CNClrLib.Device Namespace

The CNClrLib.Device namespace allows application developers to easily access the computer's location by using a single API. Location information may come from multiple providers, such as GPS, Wi-Fi triangulation, and cell phone tower triangulation. The CNClrLib.Device interfaces provide a single API to encapsulate the multiple location providers on a computer and support seamless prioritization and transitioning between them. As a result, application developers who use this API do not need to tailor applications to specific hardware configurations. These interfaces are defined as classes and interfaces in C# System.Device.Location Namespace.

Examples

The following example shows how to handle StatusChanged events and print out the current GeoPositionStatus.

Delphi

program DeviceLocationExample;

{$APPTYPE CONSOLE}
{$R *.res}

uses
  SysUtils,
  CNClrLib.EnumArrays,
  CNClrLib.EnumTypes,
  CNClrLib.Device,
  CNClrLib.Host,
  CNClrLib.Host.Helper,
  CNClrLib.Host.Utils,
  CNClrLib.Core;

var
  Console: _Console;

  // Event Handler in C# looks like this:
  // static void DoStatusChanged(object sender, GeoPositionStatusChangedEventArgs e)
  procedure DoStatusChanged(ASender: _ClrObject; AEventArgs: _ClrEventArgs); stdcall;
  var
    e: _GeoPositionStatusChangedEventArgs;
    ageoPositionStatus: TGeoPositionStatus;
  begin
    //Convert EventArgs value to GeoPositionStatusChangedEventArgs
    e := CoGeoPositionStatusChangedEventArgs.Wrap(AEventArgs.EventArgs);

    //Convert the status as TOleEnum to a delphi readable enumration type defined in CNClrLib.EnumTypes
    ageoPositionStatus := TGeoPositionStatus(OleEnumToOrd(GeoPositionStatusValues, e.Status));
    case ageoPositionStatus of
      gpsInitializing: Console.WriteLine_14('Working on location fix');
      gpsReady:        Console.WriteLine_14('Have location');
      gpsNoData:       Console.WriteLine_14('No data');
      gpsDisabled:     Console.WriteLine_14('Disabled');
    end;
  end;

  procedure ShowStatusUpdates;
  var
    watcher: _GeoCoordinateWatcher;
    eventHandler: TClrEventHandler;
  begin
    watcher := CoGeoCoordinateWatcher.CreateInstance;
    watcher.Start;

    eventHandler := DoStatusChanged;
    watcher.Add_StatusChanged(TClrIntPtrHelper.Zero, TClrConvert.ToManagedPointer(@eventHandler));

    Console.WriteLine_14('Enter any key to quit.');
    Console.ReadLine;
  end;

begin
  try
    Console := CoConsole.CreateInstance;
    ShowStatusUpdates;
  except
    on E: Exception do
    begin
      Console.WriteLine_14(E.message);
    end;
  end;
end.

ExamplesThe following example shows how to resolve a CivicAddress from a GeoCoordinate location synchronously.

Delphi

program ResolveAddressSync;

{$APPTYPE CONSOLE}
{$R *.res}

uses
  SysUtils,
  CNClrLib.EnumTypes,
  CNClrLib.Device,
  CNClrLib.Core;

var
  Console: _Console;

  procedure ResolveAddressSync;
  var
    watcher: _GeoCoordinateWatcher;
    resolver: _CivicAddressResolver;
    location: _GeoCoordinate;
    timespan: _TimeSpanHelper;
    address: _CivicAddress;
  begin
    watcher := CoGeoCoordinateWatcher.CreateInstance(gpaHigh);
    watcher.MovementThreshold := 1.0; // set to one meter

    timespan := CoTimeSpanHelper.CreateInstance;
    watcher.TryStart(false, timespan.FromMilliseconds(1000));

    resolver := CoCivicAddressResolver.CreateInstance;
    location := CoGeoCoordinate.Wrap(watcher.Position.Location);

    if location.IsUnknown = False then
    begin
       address := resolver.ResolveAddress(location);
      if not address.IsUnknown then
      begin
        Console.WriteLine_17('Country: {0}, Zip: {1}',
                address.CountryRegion,
                address.PostalCode);
      end
    end
    else
    begin
      Console.WriteLine_14('Address unknown.');
    end;
  end;

begin
  try
    Console := CoConsole.CreateInstance;
    ResolveAddressSync;
  except
    on E: Exception do
    begin
      Console.WriteLine_14(E.message);
    end;
  end;
end.

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