GeoCoordinate.IsUnknown Property   
Definition
Important
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Gets a value that indicates whether the GeoCoordinate does not contain latitude or longitude data.
public:
 property bool IsUnknown { bool get(); };public bool IsUnknown { get; }member this.IsUnknown : boolPublic ReadOnly Property IsUnknown As BooleanProperty Value
true if the GeoCoordinate does not contain latitude or longitude data; otherwise, false.
Examples
The following code example verifies whether the GeoCoordinate that corresponds to a location is Unknown before printing out its latitude and longitude.
using System;
using System.Device.Location;
namespace GetLocationPropertyHandleUnknown
{
    class Program
    {
        static void Main(string[] args)
        {
            GetLocationPropertyHandleUnknown();
        }
        static void GetLocationPropertyHandleUnknown()
        {
            GeoCoordinateWatcher watcher = new GeoCoordinateWatcher();
            watcher.TryStart(false, TimeSpan.FromMilliseconds(1000));
            if (!watcher.Position.Location.IsUnknown)
            {
                GeoCoordinate coord = watcher.Position.Location;
                Console.WriteLine("Lat: {0}, Long: {1}",
                    coord.Latitude,
                    coord.Longitude);
            }
            else
            {
                Console.WriteLine("Unknown");
            }
        }
    }
}
Imports System.Device.Location
Module GetLocationProperty
    Public Sub GetLocationPropertyHandleUnknown()
        Dim watcher As New System.Device.Location.GeoCoordinateWatcher()
        watcher.TryStart(False, TimeSpan.FromMilliseconds(1000))
        If watcher.Position.Location.IsUnknown <> True Then
            Dim coord As GeoCoordinate = watcher.Position.Location
            Console.WriteLine("Lat: {0}, Long: {1}", coord.Latitude, coord.Longitude)
        Else
            Console.WriteLine("Unknown latitude and longitude.")
        End If
    End Sub
    Public Sub Main()
        GetLocationPropertyHandleUnknown()
        Console.ReadLine()
    End Sub
End Module
Remarks
A GeoCoordinate that does not contain latitude or longitude data is equal to Unknown.