Delphi获取Android下GPS的NMEA 0183数据

下面的程序，可以实现Android下获取GNSS的NMEA0183数据：

unit utAndroidNmea;

interface

uses Androidapi.JNIBridge, Androidapi.JNI.App, Androidapi.NativeActivity, Androidapi.JNI.JavaTypes, Androidapi.JNI.Location;

type

  TonNmeaReceived=procedure(timestamp: Int64; nmea: String) of Object;

  TJGpsStatus_NmeaListener = class(TJavaGenericImport<JGpsStatus_NmeaListenerClass, JGpsStatus_NmeaListener>) end;

  TNmeaProvider=class(TJavaLocal,JGpsStatus_NmeaListenerClass, JGpsStatus_NmeaListener)

  protected

    FLocationManager:JLocationManager;

    FOnNmeaReceived:TonNmeaReceived;

  public

    procedure onNmeaReceived(timestamp: Int64; nmea: JString); cdecl;

  public

    constructor Create;

    destructor Destroy;override;

    function Run:Boolean;

    property OnNmeaLineReceived:TOnNmeaReceived read FOnNmeaReceived write FOnNmeaReceived;

  end;

implementation

uses Androidapi.Helpers, Androidapi.JNI.GraphicsContentViewText,  FMX.Helpers.Android,

FMX.Platform.Android, System.SysUtils, System.Android.Sensors;

{ TNmea }

constructor TNmeaProvider.Create;

begin

  inherited Create;

end;

destructor TNmeaProvider.Destroy;

begin

  if Assigned(FLocationManager) then FLocationManager.removeNmeaListener(Self );

  inherited;

end;

procedure TNmeaProvider.onNmeaReceived(timestamp: Int64; nmea: JString); cdecl;

begin

  if Assigned(FOnNmeaReceived) then FOnNmeaReceived(timestamp, JStringToString(nmea));

end;

function TNmeaProvider.Run:Boolean;

begin

  CallInUiThread(procedure

  var

    LocationService: JObject;

  begin

    LocationService := SharedActivityContext.getSystemService(TJContext.JavaClass.LOCATION_SERVICE);

    FLocationManager := TJLocationManager.Wrap((LocationService as ILocalObject).GetObjectID);

    FLocationManager.addNmeaListener(Self);

  end);

end;

end.

用法：

在Form中添加一个TLocationSensor, 设置Active:=True;

然后定义OnNmeaReceive方法：

procedure TForm1.OnNmeaReceived(timestamp: int64; nmeasentence: String);

begin

  FStream.Write(PChar(nmeasentence)^, Length(nmeasentence)*sizeof(Char));

end;