//获取配置文件中sql数据库名 
            string dbName = System.Configuration.ConfigurationManager.AppSettings["dbName"];
            string name = fileName;//dbName + DateTime.Now.ToString("yyyyMMddHHmmss");
            string procname;
            string sql;
            //创建连接对象 
            SqlConnection conn = new SqlConnection(Public.ConnectionString);
            conn.Open(); //打开数据库连接
            //删除逻辑备份设备，但不会删掉备份的数据库文件 
            procname = "sp_dropdevice";
            SqlCommand sqlcmd1 = new SqlCommand(procname, conn);
            sqlcmd1.CommandType = CommandType.StoredProcedure;
            SqlParameter sqlpar = new SqlParameter();
            sqlpar = sqlcmd1.Parameters.Add("@logicalname", SqlDbType.VarChar, 20);
            sqlpar.Direction = ParameterDirection.Input;
            sqlpar.Value = dbName;
            sqlcmd1.ExecuteNonQuery();
            //创建逻辑备份设备 
            procname = "sp_addumpdevice";
            SqlCommand sqlcmd2 = new SqlCommand(procname, conn);
            sqlcmd2.CommandType = CommandType.StoredProcedure;
            sqlpar = sqlcmd2.Parameters.Add("@devtype", SqlDbType.VarChar, 20);
            sqlpar.Direction = ParameterDirection.Input;
            sqlpar.Value = "disk";
            sqlpar = sqlcmd2.Parameters.Add("@logicalname", SqlDbType.VarChar, 20);//逻辑设备名 
            sqlpar.Direction = ParameterDirection.Input;
            sqlpar.Value = dbName;
            sqlpar = sqlcmd2.Parameters.Add("@physicalname", SqlDbType.NVarChar, 260);//物理设备名 
            sqlpar.Direction = ParameterDirection.Input;
            sqlpar.Value = backupFolder + name + ".bak";
            try
            {
                int i = sqlcmd2.ExecuteNonQuery();
            }
            catch (Exception err)
            {
                string str = err.Message;
            }
            //备份数据库到指定的数据库文件(完全备份) 
            sql = "BACKUP DATABASE " + dbName + " TO " + dbName + " WITH INIT";
            SqlCommand sqlcmd3 = new SqlCommand(sql, conn);
            sqlcmd3.CommandType = CommandType.Text;
            try
            {
                sqlcmd3.ExecuteNonQuery();
            }
            catch (Exception err)
            {
                string str = err.Message;
                conn.Close();
                return false;
            }
            conn.Close();//关闭数据库连接 
            return true;