Get Latitude and Longitude from Address using nominatim openstreetmap API in ASP.Net

Hi ahmadsubuhanl,

I have created the sample using the following documentation.

https://nominatim.org/release-docs/develop/api/Search/#examples

HTML

<asp:TextBox ID="txtLocation" runat="server"></asp:TextBox>
<asp:Button ID="btnFind" runat="server" Text="Find Location" OnClick="OnSubmit" />
<hr />
Latitude:
<asp:Label ID="lblLatitude" runat="server"></asp:Label><br />
Longitude:
<asp:Label ID="lblLongitude" runat="server"></asp:Label>

Namespaces

C#

using System.Net;
using System.Web;
using Newtonsoft.Json;

VB.Net

Imports System.Net
Imports System.Web
Imports Newtonsoft.Json

Code

C#

protected void OnSubmit(object sender, EventArgs e)
{
    string url = string.Format("https://nominatim.openstreetmap.org/search?q={0}&format=json&addressdetails=1&limit=1", HttpUtility.UrlEncode(txtLocation.Text));
    ServicePointManager.Expect100Continue = true;
    ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072;
    WebClient webClient = new WebClient();
    webClient.Headers.Add(HttpRequestHeader.UserAgent, "/");
    string json = webClient.DownloadString(url);
    List<Place> places = JsonConvert.DeserializeObject<List<Place>>(json);
    lblLatitude.Text = places[0].lat;
    lblLongitude.Text = places[0].lon;
}

public class Address
{
    public string historic { get; set; }
    public string house_number { get; set; }
    public string road { get; set; }
    public string neighbourhood { get; set; }
    public string suburb { get; set; }
    public string borough { get; set; }
    public string city { get; set; }
    [JsonProperty("ISO3166-2-lvl4")]
    public string ISO31662lvl4 { get; set; }
    public string postcode { get; set; }
    public string country { get; set; }
    public string country_code { get; set; }
}

public class Place
{
    public int place_id { get; set; }
    public string licence { get; set; }
    public string osm_type { get; set; }
    public int osm_id { get; set; }
    public string lat { get; set; }
    public string lon { get; set; }
    public string @class { get; set; }
    public string type { get; set; }
    public int place_rank { get; set; }
    public double importance { get; set; }
    public string addresstype { get; set; }
    public string name { get; set; }
    public string display_name { get; set; }
    public Address address { get; set; }
    public List<string> boundingbox { get; set; }
    public string svg { get; set; }
}

VB.Net

Protected Sub OnSubmit(sender As Object, e As EventArgs)
    Dim url As String = String.Format("https://nominatim.openstreetmap.org/search?q={0}&format=json&addressdetails=1&limit=1", HttpUtility.UrlEncode(txtLocation.Text))
    ServicePointManager.Expect100Continue = True
    ServicePointManager.SecurityProtocol = CType(3072, SecurityProtocolType)
    Dim webClient As WebClient = New WebClient()
    webClient.Headers.Add(HttpRequestHeader.UserAgent, "/")
    Dim json As String = webClient.DownloadString(url)
    Dim places As List(Of Place) = JsonConvert.DeserializeObject(Of List(Of Place))(json)
    lblLatitude.Text = places(0).lat
    lblLongitude.Text = places(0).lon
End Sub

Public Class Address
    Public Property historic As String
    Public Property house_number As String
    Public Property road As String
    Public Property neighbourhood As String
    Public Property suburb As String
    Public Property borough As String
    Public Property city As String
    <JsonProperty("ISO3166-2-lvl4")>
    Public Property ISO31662lvl4 As String
    Public Property postcode As String
    Public Property country As String
    Public Property country_code As String
End Class

Public Class Place
    Public Property place_id As Integer
    Public Property licence As String
    Public Property osm_type As String
    Public Property osm_id As Integer
    Public Property lat As String
    Public Property lon As String
    Public Property [class] As String
    Public Property type As String
    Public Property place_rank As Integer
    Public Property importance As Double
    Public Property addresstype As String
    Public Property name As String
    Public Property display_name As String
    Public Property address As Address
    Public Property boundingbox As List(Of String)
    Public Property svg As String
End Class

Screenshot