I am trying to get a redirect from Google Maps using a project that is currently only at .Net Framework 4.0.
Take Microsoft's mailing address as an example:
1 Microsoft Way, Redmond, WA
Format a string that replaces Spaces , Commas , with Plus + signs:
https://www.google.com/maps?daddr=1+microsoft+way+redmond+wa
By the time Google finishes processing the page, the final URL has the Latitude and Longitude:
I need the Latitude and Longitude from this URL.
I found this article already on SO:
Get a collection of redirected URLs from HttpWebResponse
Using the solution there, I created this very similar looking method:
private String latitude, longitude;
private void GetLatLongFromAddress(String p_street_name, String p_city, String p_state, String p_postal_code)
{
var street_name = String.Format("{0}", p_street_name.Replace(' ', '+')).Trim();
var city = String.Format("{0}", p_city).Trim();
var state = String.Format("{0}", p_state).Trim();
var postal_code = String.Format("{0}", p_postal_code).Trim();
var mapUrl = String.Format("http://maps.google.com/?daddr={0}+{1}+{2}+{3}",
street_name, city, state, postal_code);
var location = String.Copy(mapUrl);
while (!String.IsNullOrEmpty(location))
{
var req1 = (HttpWebRequest)HttpWebRequest.Create(location);
req1.AllowAutoRedirect = false;
// give page time to redirect?
// System.Threading.Thread.Sleep(5000);
using (var resp = (HttpWebResponse)req1.GetResponse())
{
location = resp.GetResponseHeader("Location");
if (!String.IsNullOrEmpty(location))
{
var postalIndex = location.IndexOf(postal_code);
var slashAtIndex = location.IndexOf("/@") + 1;
if ((postalIndex < slashAtIndex) && (slashAtIndex < location.Length))
{
var split = location.Substring(slashAtIndex).Split(',');
latitude = split[0];
longitude = split[1];
}
}
}
}
}
You can see where I format the original URL with this line:
var mapUrl = String.Format("http://maps.google.com/?daddr={0}+{1}+{2}+{3}",
street_name, city, state, postal_code);
The problem is with this line:
location = resp.GetResponseHeader("Location");
Every time I get the response, the returned location value is the same as the mapUrl value that I started with because Google does not redirect it immediately.
I tried adding a Sleep(5000) call, but that did not change anything.
How would I go about getting the final redirect?
