sdk/samples/all in on code/Visual Studio 2010/VBAzureBingMaps/DAL/Travel.vb

   1 '***************************** Module Header ******************************\
   2 '* Module Name: Travel.vb
   3 '* Project:             AzureBingMaps
   4 '* Copyright (c) Microsoft Corporation.
   5 '*
   6 '* Partial class for the Travel EF entity.
   7 '*
   8 '* This source is subject to the Microsoft Public License.
   9 '* See http://www.microsoft.com/opensource/licenses.mspx#Ms-PL.
  10 '* All other rights reserved.
  11 '*
  12 '* THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,
  13 '* EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
  14 '* WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
  15 '\**************************************************************************
  16
  17
  18 Imports System.Data.Objects.DataClasses
  19 Imports System.Data.Services
  20 Imports System.Data.Services.Common
  21 Imports System.IO
  22 Imports Microsoft.SqlServer.Types
  23
  24 ''' <summary>
  25 ''' The partial class for the Travel EF entity.
  26 ''' Both PartitionKey and RowKey are part of data service key.
  27 ''' Properties such as EntityState and EntityKey should not be passed to the client.
  28 ''' The binary representation GeoLocation does not need to be passed to the client as well.
  29 ''' </summary>
  30 <DataServiceKey(New String() {"PartitionKey", "RowKey"})> _
  31 <IgnoreProperties(New String() {"EntityState", "EntityKey", "GeoLocation"})> _
  32 Partial Public Class Travel
  33     Inherits EntityObject
  34     Private _geoLocationText As String
  35
  36     ''' <summary>
  37     ''' The text representation of the geo location, which is more user friendly.
  38     ''' When Latitude and Longitude are modified, GeoLocationText will be modified as well.
  39     ''' Client may upload an entity with Latitude/Longitude, but without GeoLocationText, so its value could be null.
  40     ''' To avoid unintentionally setting GeoLocaionText to null, let's check the value in setter.
  41     ''' </summary>
  42     Public Property GeoLocationText() As String
  43         Get
  44             Return Me._geoLocationText
  45         End Get
  46         Set(ByVal value As String)
  47             If Not String.IsNullOrEmpty(value) Then
  48                 Me._geoLocationText = value
  49             End If
  50         End Set
  51     End Property
  52
  53     ' When either latitude or longitude changes, GeoLocationText must be changed as well.
  54     ' The binary GeoLocation does not need to be changed, as it is only known by the database.
  55     Private _latitude As Double
  56     Public Property Latitude() As Double
  57         Get
  58             Return Me._latitude
  59         End Get
  60         Set(ByVal value As Double)
  61             Me._latitude = value
  62             Me.GeoLocationText = Me.LatLongToWKT(Me.Latitude, Me.Longitude)
  63         End Set
  64     End Property
  65
  66     Private _longitude As Double
  67     Public Property Longitude() As Double
  68         Get
  69             Return Me._longitude
  70         End Get
  71         Set(ByVal value As Double)
  72             Me._longitude = value
  73             Me.GeoLocationText = Me.LatLongToWKT(Me.Latitude, Me.Longitude)
  74         End Set
  75     End Property
  76
  77     ''' <summary>
  78     ''' Convert latitude and longitude to WKT.
  79     ''' </summary>
  80     Private Function LatLongToWKT(ByVal latitude As Double, ByVal longitude As Double) As String
  81         Dim sqlGeography__1 As SqlGeography = SqlGeography.Point(latitude, longitude, 4326)
  82         Return sqlGeography__1.ToString()
  83     End Function
  84
  85     ''' <summary>
  86     ''' GeoLocationText, Latitude, Longitude do not correspond to any column in the database.
  87     ''' Geolocation (binary) corresponds to the GeoLocation column in the TravelView.
  88     ''' If the binary GeoLocation changes, those values should be modified as well.
  89     ''' This could happen when querying the entity.
  90     ''' </summary>
  91     Private Sub OnGeoLocationChanging(ByVal value As Global.System.Byte())
  92         If value IsNot Nothing Then
  93             Using ms As New MemoryStream(value)
  94                 Using reader As New BinaryReader(ms)
  95                     Dim sqlGeography As New SqlGeography()
  96                     sqlGeography.Read(reader)
  97                     Me.GeoLocationText = New String(sqlGeography.STAsText().Value)
  98                     Me.Latitude = sqlGeography.Lat.Value
  99                     Me.Longitude = sqlGeography.[Long].Value
 100                 End Using
 101             End Using
 102         End If
 103     End Sub
 104 End Class