在 WM 平台上开发 GPS 导航系统

核心提示：101 End Class102方向和速度提醒GPS设备分析您的位置，随着时间的推移来计算速度和影响，在 WM 平台上开发 GPS 导航系统(9)，在本文开头$ GPRMC语句也包括这些数据，速度在每个节点都是始终要记录的，全球定位系统的力量再一次证明了一行代码，表单1-5的数字，轴承以“方位”来记录，从0 °到360

101 End Class

102

方向和速度提醒

GPS设备分析您的位置，随着时间的推移来计算速度和影响。在本文开头$ GPRMC语句也包括这些数据。速度在每个节点都是始终要记录的，轴承以“方位”来记录，从0 °到360 °顺时针其中0 °表示北， 90 °表示东等。因此在地平线上测量。要应用数学公式转换成英里每小时。全球定位系统的力量再一次证明了一行代码。表单1-5的数字，显示汽车是否超过时速限制。

代码片段：

1 '*******************************************************

2

3 '** Listing 1-5. Extracting speed and bearing

4

5 '*******************************************************

6

7 Public Class NmeaInterpreter

8 ' Raised when the current location has changed

9 Public Event PositionReceived(ByVal latitude As String, _

10 ByVal longitude As String)

11 Public Event DateTimeChanged(ByVal dateTime As DateTime)

12 Public Event BearingReceived(ByVal bearing As Double)

13 Public Event SpeedReceived(ByVal speed As Double)

14 Public Event SpeedLimitReached()

15 ' Processes information from the GPS receiver

16 Public Function Parse(ByVal sentence As String) As Boolean

17 ' Discard the sentence if its checksum does not match our calculated

18 ' checksum

19 If Not IsValid(sentence) Then Return False

20 ' Look at the first word to decide where to go next

21 Select Case GetWords(sentence)(0)

22 Case "$GPRMC" ' A "Recommended Minimum" sentence was found!

23 Return ParseGPRMC(sentence)

24 Case Else

25 ' Indicate that the sentence was not recognized

26 Return False

27 End Select

28 End Function

29 ' Divides a sentence into individual words

30 Public Function GetWords(ByVal sentence As String) As String()

31 Return sentence.Split(","c)