按城市或经度和纬度

Question

我使用.NET和我能够通过IP来地理定位用户的城市.NET获取时区。

有没有简单的方法通过长期得到用户的时区。和拉特。或城市名称？

我想知道Facebook是怎么做的呢？

谢谢

Answer 1

有一个Web服务，您可以使用城市或经度和纬度来获取时区：

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

Answer 2

你可以从系统时区列表并将其与城市名称：

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

这是脆弱的。

另外也有少数网络服务在那里，你可以使用，通过它长/ lat和它给你的时区，但是这意味着你是拴在第三部分Web服务。

Answer 3

我敢肯定，这个代码可以简化，但这个工作对我来说，得到时区ID和名称。

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 & "&timestamp=" & 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