diff --git a/插件库/Lskj.Main/Hosting/LegacyApplicationHost.cs b/插件库/Lskj.Main/Hosting/LegacyApplicationHost.cs
index 402f90f..82a9db0 100644
--- a/插件库/Lskj.Main/Hosting/LegacyApplicationHost.cs
+++ b/插件库/Lskj.Main/Hosting/LegacyApplicationHost.cs
@@ -43,7 +43,7 @@ namespace Lskj.Main.Hosting
     /// 向外部 WPF 登录页提供旧账套、用户、认证和会话状态写入能力。
     /// 该类型不创建 WinForms 控件，也不引用 WPF。
     /// </summary>
-    public sealed class LegacyLoginRuntime
+    public sealed partial class LegacyLoginRuntime
     {
         private DataTable _ledgerTable;
 
diff --git a/插件库/Lskj.Main/Hosting/LegacyLoginRuntime.ConnectionSettings.cs b/插件库/Lskj.Main/Hosting/LegacyLoginRuntime.ConnectionSettings.cs
new file mode 100644
index 0000000..8856719
--- /dev/null
+++ b/插件库/Lskj.Main/Hosting/LegacyLoginRuntime.ConnectionSettings.cs
@@ -0,0 +1,595 @@
+using System;
+using System.Collections.Generic;
+using System.Data;
+using System.IO;
+using System.Net;
+using System.Text;
+using Microsoft.Win32;
+using Lskj.Business;
+using Lskj.Business.Impl;
+using Lskj.Control.Model;
+using Lskj.Core;
+using Lskj.Main.Model;
+using Lskj.Model;
+using Lskj.Util;
+
+namespace Lskj.Main.Hosting
+{
+    public sealed partial class LegacyLoginRuntime
+    {
+        private const string RegistryFilePath = @"AA_LS_Erp V2.0\File";
+        private const string SystemResourcesIniName = "SystemResources.ini";
+        private const string SystemResourcesSection = "SystemResources";
+        private const string DirectHistoryPrefix = "DownloadAESStr_";
+        private const string DirectLastHostKey = "LocalLastIP";
+        private const string DirectLastPortKey = "LocalLastPort";
+        private const string DirectLastNameKey = "LocalLastPortName";
+        private const string ConnectionModeKey = "FrmConfigFlag";
+        private const int DirectRequestTimeoutMilliseconds = 5000;
+
+        public DataSet LoadConnectionSettings()
+        {
+            var result = new DataSet("LoginConnectionSettings");
+            DataTable settings = CreateSettingsTable();
+            DataTable savedConnections = CreateSavedConnectionsTable();
+
+            string directHost = IniHelper.Read(
+                SystemResourcesIniName,
+                DirectLastHostKey);
+            string directPort = IniHelper.Read(
+                SystemResourcesIniName,
+                DirectLastPortKey);
+            string directName = IniHelper.Read(
+                SystemResourcesIniName,
+                DirectLastNameKey);
+            bool directMode = string.Equals(
+                IniHelper.Read(SystemResourcesIniName, ConnectionModeKey),
+                "1",
+                StringComparison.Ordinal);
+
+            settings.Rows.Add(
+                directMode ? "Direct" : "Database",
+                ReadRegistryValue("ServerName"),
+                ReadRegistryValue("datastr"),
+                directHost,
+                directPort,
+                directName);
+
+            Dictionary<string, string> entries = IniHelper.GetSectionKeys(
+                SystemResourcesIniName,
+                SystemResourcesSection);
+            foreach (KeyValuePair<string, string> entry in entries)
+            {
+                if (!entry.Key.StartsWith(
+                    DirectHistoryPrefix,
+                    StringComparison.OrdinalIgnoreCase))
+                {
+                    continue;
+                }
+
+                string endpoint = entry.Key.Substring(
+                    DirectHistoryPrefix.Length);
+                string host;
+                int port;
+                if (!TrySplitEndpoint(endpoint, out host, out port))
+                    continue;
+
+                string displayName = ReadHistoryDisplayName(entry.Value);
+                if (string.IsNullOrWhiteSpace(displayName))
+                    continue;
+
+                savedConnections.Rows.Add(
+                    entry.Key,
+                    displayName,
+                    host,
+                    port);
+            }
+
+            result.Tables.Add(settings);
+            result.Tables.Add(savedConnections);
+            return result;
+        }
+
+        public string ApplyDatabaseConnection(
+            string serverName,
+            string databaseName)
+        {
+            try
+            {
+                ConnectionCandidate candidate = CreateDatabaseCandidate(
+                    serverName,
+                    databaseName);
+                return ApplyConnection(
+                    candidate,
+                    delegate { CommitDatabaseConnection(); });
+            }
+            catch (Exception exception)
+            {
+                LogSanitized(exception);
+                return ToSafeConnectionError(exception);
+            }
+        }
+
+        public string ApplyDirectConnection(
+            string host,
+            int port,
+            string accountBookName)
+        {
+            try
+            {
+                Uri resourceUri = BuildDirectResourceUri(host, port);
+                string encryptedPayload = DownloadDirectPayload(resourceUri);
+                string decryptedPayload = AESUtil.Decrypt(encryptedPayload);
+                string[] parts = ParseDirectPayload(decryptedPayload);
+                ConnectionCandidate candidate = CreateDirectCandidate(
+                    parts,
+                    host,
+                    port,
+                    accountBookName,
+                    encryptedPayload);
+                return ApplyConnection(
+                    candidate,
+                    delegate { CommitDirectConnection(candidate); });
+            }
+            catch (Exception exception)
+            {
+                LogSanitized(exception);
+                return ToSafeConnectionError(exception);
+            }
+        }
+
+        private string ApplyConnection(
+            ConnectionCandidate candidate,
+            Action commit)
+        {
+            LegacyConnectionStateSnapshot snapshot =
+                LegacyConnectionStateSnapshot.Capture(this);
+            try
+            {
+                ApplyCandidate(candidate);
+                ValidateDatabase(candidate);
+                ValidateDelphi(candidate);
+                SystemInfo.RefreshSystemParam();
+                commit();
+
+                _ledgerTable = null;
+                SelectedLedgerName = candidate.AccountBookName;
+                ERPInfo.Instance.AccountBook = candidate.AccountBookName;
+                return string.Empty;
+            }
+            catch (Exception exception)
+            {
+                snapshot.Restore(this);
+                LogSanitized(exception);
+                return ToSafeConnectionError(exception);
+            }
+        }
+
+        private static ConnectionCandidate CreateDatabaseCandidate(
+            string serverName,
+            string databaseName)
+        {
+            serverName = (serverName ?? string.Empty).Trim();
+            databaseName = (databaseName ?? string.Empty).Trim();
+            if (string.IsNullOrWhiteSpace(serverName))
+                throw new ArgumentException("请输入数据库服务器地址。");
+            if (string.IsNullOrWhiteSpace(databaseName))
+                throw new ArgumentException("请输入数据库名称。");
+
+            return new ConnectionCandidate
+            {
+                ServerName = serverName,
+                DatabaseName = databaseName,
+                AccountBookName = DBConfig.Instance.DataBook ?? string.Empty,
+                ServerType = DBConfig.Instance.ServerType ?? "SqlServer",
+                ConnectionTemplate = string.Empty,
+                DelphiConnectionTemplate = string.Empty
+            };
+        }
+
+        private static ConnectionCandidate CreateDirectCandidate(
+            string[] parts,
+            string host,
+            int port,
+            string accountBookName,
+            string encryptedPayload)
+        {
+            accountBookName = (accountBookName ?? string.Empty).Trim();
+            if (string.IsNullOrWhiteSpace(accountBookName))
+                throw new ArgumentException("请输入直连账套名称。");
+
+            string connectionTemplate =
+                "Server={0};Database={1};Persist Security Info=True;" +
+                "User ID=" + parts[2] + ";Password=" + parts[3] + ";" +
+                "Connection Timeout=5;MultipleActiveResultSets=true";
+            string delphiTemplate =
+                "Provider=SQLOLEDB.1;Server={0};Database={1};" +
+                "Persist Security Info=True;User ID=" + parts[2] +
+                ";Password=" + parts[3] + ";Connection Timeout=5";
+
+            return new ConnectionCandidate
+            {
+                ServerName = parts[0],
+                DatabaseName = parts[1],
+                AccountBookName = accountBookName,
+                ServerType = DBConfig.Instance.ServerType ?? "SqlServer",
+                ConnectionTemplate = AESUtil.Encrypt(connectionTemplate),
+                DelphiConnectionTemplate = AESUtil.Encrypt(delphiTemplate),
+                DirectHost = (host ?? string.Empty).Trim().TrimEnd('/'),
+                DirectPort = port,
+                DirectEncryptedPayload = encryptedPayload
+            };
+        }
+
+        private static void ApplyCandidate(ConnectionCandidate candidate)
+        {
+            DBConfig.Instance.ServerName = candidate.ServerName;
+            DBConfig.Instance.DataBase = candidate.DatabaseName;
+            DBConfig.Instance.DataBook = candidate.AccountBookName;
+            DBConfig.Instance.ServerType = candidate.ServerType;
+            DBConfig.Instance.Connection = candidate.ConnectionTemplate;
+            DBConfig.Instance.dephiConnection =
+                candidate.DelphiConnectionTemplate;
+        }
+
+        private static void ValidateDatabase(ConnectionCandidate candidate)
+        {
+            if (!DBConfig.Instance.CreateConnection(
+                candidate.ConnectionTemplate))
+            {
+                throw new LegacyConnectionSettingsException(
+                    "无法连接数据库，请检查服务器和数据库配置。");
+            }
+        }
+
+        private static void ValidateDelphi(ConnectionCandidate candidate)
+        {
+            if (string.Equals(
+                candidate.ServerType,
+                "达梦数据库",
+                StringComparison.Ordinal))
+            {
+                return;
+            }
+
+            string connection = DBConfig.Instance.GetDelphiConnection(
+                candidate.DelphiConnectionTemplate);
+            if (DelphiHelper.Delphi_Init(new StringBuilder(connection)) == 0)
+            {
+                throw new LegacyConnectionSettingsException(
+                    "数据库已连接，但 Delphi 组件初始化失败。");
+            }
+        }
+
+        private static void CommitDatabaseConnection()
+        {
+            DBConfig.Instance.WriteConfig();
+            IniHelper.Write(
+                SystemResourcesIniName,
+                ConnectionModeKey,
+                "0");
+        }
+
+        private static void CommitDirectConnection(
+            ConnectionCandidate candidate)
+        {
+            string endpoint = candidate.DirectHost + ":" +
+                candidate.DirectPort;
+            string historyValue = candidate.AccountBookName + "^" +
+                candidate.DirectEncryptedPayload;
+
+            IniHelper.Write(
+                SystemResourcesIniName,
+                DirectHistoryPrefix + endpoint,
+                historyValue);
+            IniHelper.Write(
+                SystemResourcesIniName,
+                DirectLastHostKey,
+                candidate.DirectHost);
+            IniHelper.Write(
+                SystemResourcesIniName,
+                DirectLastPortKey,
+                candidate.DirectPort.ToString());
+            IniHelper.Write(
+                SystemResourcesIniName,
+                DirectLastNameKey,
+                candidate.AccountBookName);
+            IniHelper.Write(
+                SystemResourcesIniName,
+                ConnectionModeKey,
+                "1");
+
+            DBConfig.Instance.WriteConfig(
+                DirectLastHostKey,
+                candidate.DirectHost);
+            DBConfig.Instance.WriteConfig(
+                DirectLastPortKey,
+                candidate.DirectPort.ToString());
+            DBConfig.Instance.WriteConfig(
+                DirectLastNameKey,
+                candidate.AccountBookName);
+        }
+
+        private static Uri BuildDirectResourceUri(string host, int port)
+        {
+            host = (host ?? string.Empty).Trim();
+            if (string.IsNullOrWhiteSpace(host))
+                throw new ArgumentException("请输入直连服务器地址。");
+            if (port < 1 || port > 65535)
+                throw new ArgumentOutOfRangeException(
+                    "port",
+                    "直连端口必须介于 1 和 65535 之间。");
+
+            if (!host.StartsWith("http://", StringComparison.OrdinalIgnoreCase) &&
+                !host.StartsWith("https://", StringComparison.OrdinalIgnoreCase))
+            {
+                host = "http://" + host;
+            }
+
+            Uri baseUri;
+            if (!Uri.TryCreate(host, UriKind.Absolute, out baseUri) ||
+                (baseUri.Scheme != Uri.UriSchemeHttp &&
+                 baseUri.Scheme != Uri.UriSchemeHttps))
+            {
+                throw new ArgumentException("直连服务器地址格式无效。");
+            }
+
+            var builder = new UriBuilder(baseUri)
+            {
+                Port = port,
+                Path = "/SystemResources.txt",
+                Query = string.Empty,
+                Fragment = string.Empty
+            };
+            return builder.Uri;
+        }
+
+        private static string DownloadDirectPayload(Uri resourceUri)
+        {
+            var request = (HttpWebRequest)WebRequest.Create(resourceUri);
+            request.Method = "GET";
+            request.Timeout = DirectRequestTimeoutMilliseconds;
+            request.ReadWriteTimeout = DirectRequestTimeoutMilliseconds;
+
+            using (var response = (HttpWebResponse)request.GetResponse())
+            using (Stream stream = response.GetResponseStream())
+            {
+                if (stream == null)
+                {
+                    throw new InvalidDataException(
+                        "直连服务器未返回连接配置。");
+                }
+
+                using (var reader = new StreamReader(
+                    stream,
+                    Encoding.UTF8,
+                    true))
+                {
+                    string payload = reader.ReadToEnd().Trim();
+                    if (string.IsNullOrWhiteSpace(payload))
+                    {
+                        throw new InvalidDataException(
+                            "直连服务器返回的连接配置为空。");
+                    }
+
+                    return payload;
+                }
+            }
+        }
+
+        private static string[] ParseDirectPayload(string decryptedPayload)
+        {
+            string[] parts = (decryptedPayload ?? string.Empty).Split('^');
+            if (parts.Length != 5)
+            {
+                throw new InvalidDataException(
+                    "直连服务器返回的连接配置格式无效。");
+            }
+
+            for (int index = 0; index < parts.Length; index++)
+            {
+                parts[index] = (parts[index] ?? string.Empty).Trim();
+                if (string.IsNullOrWhiteSpace(parts[index]))
+                {
+                    throw new InvalidDataException(
+                        "直连服务器返回的连接配置不完整。");
+                }
+            }
+
+            return parts;
+        }
+
+        private static string ToSafeConnectionError(Exception exception)
+        {
+            if (exception is ArgumentException ||
+                exception is InvalidDataException ||
+                exception is LegacyConnectionSettingsException)
+            {
+                return exception.Message;
+            }
+            if (exception is WebException)
+            {
+                return "无法读取直连配置，请检查地址、端口和网络连接。";
+            }
+
+            return "连接设置失败，请检查配置和网络连接。";
+        }
+
+        private static void LogSanitized(Exception exception)
+        {
+            string exceptionType = exception == null
+                ? "Unknown"
+                : exception.GetType().FullName;
+            LogHelper.Instance.WriteLog(
+                "WPF 登录连接设置失败。异常类型：" + exceptionType);
+        }
+
+        private static DataTable CreateSettingsTable()
+        {
+            var table = new DataTable("Settings");
+            table.Columns.Add("Mode", typeof(string));
+            table.Columns.Add("ServerName", typeof(string));
+            table.Columns.Add("DatabaseName", typeof(string));
+            table.Columns.Add("DirectHost", typeof(string));
+            table.Columns.Add("DirectPort", typeof(string));
+            table.Columns.Add("DirectAccountBookName", typeof(string));
+            return table;
+        }
+
+        private static DataTable CreateSavedConnectionsTable()
+        {
+            var table = new DataTable("SavedDirectConnections");
+            table.Columns.Add("Key", typeof(string));
+            table.Columns.Add("DisplayName", typeof(string));
+            table.Columns.Add("Host", typeof(string));
+            table.Columns.Add("Port", typeof(int));
+            return table;
+        }
+
+        private static string ReadRegistryValue(string valueName)
+        {
+            try
+            {
+                using (RegistryKey key = Registry.CurrentUser.OpenSubKey(
+                    RegistryFilePath,
+                    false))
+                {
+                    object value = key == null
+                        ? null
+                        : key.GetValue(valueName, string.Empty);
+                    return value == null ? string.Empty : value.ToString();
+                }
+            }
+            catch
+            {
+                return string.Empty;
+            }
+        }
+
+        private static bool TrySplitEndpoint(
+            string endpoint,
+            out string host,
+            out int port)
+        {
+            host = string.Empty;
+            port = 0;
+            if (string.IsNullOrWhiteSpace(endpoint))
+                return false;
+
+            int separatorIndex = endpoint.LastIndexOf(':');
+            if (separatorIndex <= 0 ||
+                separatorIndex >= endpoint.Length - 1)
+            {
+                return false;
+            }
+
+            host = endpoint.Substring(0, separatorIndex).Trim();
+            return !string.IsNullOrWhiteSpace(host) &&
+                int.TryParse(endpoint.Substring(separatorIndex + 1), out port) &&
+                port >= 1 &&
+                port <= 65535;
+        }
+
+        private static string ReadHistoryDisplayName(string value)
+        {
+            if (string.IsNullOrWhiteSpace(value))
+                return string.Empty;
+
+            int separatorIndex = value.IndexOf('^');
+            return separatorIndex < 0
+                ? string.Empty
+                : value.Substring(0, separatorIndex).Trim();
+        }
+
+        private sealed class ConnectionCandidate
+        {
+            public string ServerName;
+            public string DatabaseName;
+            public string AccountBookName;
+            public string ServerType;
+            public string ConnectionTemplate;
+            public string DelphiConnectionTemplate;
+            public string DirectHost;
+            public int DirectPort;
+            public string DirectEncryptedPayload;
+        }
+
+        private sealed class LegacyConnectionStateSnapshot
+        {
+            private string _serverName;
+            private string _databaseName;
+            private string _dataBook;
+            private string _loginName;
+            private string _serverType;
+            private string _connectionTemplate;
+            private string _delphiConnectionTemplate;
+            private string _selectedLedgerName;
+            private string _accountBook;
+
+            public static LegacyConnectionStateSnapshot Capture(
+                LegacyLoginRuntime runtime)
+            {
+                return new LegacyConnectionStateSnapshot
+                {
+                    _serverName = DBConfig.Instance.ServerName,
+                    _databaseName = DBConfig.Instance.DataBase,
+                    _dataBook = DBConfig.Instance.DataBook,
+                    _loginName = DBConfig.Instance.LoginName,
+                    _serverType = DBConfig.Instance.ServerType,
+                    _connectionTemplate = DBConfig.Instance.Connection,
+                    _delphiConnectionTemplate =
+                        DBConfig.Instance.dephiConnection,
+                    _selectedLedgerName = runtime.SelectedLedgerName,
+                    _accountBook = ERPInfo.Instance.AccountBook
+                };
+            }
+
+            public void Restore(LegacyLoginRuntime runtime)
+            {
+                DBConfig.Instance.ServerName = _serverName;
+                DBConfig.Instance.DataBase = _databaseName;
+                DBConfig.Instance.DataBook = _dataBook;
+                DBConfig.Instance.LoginName = _loginName;
+                DBConfig.Instance.ServerType = _serverType;
+                DBConfig.Instance.Connection = _connectionTemplate;
+                DBConfig.Instance.dephiConnection =
+                    _delphiConnectionTemplate;
+                runtime.SelectedLedgerName = _selectedLedgerName;
+                runtime._ledgerTable = null;
+                ERPInfo.Instance.AccountBook = _accountBook;
+
+                try
+                {
+                    if (!string.IsNullOrWhiteSpace(_serverName) &&
+                        !string.IsNullOrWhiteSpace(_databaseName))
+                    {
+                        DBConfig.Instance.CreateConnection(
+                            _connectionTemplate);
+                        if (!string.Equals(
+                            _serverType,
+                            "达梦数据库",
+                            StringComparison.Ordinal))
+                        {
+                            DelphiHelper.Delphi_Init(new StringBuilder(
+                                DBConfig.Instance.GetDelphiConnection(
+                                    _delphiConnectionTemplate)));
+                        }
+                        SystemInfo.RefreshSystemParam();
+                    }
+                }
+                catch (Exception restoreException)
+                {
+                    LogSanitized(restoreException);
+                }
+            }
+        }
+
+        private sealed class LegacyConnectionSettingsException : Exception
+        {
+            public LegacyConnectionSettingsException(string message)
+                : base(message)
+            {
+            }
+        }
+    }
+}
diff --git a/插件库/Lskj.Main/Lskj.Main.csproj b/插件库/Lskj.Main/Lskj.Main.csproj
index 355288c..896046f 100644
--- a/插件库/Lskj.Main/Lskj.Main.csproj
+++ b/插件库/Lskj.Main/Lskj.Main.csproj
@@ -278,6 +278,7 @@
     <Compile Include="Model\winApi.cs" />
     <Compile Include="Hosting\IExternalMainShell.cs" />
     <Compile Include="Hosting\LegacyApplicationHost.cs" />
+    <Compile Include="Hosting\LegacyLoginRuntime.ConnectionSettings.cs" />
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <EmbeddedResource Include="Control\AwaitScreenControl.resx">