exception ex)
             {
-                log.Error(ex);
+                log.Error($"接收错误: {ex.Message}");
             }
             finally
             {
                 Client?.Close();
+                receivedStream.Dispose();
             }
         }
         static void response(string msg)
@@ -165,6 +200,7 @@ namespace chatclient
                                     mainWindow?.Messages.Add(chatmessage);
                                 }
                             });
+                            LoadHistoryMessages();
                             log.Info($"用户 {UserName} 登录成功(token:{token},userid:{UserId})");
                         }
                         else if (LoginResponse!.status == "error_0")
@@ -325,6 +361,45 @@ namespace chatclient
                             log.Error("反序列化聊天数据时返回了 null");
                         }
                     }
+                    else if (Type.type == "history")
+                    {
+                        var historyResponse = JsonSerializer.Deserialize<HistoryResponse>(msg);
+                        Application.Current.Dispatcher.Invoke(() =>
+                        {
+                            var mainWindow = Application.Current.Windows.OfType<MainWindow>().FirstOrDefault();
+                            if (mainWindow == null) return;
+                            if (historyResponse?.history != null)
+                            {
+                                foreach (var msgItem in historyResponse.history)
+                                {
+                                    try
+                                    {
+                                        mainWindow.Dispatcher.Invoke(() =>
+                                        {
+                                            var chatmessage = new ChatMessage
+                                            {
+                                                Sender = msgItem.user ?? "未知用户",
+                                                MsgType = MessageType.Text,
+                                                Image = new BitmapImage(new Uri(
+                                                    "pack://application:,,,/resource/user.png",
+                                                    UriKind.Absolute)),
+                                                Content = msgItem.message ?? "(无内容)",
+                                                Timestamp = msgItem.timestamp ?? DateTime.Now,
+                                                Alignment = msgItem.userid == UserId ?
+                                                           HorizontalAlignment.Right :
+                                                           HorizontalAlignment.Left
+                                            };
+                                            mainWindow.Messages.Insert(0, chatmessage);
+                                        });
+                                    }
+                                    catch (Exception ex)
+                                    {
+                                        log.Error($"添加历史消息失败: {ex.Message}");
+                                    }
+                                }
+                            }
+                        });
+                    }
                     else if (Type.type == "ping") { }
                     else
                     {
@@ -346,6 +421,58 @@ namespace chatclient
                 log.Error("处理响应时发生错误", ex);
             }
         }
+        /// <summary>
+        /// 压缩数据
+        /// </summary>
+        /// <param name="data"></param>
+        /// <returns></returns>
+        private static byte[] Compress(byte[] data)
+        {
+            if (data.Length < 256)
+                return data;
+
+            using (var compressedStream = new MemoryStream())
+            {
+                using (var zipStream = new GZipStream(compressedStream, CompressionMode.Compress))
+                {
+                    zipStream.Write(data, 0, data.Length);
+                }
+                return compressedStream.ToArray();
+            }
+        }
+        /// <summary>
+        /// 解压缩数据
+        /// </summary>
+        /// <param name="compressedData"></param>
+        /// <returns></returns>
+        private static byte[] Decompress(byte[] compressedData)
+        {
+            if (compressedData.Length < 2 || compressedData[0] != 0x1F || compressedData[1] != 0x8B)
+                return compressedData; // 未压缩数据
+
+            using (var compressedStream = new MemoryStream(compressedData))
+            using (var zipStream = new GZipStream(compressedStream, CompressionMode.Decompress))
+            using (var resultStream = new MemoryStream())
+            {
+                zipStream.CopyTo(resultStream);
+                return resultStream.ToArray();
+            }
+        }
+        /// <summary>
+        /// 发送消息
+        /// </summary>
+        /// <param name="data"></param>
+        public static void SendWithPrefix(byte[] data)
+        {
+            byte[] compressedData = Compress(data);
+            byte[] lengthPrefix = BitConverter.GetBytes(compressedData.Length);
+            byte[] fullMessage = new byte[lengthPrefix.Length + compressedData.Length];
+
+            Buffer.BlockCopy(lengthPrefix, 0, fullMessage, 0, lengthPrefix.Length);
+            Buffer.BlockCopy(compressedData, 0, fullMessage, lengthPrefix.Length, compressedData.Length);
+            log.Info($"发送数据(长度:{data.Length},压缩后长度:{lengthPrefix.Length},总体长度:{fullMessage.Length})");
+            Client?.Send(fullMessage);
+        }
         private async void SendMessage_Click(object sender, RoutedEventArgs e)
         {
             await SendMessage();
@@ -354,24 +481,10 @@ namespace chatclient
         {
             if (string.IsNullOrWhiteSpace(txtMessage.Text))
                 return;
-
             // 获取当前选中的联系人
             //var contact = cmbContacts.SelectedItem as Contact;
             // 判断是否为群组，若是则收件人设为“所有人”，否则为联系人显示名
             //string recipient = contact?.IsGroup == true ? "所有人" : contact?.DisplayName;
-
-            // 弃用的方法
-            // 创建新消息
-            //var newMessage = new ChatMessage
-            //{
-            //    Sender = "我",
-            //    Type = MessageType.Text,
-            //    Image = new BitmapImage(new Uri("pack://application:,,,/resource/user.png", UriKind.Absolute)), // 默认头像
-            //    Content = txtMessage.Text,
-            //    Timestamp = DateTime.Now,
-            //    Alignment = HorizontalAlignment.Right, // 自己发送的消息靠右
-            //    SenderColor = new SolidColorBrush(Colors.Blue)
-            //};
             var newChatMessage = new ChatData
             {
                 type = "chat",
@@ -386,7 +499,7 @@ namespace chatclient
             // 检查Socket是否可用
             if (Client?.Connected == true)
             {
-                Client.Send(dataBytes);
+                SendWithPrefix(dataBytes);
                 Application.Current.Dispatcher.Invoke(() => 
                 {
                     txtMessage.Clear();
@@ -402,7 +515,7 @@ namespace chatclient
                     Client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                     Client?.Connect(IPAddress.Parse(Server.ServerIP), Server.ServerPort);
                     StartReceive();
-                    Client?.Send(dataBytes);
+                    SendWithPrefix(dataBytes);
                     Application.Current.Dispatcher.Invoke(() =>
                     {
                         txtMessage.Clear();
@@ -425,6 +538,38 @@ namespace chatclient
             // 添加到消息列表
             //Messages.Add(newMessage);
         }
+        private static void LoadHistoryMessages(int offset = 0)
+        {
+            var historyRequest = new HistoryRequest
+            {
+                offset = offset,
+                count = 10,
+                chat_type = "group",
+                room_id = "global"
+            };
+            string requestData = JsonSerializer.Serialize(historyRequest);
+            byte[] data = Encoding.UTF8.GetBytes(requestData);
+            if (Client?.Connected == true)
+            {
+                try
+                {
+                    SendWithPrefix(data);
+                }
+                catch (SocketException ex)
+                {
+                    log.Error($"发送历史请求失败: {ex.SocketErrorCode}");
+                }
+                catch (Exception ex)
+                {
+                    log.Error($"发送历史请求异常: {ex.Message}");
+                }
+            }
+            else
+            {
+                // 处理断开连接的情况  
+                log.Warn("发送历史请求时客户端未连接");
+            }
+        }
         private void QueueMessage(string message)
         {
             if (SnackbarThree.MessageQueue is { } messageQueue)

chatserver/Data/chatapi.cs

@@ -6,12 +6,18 @@ using System.Threading.Tasks;
 
 namespace chatserver.Data
 {
+    /// <summary>
+    /// 登录请求类
+    /// </summary>
     internal class LoginData
     {
         public string? username { get; set; } = null;
         public string? password { get; set; } = null;
         public string? token { get; set; } = null;
     }
+    /// <summary>
+    /// 登录响应类
+    /// </summary>
     internal class LoginResultData
     {
         public required string type { get; set; } = "login";
@@ -21,21 +27,33 @@ namespace chatserver.Data
         public string? token { get; set; }
         public string? username { get; set; }
     }
+    /// <summary>
+    /// 注册请求类
+    /// </summary>
     internal class SignData
     {
         public string? username { get; set; } = null;
         public string? password { get; set; } = null;
     }
+    /// <summary>
+    /// 注册响应类
+    /// </summary>
     internal class SignResultData
     {
         public required string type { get; set; } = "sign";
         public string? status { get; set; } = null;
         public string? message { get; set; } = null;
     }
+    /// <summary>
+    /// 类型数据类
+    /// </summary>
     internal class TypeData
     {
         public string? type { get; set; }
     }
+    /// <summary>
+    /// 聊天数据响应类
+    /// </summary>
     internal class ChatRegisterData
     {
         public required string type { get; set; } = "chat";
@@ -47,6 +65,9 @@ namespace chatserver.Data
         public MessageType? msgtype { get; set; } = MessageType.Text;
         public DateTime? timestamp { get; set; } = DateTime.Now;
     }
+    /// <summary>
+    /// 聊天数据请求类
+    /// </summary>
     internal class ChatData
     {
         public required string message { get; set; } = "message";
@@ -54,4 +75,25 @@ namespace chatserver.Data
         public required string userid { get; set; } = "Unid";
         public string? token { get; set; } = null;  // 添加token字段
     }
+    /// <summary>
+    /// 历史记录请求类
+    /// </summary>
+    internal class HistoryRequest
+    {
+        public int offset { get; set; } = 0; // 分页偏移量
+        public int count { get; set; } = 10; // 请求数量
+        public string? chat_type { get; set; } = "group"; // group/private
+        public string? room_id { get; set; } = "global"; // 群聊房间ID
+        public string? receiver_id { get; set; } = null; // 私聊接收者ID
+    }
+
+    /// <summary>
+    /// 历史记录响应类
+    /// </summary>
+    internal class HistoryResponse
+    {
+        public string type { get; set; } = "history";
+        public List<ChatRegisterData> history { get; set; } = new List<ChatRegisterData>();
+        public int total_count { get; set; } // 总消息数
+    }
 }

chatserver/Program.cs

@@ -8,6 +8,7 @@ using chatserver.Data;
 using System.Text.Json;
 using System.Reflection;
 using static log4net.Appender.FileAppender;
+using System.IO.Compression;
 
 [assembly: XmlConfigurator(ConfigFile = "config/log4net.config", Watch = true)]
 namespace chatserver
@@ -51,20 +52,47 @@ namespace chatserver
             log.Info("正在打开数据库连接...");
             User_db = new SQLiteConnection("Data Source=ServerUser.db;Version=3;"); //没有数据库则自动创建  
             User_db.Open();
-            EnsureUsersTableExists(); // 确保users表存在
+            InitializeTable();
             log.Info("数据库连接已打开");
         }
         static void HandleClient(Socket socket)
         {
+            const int prefixSize = sizeof(int);
+            byte[] prefixBuffer = new byte[prefixSize];
             try
             {
                 while (true)
-
                 {
-                    byte[] buffer = new byte[1024];
+                    //读取长度前缀
-                    int received = socket.Receive(buffer);
+                    int prefixBytesRead = 0;
-                    if (received == 0) break; // 客户端断开连接  
+                    while (prefixBytesRead < prefixSize)
-                    string message = System.Text.Encoding.UTF8.GetString(buffer, 0, received);
+                    {
+                        int bytesRead = socket.Receive(prefixBuffer, prefixBytesRead, prefixSize - prefixBytesRead, SocketFlags.None);
+                        if (bytesRead == 0)
+                            return;
+                        prefixBytesRead += bytesRead;
+                    }
+                    //解析消息长度
+                    int messageLength = BitConverter.ToInt32(prefixBuffer, 0);
+                    if (messageLength <= 0 || messageLength > 10 * 1024 * 1024)
+                    {
+                        log.Error($"无效消息长度: {messageLength}");
+                        continue;
+                    }
+                    //读取完整消息
+                    byte[] messageBuffer = new byte[messageLength];
+                    int totalBytesRead = 0;
+                    while (totalBytesRead < messageLength)
+                    {
+                        int bytesRead = socket.Receive(messageBuffer, totalBytesRead, messageLength - totalBytesRead, SocketFlags.None);
+                        if (bytesRead == 0)
+                            return;
+                        totalBytesRead += bytesRead;
+                    }
+                    //解压缩
+                    byte[] decompressedData = Decompress(messageBuffer);
+                    string message = System.Text.Encoding.UTF8.GetString(decompressedData);
+                    //处理信息
                     log.Info("Received message: " + message);
                     var Type = JsonSerializer.Deserialize<TypeData>(message);
                     if (Type != null)
@@ -79,28 +107,28 @@ namespace chatserver
                                 {
                                     log.Warn("用户名或密码不能为空");
                                     var emptyResult = new SignResultData { type = "register", status = "error_-1", message = "用户名或密码不能为空" };
-                                    socket.Send(JsonSerializer.SerializeToUtf8Bytes(emptyResult));
+                                    SendWithPrefix(socket,JsonSerializer.SerializeToUtf8Bytes(emptyResult));
                                     continue; // 如果用户名或密码为空，则跳过注册流程
                                 }
                                 if (sginuser.username.Length < 2 || sginuser.username.Length > 20)
                                 {
                                     log.Warn($"用户注册时 {sginuser.username} 用户名长度不符合要求");
                                     var lengthResult = new SignResultData { type = "register", status = "error_2", message = "用户名长度必须在2到20个字符之间" };
-                                    socket.Send(JsonSerializer.SerializeToUtf8Bytes(lengthResult));
+                                    SendWithPrefix(socket,JsonSerializer.SerializeToUtf8Bytes(lengthResult));
                                     continue; // 如果用户名长度不符合要求，则跳过注册流程
                                 }
                                 if (sginuser.password.Length < 4 || sginuser.password.Length > 20)
                                 {
                                     log.Warn($"用户注册时 {sginuser.username} 密码长度不符合要求");
                                     var weakPwdResult = new SignResultData { type = "register", status = "error_1", message = "密码长度必须在4到20个字符之间" };
-                                    socket.Send(JsonSerializer.SerializeToUtf8Bytes(weakPwdResult));
+                                    SendWithPrefix(socket,JsonSerializer.SerializeToUtf8Bytes(weakPwdResult));
                                     continue; // 如果密码过弱，则跳过注册流程
                                 }
                                 if (UserExists(sginuser.username))
                                 {
                                     log.Warn($"用户 {sginuser.username} 已存在");
                                     var Result = new SignResultData { type = "register", status = "error_0", message = "用户名已存在" };
-                                    socket.Send(System.Text.Encoding.UTF8.GetBytes(JsonSerializer.Serialize(Result)));
+                                    SendWithPrefix(socket,System.Text.Encoding.UTF8.GetBytes(JsonSerializer.Serialize(Result)));
                                     continue;// 如果用户名已存在，则跳过注册流程
                                 }
                                 var cmd = new SQLiteCommand("INSERT INTO users (userid, username, password) VALUES (@userid, @username, @password)", User_db);
@@ -111,7 +139,7 @@ namespace chatserver
                                 cmd.ExecuteNonQuery();
                                 log.Info($"用户 {sginuser.username} 注册成功(id:{timedUlid})");
                                 var result = new SignResultData { type = "register", status = "succeed", message = "注册成功" };
-                                socket.Send(System.Text.Encoding.UTF8.GetBytes(JsonSerializer.Serialize(result)));
+                                SendWithPrefix(socket,System.Text.Encoding.UTF8.GetBytes(JsonSerializer.Serialize(result)));
                             }
                         }
                         else if (Type.type == "login")
@@ -123,21 +151,21 @@ namespace chatserver
                                 {
                                     log.Warn("用户名或密码不能为空");
                                     var emptyResult = new LoginResultData { type = "login", status = "error_-1", message = "用户名或密码不能为空" };
-                                    socket.Send(JsonSerializer.SerializeToUtf8Bytes(emptyResult));
+                                    SendWithPrefix(socket,JsonSerializer.SerializeToUtf8Bytes(emptyResult));
                                     continue;
                                 }
                                 if (loginData.username.Length < 2 || loginData.username.Length > 20)
                                 {
                                     log.Warn($"用户登录时 {loginData.username} 用户名长度不符合要求");
                                     var lengthResult = new LoginResultData { type = "login", status = "error_2", message = "用户名长度必须在2到20个字符之间" };
-                                    socket.Send(JsonSerializer.SerializeToUtf8Bytes(lengthResult));
+                                    SendWithPrefix(socket,JsonSerializer.SerializeToUtf8Bytes(lengthResult));
                                     continue;
                                 }
                                 if (loginData.password.Length > 20)
                                 {
                                     log.Warn($"用户登录时 {loginData.username} 密码长度不符合要求");
                                     var weakPwdResult = new LoginResultData { type = "login", status = "error_1", message = "密码长度不能超过20个字符" };
-                                    socket.Send(JsonSerializer.SerializeToUtf8Bytes(weakPwdResult));
+                                    SendWithPrefix(socket,JsonSerializer.SerializeToUtf8Bytes(weakPwdResult));
                                     continue;
                                 }
                                 var Authentication = UserAuthentication(loginData.username, loginData.password);
@@ -164,13 +192,13 @@ namespace chatserver
                                         username = loginData.username,
                                         userid = Authentication
                                     };
-                                    socket.Send(System.Text.Encoding.UTF8.GetBytes(JsonSerializer.Serialize(result)));
+                                    SendWithPrefix(socket,System.Text.Encoding.UTF8.GetBytes(JsonSerializer.Serialize(result)));
                                 }
                                 else
                                 {
                                     log.Warn($"用户 {loginData.username} 登录失败，用户名或密码错误");
                                     var result = new LoginResultData { type = "login", status = "error_0", message = "用户名或密码错误" };
-                                    socket.Send(System.Text.Encoding.UTF8.GetBytes(JsonSerializer.Serialize(result)));
+                                    SendWithPrefix(socket,System.Text.Encoding.UTF8.GetBytes(JsonSerializer.Serialize(result)));
                                 }
                             }
                         }
@@ -179,7 +207,7 @@ namespace chatserver
                             var chatData = JsonSerializer.Deserialize<ChatData>(message);
                             if (chatData != null && chatData.message != null)
                             {
-                                log.Info($"接收到聊天消息: {chatData.message}");
+                                log.Info($"接收到聊天消息(长度: {chatData.message.Length} )");
                                 if (Client.Count == 0)
                                 {
                                     log.Warn("没有客户端连接，取消发送消息。");
@@ -201,13 +229,13 @@ namespace chatserver
                                         msgtype = MessageType.Text,
                                         timestamp = DateTime.Now
                                     };
-                                    socket.Send(System.Text.Encoding.UTF8.GetBytes(JsonSerializer.Serialize(errorData)));
+                                    SendWithPrefix(socket,System.Text.Encoding.UTF8.GetBytes(JsonSerializer.Serialize(errorData)));
                                     continue;
                                 }
 
                                 List<Socket> clientsCopy;
                                 List<User> usersCopy;
-                                // 1. 获取集合快照
+                                // 获取集合快照
                                 lock (Client_lock)
                                 {
                                     clientsCopy = new List<Socket>(Client);  // 创建客户端列表副本
@@ -223,6 +251,31 @@ namespace chatserver
                                     status = "succeed",
                                     timestamp = DateTime.Now
                                 };
+                                Task.Run(() =>
+                                {
+                                    try
+                                    {
+                                        using (var dbConnection = new SQLiteConnection("Data Source=ServerUser.db;Version=3;"))
+                                        {
+                                            dbConnection.Open();
+                                            using (var cmd = new SQLiteCommand(@"
+                                                INSERT INTO messages (type, room_id, sender_id, receiver_id, content)
+                                                VALUES (@type, @room_id, @sender_id, @receiver_id, @content)", dbConnection))
+                                            {
+                                                cmd.Parameters.AddWithValue("@type", "group");
+                                                cmd.Parameters.AddWithValue("@room_id", "global");
+                                                cmd.Parameters.AddWithValue("@sender_id", chatData.userid);
+                                                cmd.Parameters.AddWithValue("@receiver_id", DBNull.Value);
+                                                cmd.Parameters.AddWithValue("@content", chatData.message);
+                                                cmd.ExecuteNonQuery();
+                                            }
+                                        }
+                                    }
+                                    catch (Exception ex)
+                                    {
+                                        log.Error($"存储消息到数据库失败: {ex.Message}");
+                                    }
+                                });
                                 foreach (var user in usersCopy)
                                 {
                                     // 查找匹配的客户端
@@ -234,7 +287,7 @@ namespace chatserver
                                         try
                                         {
                                             // ==== 修改：添加发送异常处理 ====
-                                            targetClient.Send(System.Text.Encoding.UTF8.GetBytes(JsonSerializer.Serialize(chatRegisterData)));
+                                            SendWithPrefix(targetClient,System.Text.Encoding.UTF8.GetBytes(JsonSerializer.Serialize(chatRegisterData)));
                                         }
                                         catch (SocketException ex)
                                         {
@@ -252,6 +305,59 @@ namespace chatserver
                                 log.Warn("接收到无效的聊天消息");
                             }
                         }
+                        else if (Type.type == "history")
+                        {
+                            var historyReq = JsonSerializer.Deserialize<HistoryRequest>(message);
+                            if (historyReq != null)
+                            {
+                                var response = new HistoryResponse();
+                                string query = "SELECT * FROM messages WHERE ";
+                                var parameters = new List<SQLiteParameter>();
+
+                                // 构建查询条件
+                                if (historyReq.chat_type == "group")
+                                {
+                                    query += "type = 'group' AND room_id = @room_id ";
+                                    parameters.Add(new SQLiteParameter("@room_id", historyReq.room_id ?? "global"));
+                                }
+                                //        else if (historyReq.chat_type == "private")
+                                //        {
+                                //            query += @"(type = 'private' AND 
+                                //((sender_id = @userid1 AND receiver_id = @userid2) OR 
+                                // (sender_id = @userid2 AND receiver_id = @userid1))) ";
+                                //            parameters.Add(new SQLiteParameter("@userid1", historyReq.sender_id));
+                                //            parameters.Add(new SQLiteParameter("@userid2", historyReq.receiver_id));
+                                //        }
+
+                                // 获取总消息数
+                                string countQuery = query.Replace("SELECT *", "SELECT COUNT(*)");
+                                using var countCmd = new SQLiteCommand(countQuery, User_db);
+                                countCmd.Parameters.AddRange(parameters.ToArray());
+                                response.total_count = Convert.ToInt32(countCmd.ExecuteScalar());
+
+                                // 获取分页消息
+                                query += "ORDER BY timestamp DESC LIMIT @count OFFSET @offset";
+                                using var cmd = new SQLiteCommand(query, User_db);
+                                cmd.Parameters.AddRange(parameters.ToArray());
+                                cmd.Parameters.AddWithValue("@count", historyReq.count);
+                                cmd.Parameters.AddWithValue("@offset", historyReq.offset);
+
+                                using var reader = cmd.ExecuteReader();
+                                while (reader.Read())
+                                {
+                                    response.history.Add(new ChatRegisterData
+                                    {
+                                        type = "chat",
+                                        userid = reader["sender_id"].ToString() ?? "Unid",
+                                        user = GetUsernameByUserId(reader["sender_id"].ToString() ?? "Unid"),
+                                        msgtype = MessageType.Text,
+                                        message = reader["content"].ToString(),
+                                        timestamp = Convert.ToDateTime(reader["timestamp"])
+                                    });
+                                }
+                                SendWithPrefix(socket,JsonSerializer.SerializeToUtf8Bytes(response));
+                            }
+                        }
                         else
                         {
                             log.Warn("未知的请求类型: " + Type.type);
@@ -285,6 +391,59 @@ namespace chatserver
             }
         }
         /// <summary>
+        /// 压缩数据
+        /// </summary>
+        /// <param name="data"></param>
+        /// <returns></returns>
+        private static byte[] Compress(byte[] data)
+        {
+            if (data.Length < 256)
+                return data;
+
+            using (var compressedStream = new MemoryStream())
+            {
+                using (var zipStream = new GZipStream(compressedStream, CompressionMode.Compress))
+                {
+                    zipStream.Write(data, 0, data.Length);
+                }
+                return compressedStream.ToArray();
+            }
+        }
+        /// <summary>
+        /// 解压缩数据
+        /// </summary>
+        /// <param name="compressedData"></param>
+        /// <returns></returns>
+        private static byte[] Decompress(byte[] compressedData)
+        {
+            if (compressedData.Length < 2 || compressedData[0] != 0x1F || compressedData[1] != 0x8B)
+                return compressedData;
+
+            using (var compressedStream = new MemoryStream(compressedData))
+            using (var zipStream = new GZipStream(compressedStream, CompressionMode.Decompress))
+            using (var resultStream = new MemoryStream())
+            {
+                zipStream.CopyTo(resultStream);
+                return resultStream.ToArray();
+            }
+        }
+        /// <summary>
+        /// 发送数据
+        /// </summary>
+        /// <param name="socket"></param>
+        /// <param name="data"></param>
+        private static void SendWithPrefix(Socket socket, byte[] data)
+        {
+            byte[] compressedData = Compress(data);
+            byte[] lengthPrefix = BitConverter.GetBytes(compressedData.Length);
+            byte[] fullMessage = new byte[lengthPrefix.Length + compressedData.Length];
+
+            Buffer.BlockCopy(lengthPrefix, 0, fullMessage, 0, lengthPrefix.Length);
+            Buffer.BlockCopy(compressedData, 0, fullMessage, lengthPrefix.Length, compressedData.Length);
+            log.Info($"发送数据(长度:{data.Length},压缩后长度:{lengthPrefix.Length},总体长度:{fullMessage.Length})");
+            socket.Send(fullMessage);
+        }
+        /// <summary>
         /// 查询User_db是否有相同用户名
         /// </summary>
         /// <param name="username"></param>
@@ -311,7 +470,7 @@ namespace chatserver
             return result != null ? result.ToString()! : string.Empty;
         }
         // 在ChatServer类中添加一个方法用于初始化users表
-        private static void EnsureUsersTableExists()
+        private static void InitializeTable()
         {
             using var cmd = new SQLiteCommand(@"
                 CREATE TABLE IF NOT EXISTS users (
@@ -320,12 +479,34 @@ namespace chatserver
                     password TEXT NOT NULL
                 )", User_db);
             cmd.ExecuteNonQuery();
+            // 新增消息表
+            using var cmd2 = new SQLiteCommand(@"
+                CREATE TABLE IF NOT EXISTS messages (
+                    id INTEGER PRIMARY KEY AUTOINCREMENT,
+                    type TEXT NOT NULL CHECK(type IN ('group', 'private')),
+                    room_id TEXT,
+                    sender_id TEXT NOT NULL REFERENCES users(userid),
+                    receiver_id TEXT REFERENCES users(userid),
+                    content TEXT NOT NULL,
+                    timestamp DATETIME DEFAULT CURRENT_TIMESTAMP
+                )", User_db);
+            cmd2.ExecuteNonQuery();
+
+            // 创建索引提高查询效率
+            using var cmd3 = new SQLiteCommand(@"
+                CREATE INDEX IF NOT EXISTS idx_messages_timestamp 
+                ON messages (timestamp DESC)", User_db);
+            cmd3.ExecuteNonQuery();
+            using var cmd4 = new SQLiteCommand(@"
+                CREATE INDEX IF NOT EXISTS idx_messages_room 
+                ON messages (room_id, timestamp DESC)", User_db);
+            cmd4.ExecuteNonQuery();
         }
         /// <summary>
         /// 根据userid查询对应的用户名
         /// </summary>
         /// <param name="userid"></param>
-        /// <returns>用户名，如果不存在则返回</returns>
+        /// <returns>用户名，如果userid为空或为"Unid"，返回默认用户名"Unnamed"</returns>
         static string GetUsernameByUserId(string userid)
         {
             if (string.IsNullOrEmpty(userid) || userid == "Unid")