.NET 按城市或经纬度获取时区

Question

我正在使用 .NET，并且能够通过 IP 对用户城市进行地理定位。

有没有简单的方法可以长时间获取用户时区。和纬度。或城市名称？

我想知道 Facebook 是如何做到的？

谢谢

Answer 1

您可以使用一个网络服务来按城市或经度和纬度获取时区：

http:// /www.earthtools.org/webservices.htm#timezone

Answer 2

您可以从系统获取时区列表并将其与城市名称进行比较：

http://msdn.microsoft.com/en-us/library/bb397781.aspx

这是脆弱的。

或者，您可以使用一些网络服务，传递长/纬度，它会为您提供时区，但这意味着您受到第三方网络服务的束缚。

Answer 3

我确信这段代码可以简化，但这对我获取时区 ID 和名称很有用。

Private Sub checkTZ()
    Dim wc As WebClient = New WebClient()
    Dim str As String = Nothing
    Dim latPattern As String = "\bLatitude.*\<{1}"
    Dim latRegSearch As Regex = New Regex(latPattern)
    Dim lat As String = Nothing
    Dim lonPattern As String = "\bLongitude.*\<{1}"
    Dim lonRegSearch As Regex = New Regex(lonPattern)
    Dim lon As String = Nothing

    Try
        str = wc.DownloadString("http://www.ipinfodb.com/my_ip_location.php")
        lat = latRegSearch.Match(str).Value
        lon = lonRegSearch.Match(str).Value
    Catch ex As Exception
        str = "Not Found"
    End Try

    Dim pattern As String = "\<|\s|\:|\bLatitude|\bLongitude"
    Dim rgx As New Regex(pattern)
    lat = rgx.Replace(lat, "")
    lon = rgx.Replace(lon, "")

    Dim firefoxEpochDate As Date = "1/1/1970"
    Dim s_CurrentGoogleAPI As Long = DateDiff(DateInterval.Second, firefoxEpochDate, DateTime.UtcNow)
    Dim xmldoc As XmlDocument = New XmlDocument()
    Dim results2 As String = wc.DownloadString("https://maps.googleapis.com/maps/api/timezone/xml?location=" & lat & "," & lon & "×tamp=" & s_CurrentGoogleAPI)
    xmldoc.LoadXml(results2)
    Dim tz_offset_hours As Double = (Convert.ToDouble(xmldoc.DocumentElement.Item("raw_offset").InnerText) + Convert.ToDouble(xmldoc.DocumentElement.Item("dst_offset").InnerText)) / 3600
End Sub