SQLExpress winform 备份问题。

这个是连接字符串：Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database\Securitybilling.mdf;Integrated Security=True;User Instance=True"
using System;using System.Data.SqlClient;using Microsoft.SqlServer.Management.Smo;using Microsoft.SqlServer.Management.Common;namespace CreateRANU{    class Program    {        static void Main(string[] args)        {            string strCon = "";            BackupDatabase(strCon);            RestoreBackup(strCon);        }        public static void BackupDatabase(string sConnect)        {            string dbName;            using (SqlConnection cnn = new SqlConnection(sConnect))            {                cnn.Open();                dbName = cnn.Database.ToString();                ServerConnection sc = new ServerConnection(cnn);                Server sv = new Server(sc);                // Check that I'm connected to the user instance                Console.WriteLine(sv.InstanceName.ToString());                // Create backup device item for the backup                BackupDeviceItem bdi = new BackupDeviceItem(@"C:\AppDataBackup\SampleBackup.bak", DeviceType.File);                // Create the backup informaton                Backup bk = new Backup();                bk.Devices.Add(bdi);                 bk.Action = BackupActionType.Database;                bk.BackupSetDescription = "SQL Express is a great product!";                bk.BackupSetName = "SampleBackupSet";                bk.Database = dbName;                bk.ExpirationDate = new DateTime(2007, 5, 1);                bk.LogTruncation = BackupTruncateLogType.Truncate;                // Run the backup                bk.SqlBackup(sv);                Console.WriteLine("Your backup is complete.");            }        }        public static void RestoreBackup(string sConnect)        {             string dbName;            using (SqlConnection cnn = new SqlConnection(sConnect))            {                cnn.Open();                dbName = cnn.Database.ToString();                cnn.ChangeDatabase("master");                ServerConnection sc = new ServerConnection(cnn);                Server sv = new Server(sc);                // Check that I'm connected to the user instance                Console.WriteLine(sv.InstanceName.ToString());                // Create backup device item for the backup                BackupDeviceItem bdi = new BackupDeviceItem(@"C:\AppDataBackup\SampleBackup.bak", DeviceType.File);                // Create the restore object                Restore resDB = new Restore();                resDB.Devices.Add(bdi);                resDB.NoRecovery = false;                resDB.ReplaceDatabase = true;                resDB.Database = dbName;                // Restore the database                resDB.SqlRestore(sv);                Console.WriteLine("Your database has been restored.");              }                }                public static void CreateDatabase()        {            using (SqlConnection cn = new SqlConnection(@"Data Source=.\SQLEXPRESS;Integrated Security=True;User Instance=True;Connection Timeout=60"))            {                cn.Open();                SqlCommand cmd = new SqlCommand("CREATE DATABASE forumTest1", cn);                cmd.ExecuteNonQuery();                SqlConnection cn2 = new SqlConnection(@"Data Source=.\SQLEXPRESS;Integrated Security=True;AttachDbFilename=|DataDirectory|\forumTest1.mdf;User Instance=True;Connection Timeout=60");                cn2.Open();            }                }    }}报还原 对于 服务器“\\.\pipe\0768A80B-EC64-44\tsql\query”失败。请各位大侠帮帮我