gpsposition.vb

清华大学出版社出版的 移动应用开发宝典 张大威（2008）的附书源代码

Imports System.Runtime.InteropServices

Namespace Microsoft.WindowsMobile.Samples.Location

    Friend Enum FixQuality
        Unknown = 0
        Gps = 1
        DGps = 2
    End Enum

    Friend Enum FixType
        Unknown = 0
        XyD = 1
        XyzD = 2
    End Enum

    Friend Enum FixSelection
        Unknown = 0
        [Auto] = 1
        Manual = 2
    End Enum

    Public Class Satellite

        Private m_azimuth As Integer
        Private m_elevation As Integer
        Private m_id As Integer
        Private m_signalStrength As Integer

        Friend Sub New()
        End Sub

        Friend Sub New(ByVal id As Integer, ByVal elevation As Integer, ByVal azimuth As Integer, ByVal signalStrength As Integer)
            m_id = id
            m_elevation = elevation
            m_azimuth = azimuth
            m_signalStrength = signalStrength
        End Sub

        Public Property Azimuth() As Integer
            Get
                Return m_azimuth
            End Get
            Set(ByVal value As Integer)
                m_azimuth = value
            End Set
        End Property

        Public Property Elevation() As Integer
            Get
                Return m_elevation
            End Get
            Set(ByVal value As Integer)
                m_elevation = value
            End Set
        End Property

        Public Property Id() As Integer
            Get
                Return m_id
            End Get
            Set(ByVal value As Integer)
                m_id = value
            End Set
        End Property

        Public Property SignalStrength() As Integer
            Get
                Return m_signalStrength
            End Get
            Set(ByVal value As Integer)
                m_signalStrength = value
            End Set
        End Property

    End Class


    Public Class GpsPosition

        Private position As GPS_POSITION

        Friend Sub New(ByVal position As GPS_POSITION)
            Me.position = position
        End Sub

        Public Function GetSatellitesInSolution() As Satellite()
            Dim inViewSatellites As Satellite() = Me.GetSatellitesInView
            Dim list As New ArrayList
            Dim index As Integer = 0
            Do While (index < Me.position.dwSatelliteCount)
                Dim found As Satellite = Nothing
                Dim viewIndex As Integer = 0
                Do While ((viewIndex < inViewSatellites.Length) AndAlso (found Is Nothing))
                    If (Me.position.rgdwSatellitesUsedPRNs(index) = inViewSatellites(viewIndex).Id) Then
                        found = inViewSatellites(viewIndex)
                        list.Add(found)
                    End If
                    viewIndex += 1
                Loop
                index += 1
            Loop
            Return DirectCast(list.ToArray(GetType(Satellite)), Satellite())
        End Function

        Public Function GetSatellitesInView() As Satellite()
            Dim satellites As Satellite() = Nothing
            If (Me.position.dwSatellitesInView <> 0) Then
                satellites = New Satellite(Me.position.dwSatellitesInView - 1) {}
                Dim index As Integer = 0
                Do While (index < satellites.Length)
                    satellites(index) = New Satellite
                    satellites(index).Azimuth = Me.position.rgdwSatellitesInViewAzimuth(index)
                    satellites(index).Elevation = Me.position.rgdwSatellitesInViewElevation(index)
                    satellites(index).Id = Me.position.rgdwSatellitesInViewPRNs(index)
                    satellites(index).SignalStrength = Me.position.rgdwSatellitesInViewSignalToNoiseRatio(index)
                    index += 1
                Loop
            End If
            Return satellites
        End Function


        ' Properties
        Public ReadOnly Property EllipsoidAltitude() As Single
            Get
                Return Me.position.flAltitudeWRTEllipsoid
            End Get
        End Property

        Public ReadOnly Property EllipsoidAltitudeValid() As Boolean
            Get
                Return ((Me.position.dwValidFields And GPS_VALID.ALTITUDE_WRT_ELLIPSOID) <> 0)
            End Get
        End Property

        Public ReadOnly Property Heading() As Single
            Get
                Return Me.position.flHeading
            End Get
        End Property

        Public ReadOnly Property HeadingValid() As Boolean
            Get
                Return ((Me.position.dwValidFields And GPS_VALID.HEADING) <> 0)
            End Get
        End Property

        Public ReadOnly Property HorizontalDilutionOfPrecision() As Single
            Get
                Return Me.position.flHorizontalDilutionOfPrecision
            End Get
        End Property

        Public ReadOnly Property HorizontalDilutionOfPrecisionValid() As Boolean
            Get
                Return ((Me.position.dwValidFields And GPS_VALID.HORIZONTAL_DILUTION_OF_PRECISION) <> 0)
            End Get
        End Property

        Public ReadOnly Property Latitude() As Double
            Get
                Return Me.position.dblLatitude
            End Get
        End Property

        Public ReadOnly Property LatitudeInDegreesMinutesSeconds() As DegreesMinutesSeconds
            Get
                Return New DegreesMinutesSeconds(Me.position.dblLatitude)
            End Get
        End Property

        Public ReadOnly Property LatitudeValid() As Boolean
            Get
                Return ((Me.position.dwValidFields And GPS_VALID.LATITUDE) <> 0)
            End Get
        End Property

        Public ReadOnly Property Longitude() As Double
            Get
                Return Me.position.dblLongitude
            End Get
        End Property

        Public ReadOnly Property LongitudeInDegreesMinutesSeconds() As DegreesMinutesSeconds
            Get
                Return New DegreesMinutesSeconds(Me.position.dblLongitude)
            End Get
        End Property

        Public ReadOnly Property LongitudeValid() As Boolean
            Get
                Return ((Me.position.dwValidFields And GPS_VALID.LONGITUDE) <> 0)
            End Get
        End Property

        Public ReadOnly Property PositionDilutionOfPrecision() As Single
            Get
                Return Me.position.flPositionDilutionOfPrecision
            End Get
        End Property

        Public ReadOnly Property PositionDilutionOfPrecisionValid() As Boolean
            Get
                Return ((Me.position.dwValidFields And GPS_VALID.POSITION_DILUTION_OF_PRECISION) <> 0)
            End Get
        End Property

        Public ReadOnly Property SatelliteCount() As Integer
            Get
                Return Me.position.dwSatelliteCount
            End Get
        End Property

        Public ReadOnly Property SatelliteCountValid() As Boolean
            Get
                Return ((Me.position.dwValidFields And GPS_VALID.SATELLITE_COUNT) <> 0)
            End Get
        End Property

        Public ReadOnly Property SatellitesInSolutionValid() As Boolean
            Get
                Return ((Me.position.dwValidFields And GPS_VALID.SATELLITES_USED_PRNS) <> 0)
            End Get
        End Property

        Public ReadOnly Property SatellitesInViewCount() As Integer
            Get
                Return Me.position.dwSatellitesInView
            End Get
        End Property

        Public ReadOnly Property SatellitesInViewCountValid() As Boolean
            Get
                Return ((Me.position.dwValidFields And GPS_VALID.SATELLITES_IN_VIEW) <> 0)
            End Get
        End Property

        Public ReadOnly Property SatellitesInViewValid() As Boolean
            Get
                Return ((Me.position.dwValidFields And GPS_VALID.SATELLITES_IN_VIEW) <> 0)
            End Get
        End Property

        Public ReadOnly Property SeaLevelAltitude() As Single
            Get
                Return Me.position.flAltitudeWRTSeaLevel
            End Get
        End Property

        Public ReadOnly Property SeaLevelAltitudeValid() As Boolean
            Get
                Return ((Me.position.dwValidFields And GPS_VALID.ALTITUDE_WRT_SEA_LEVEL) <> 0)
            End Get
        End Property

        Public ReadOnly Property Speed() As Single
            Get
                Return Me.position.flSpeed
            End Get
        End Property

        Public ReadOnly Property SpeedValid() As Boolean
            Get
                Return ((Me.position.dwValidFields And GPS_VALID.SPEED) <> 0)
            End Get
        End Property

        Public ReadOnly Property Time() As DateTime
            Get
                Return New DateTime(Me.position.stUTCTime.year, Me.position.stUTCTime.month, Me.position.stUTCTime.day, Me.position.stUTCTime.hour, Me.position.stUTCTime.minute, Me.position.stUTCTime.second, Me.position.stUTCTime.millisecond)
            End Get
        End Property

        Public ReadOnly Property TimeValid() As Boolean
            Get
                Return ((Me.position.dwValidFields And GPS_VALID.UTC_TIME) <> 0)
            End Get
        End Property

        Public ReadOnly Property VerticalDilutionOfPrecision() As Single
            Get
                Return Me.position.flVerticalDilutionOfPrecision
            End Get
        End Property

        Public ReadOnly Property VerticalDilutionOfPrecisionValid() As Boolean
            Get
                Return ((Me.position.dwValidFields And GPS_VALID.VERTICAL_DILUTION_OF_PRECISION) <> 0)
            End Get
        End Property

    End Class

    <StructLayout(LayoutKind.Sequential)> _
    Friend Structure GPS_POSITION

        Private Const GPS_MAX_SATELLITES As Integer = 12

        Public dwVersion As Integer
        Public dwSize As Integer

        Public dwValidFields As GPS_VALID
        Public dwFlags As GPS_DATA_FLAGS

        Public stUTCTime As SYSTEMTIME

        Public dblLatitude As Double
        Public dblLongitude As Double
        Public flSpeed As Single
        Public flHeading As Single
        Public dblMagneticVariation As Double
        Public flAltitudeWRTSeaLevel As Single
        Public flAltitudeWRTEllipsoid As Single

        Public FixQuality As FixQuality
        Public FixType As FixType
        Public SelectionType As FixSelection

        Public flPositionDilutionOfPrecision As Single
        Public flHorizontalDilutionOfPrecision As Single
        Public flVerticalDilutionOfPrecision As Single

        Public dwSatelliteCount As Integer
        <MarshalAs(UnmanagedType.ByValArray, SizeConst:=12)> _
        Public rgdwSatellitesUsedPRNs As Integer()

        Public dwSatellitesInView As Integer
        <MarshalAs(UnmanagedType.ByValArray, SizeConst:=12)> _
        Public rgdwSatellitesInViewPRNs As Integer()
        <MarshalAs(UnmanagedType.ByValArray, SizeConst:=12)> _
        Public rgdwSatellitesInViewElevation As Integer()
        <MarshalAs(UnmanagedType.ByValArray, SizeConst:=12)> _
        Public rgdwSatellitesInViewAzimuth As Integer()
        <MarshalAs(UnmanagedType.ByValArray, SizeConst:=12)> _
        Public rgdwSatellitesInViewSignalToNoiseRatio As Integer()

    End Structure

    <Flags()> _
    Friend Enum GPS_VALID
        UTC_TIME = 1
        LATITUDE = 2
        LONGITUDE = 4
        SPEED = 8
        HEADING = &H10
        MAGNETIC_VARIATION = &H20
        ALTITUDE_WRT_SEA_LEVEL = &H40
        ALTITUDE_WRT_ELLIPSOID = &H80
        POSITION_DILUTION_OF_PRECISION = &H100
        HORIZONTAL_DILUTION_OF_PRECISION = &H200
        VERTICAL_DILUTION_OF_PRECISION = &H400
        SATELLITE_COUNT = &H800
        SATELLITES_USED_PRNS = &H1000
        SATELLITES_IN_VIEW = &H2000
        SATELLITES_IN_VIEW_PRNS = &H4000
        SATELLITES_IN_VIEW_ELEVATION = &H8000
        SATELLITES_IN_VIEW_AZIMUTH = &H10000
        SATELLITES_IN_VIEW_SIGNAL_TO_NOISE_RATIO = &H20000

    End Enum

    <Flags()> _
    Friend Enum GPS_DATA_FLAGS
        NONE = 0
        HARDWARE_OFF = 1
    End Enum

    <StructLayout(LayoutKind.Sequential)> _
    Friend Structure SYSTEMTIME
        Friend year As Short
        Friend month As Short
        Friend dayOfWeek As Short
        Friend day As Short
        Friend hour As Short
        Friend minute As Short
        Friend second As Short
        Friend millisecond As Short
    End Structure




End Namespace