services.cs

微软的行业应用解决方案实例！非常优秀的Windows Mobile开发案例

                //Release Command object resources
                _cmd.Dispose();
            }
        }


        /// <summary>
        /// Verify a user's login credentials to either
        /// grant or deny access to the system
        /// </summary>
        /// <param name="userName"></param>
        /// <param name="password"></param>
        /// <returns></returns>
        public static bool VerifyCredentials(string userName, string password)
        {
            SqlCeCommand _cmd = null;

            try
            {
                //Create a Command object
                _cmd = new SqlCeCommand();
                //Set the SQL statement
                _cmd.CommandText = "SELECT COUNT(*) FROM Employees WHERE UserName = @UserName AND Password = @Password";
                //Add Paramters plus values
                _cmd.Parameters.AddWithValue("@UserName", userName);
                _cmd.Parameters.AddWithValue("@Password", password);

                //Retrieve number of users that match the supplied credentials
                int count = (int)Data.Database.ReadSingleValue(_cmd);

                //If none match, return false and deny access
                if (count == 0)
                {
                    return false;
                }
                else
                {
                    return true;
                }
            }
            finally
            {
                //Release Command object resources
                _cmd.Dispose();
            }
        }


        /// <summary>
        /// Create a new Order and associated OrderDetails
        /// </summary>
        /// <param name="customerId"></param>
        /// <param name="deliveryDate"></param>
        /// <param name="orderState"></param>
        /// <param name="orderItems"></param>
        public static void CreateOrder(int customerId, string deliveryDate, int orderState, ListView.ListViewItemCollection orderItems)
        {
            SqlCeCommand _cmd = null;

            try
            {
                //Create a Command object
                _cmd = new SqlCeCommand();
                //Set the SQL statement
                _cmd.CommandText = "INSERT INTO Orders (CustomerId, DeliveryDate, OrderState) VALUES (@CustomerId, @DeliveryDate, @OrderState)";
                //Add Paramters plus values
                _cmd.Parameters.AddWithValue("@CustomerId", customerId);
                _cmd.Parameters.AddWithValue("@DeliveryDate", deliveryDate);
                _cmd.Parameters.AddWithValue("@OrderState", orderState);

                //Insert new Order into database
                Data.Database.InsertUpdateDelete(_cmd);

                //Set the SQL statement
                _cmd.CommandText = "SELECT @@IDENTITY";
                //Retrieve value of Identity column that was just incremented
                int _identity = Convert.ToInt32(Data.Database.ReadSingleValue(_cmd));

                //Iterate through collection
                foreach (ListViewItem item in orderItems)
                {
                    //Set the SQL statement
                    _cmd.CommandText = "INSERT INTO OrderDetails (OrderId, InventoryId, Quantity) VALUES (@OrderId, @InventoryId, @Quantity)";
                    _cmd.Parameters.Clear();
                    //Add Paramters plus values
                    _cmd.Parameters.AddWithValue("@OrderId", _identity);
                    _cmd.Parameters.AddWithValue("@InventoryId", int.Parse(item.SubItems[2].Text));
                    _cmd.Parameters.AddWithValue("@Quantity", int.Parse(item.SubItems[0].Text));

                    //Insert OrderDetails data
                    Data.Database.InsertUpdateDelete(_cmd);
                }
            }
            finally
            {
                //Release Command object resources
                _cmd.Dispose();
            }
        }


        /// <summary>
        /// Update the current state of an order 
        /// </summary>
        /// <param name="orderId"></param>
        /// <param name="orderState"></param>
        public static void UpdateOrderState(int orderId, OrderState orderState)
        {
            SqlCeCommand _cmd = null;

            try
            {
                //Update OrderState value
                int _orderState = (int)orderState;
                //Create a Command object
                _cmd = new SqlCeCommand();
                //Set the SQL statement
                _cmd.CommandText = "UPDATE Orders SET OrderState = @OrderState WHERE OrderId = @OrderId";
                //Add Paramters plus values
                _cmd.Parameters.AddWithValue("@OrderState", _orderState);
                _cmd.Parameters.AddWithValue("@OrderId", orderId);

                //Update the order state based on the passed-in enum
                Data.Database.InsertUpdateDelete(_cmd);
            }
            finally
            {
                //Release Command object resources
                _cmd.Dispose();
            }
        }


        /// <summary>
        /// Update the amount of Inventory items in stock
        /// </summary>
        /// <param name="inventoryId"></param>
        /// <param name="inStock"></param>
        public static void UpdateInStockAmount(int inventoryId, int inStock)
        {
            SqlCeCommand _cmd = null;

            try
            {
                //Create a Command object
                _cmd = new SqlCeCommand();
                //Set the SQL statement
                _cmd.CommandText = "UPDATE Inventory SET InStock = @InStock WHERE InventoryId = @InventoryId";
                //Add Paramters plus values
                _cmd.Parameters.AddWithValue("@InStock", inStock);
                _cmd.Parameters.AddWithValue("@InventoryId", inventoryId);

                //Update the InStock amount based on the InventoryId
                Data.Database.InsertUpdateDelete(_cmd);
            }
            finally
            {
                //Release Command object resources
                _cmd.Dispose();
            }
        }


        /// <summary>
        /// Get the price of an Inventory item
        /// </summary>
        /// <param name="inventoryId"></param>
        /// <returns></returns>
        public static decimal GetPrice(int inventoryId)
        {
            SqlCeCommand _cmd = null;

            try
            {
                //Create a Command object
                _cmd = new SqlCeCommand();
                //Set the SQL statement
                _cmd.CommandText = "SELECT Price from Inventory WHERE InventoryId = @InventoryId";
                //Add Paramters plus values
                _cmd.Parameters.AddWithValue("@InventoryId", inventoryId);

                //Retrieve the price based on the InventoryId
                return (decimal)Data.Database.ReadSingleValue(_cmd);
            }
            finally
            {
                //Release Command object resources
                _cmd.Dispose();
            }
        }


        /// <summary>
        /// Retrieve a route map in Bitmap form
        /// </summary>
        /// <param name="height"></param>
        /// <param name="width"></param>
        /// <param name="address"></param>
        /// <param name="city"></param>
        /// <param name="state"></param>
        /// <returns></returns>
        public static Bitmap GetRouteMap(int height, int width, string address, string city, string state)
        {
            //Pass the address and PictureBox dimensions to retrieve a map bitmap
            return Data.NetAccess.CallMapPoint(height, width, address, city, state);
        }

        
        /// <summary>
        /// Save the signature Gif file to a database Image column
        /// </summary>
        /// <param name="signaturePath"></param>
        /// <param name="orderId"></param>
        public static void SaveGifToDatabase(string signaturePath, int orderId)
        {
            SqlCeCommand _cmd = null;
            FileStream fs = null;
            byte[] imageData;

            try
            {
                //Open Gif file
                fs = File.Open(signaturePath, FileMode.Open);

                //Create byte array equal to the size of the Gif file
                imageData = new byte[fs.Length];

                //Write Gif image data to the byte array
                fs.Read(imageData, 0, imageData.Length);

                //Create a Command object
                _cmd = new SqlCeCommand();
                //Set the SQL statement
                _cmd.CommandText = "UPDATE Orders SET Signature = @Signature WHERE OrderId = @OrderId";
                //Add Paramters plus values
                _cmd.Parameters.AddWithValue("@Signature", imageData);
                _cmd.Parameters.AddWithValue("@OrderId", orderId);

                //Add signature byte array to the Orders table
                Data.Database.InsertUpdateDelete(_cmd);
            }
            finally
            {
                //Close the FileStream object
                fs.Close();
                //Release Command object resources
                _cmd.Dispose();
            }
        }
                       

        /// <summary>
        /// Pass in a string seed to return a unique 
        /// Device Id in the form of a byte array
        /// </summary>
        /// <param name="appString"></param>
        /// <returns></returns>
        private static byte[] getDeviceID(string appString)
        {
            //Create a byte array based on the length of the appString
            byte[] _appData = new byte[appString.Length];
            //Iterate through the appString
            for (int _count = 0; _count < appString.Length; _count++)
            {
                //Add appString bytes to _appData byte array
                _appData[_count] = (byte)appString[_count];
            }
            int _appDataSize = _appData.Length;
            byte[] _deviceOutput = new byte[20];
            uint _sizeOut = 20;
            //Call the GetDeviceUniqueID function
            GetDeviceUniqueID(_appData, _appDataSize, 1, _deviceOutput, out _sizeOut);
            return _deviceOutput;
        }


        #region P/Invokes


        [DllImport("coredll.dll")]
        private extern static int GetDeviceUniqueID([In, Out] byte[] appdata,
                                                    int cbApplictionData,
                                                    int dwDeviceIDVersion,
                                                    [In, Out] byte[] deviceIDOuput,
                                                    out uint pcbDeviceIDOutput);


        public class MEMORYSTATUS
        {
            public uint dwLength;
            public uint dwMemoryLoad;
            public uint dwTotalPhys;
            public uint dwAvailPhys;
            public uint dwTotalPageFile;
            public uint dwAvailPageFile;
            public uint dwTotalVirtual;
            public uint dwAvailVirtual;
        }

        [DllImport("CoreDll.dll")]
        public static extern void GlobalMemoryStatus
        (
          MEMORYSTATUS lpBuffer
        );

        [DllImport("CoreDll.dll")]
        public static extern int GetSystemMemoryDivision
        (
          ref uint lpdwStorePages,
          ref uint lpdwRamPages,
          ref uint lpdwPageSize
        );

        #endregion













    }
}