delphi xe6 调用java GPS的方法

如果用xe6自带的LocationSensor控件，默认优先使用网络位置，网络位置定位精度不准确，不能满足高精度定位的要求。但xe6自带的LocationSensor控件不能指定网络定位优先还是GPS定位优先，如果调用java API是可以指定优先使用GPS定位，以下代码经实测证实是可以直接指定GPS定位的。

 

uses Androidapi.JNI.Location, Androidapi.JNIBridge, Androidapi.JNI.JavaTypes, 

  Androidapi.JNI.Os,FMX.Helpers.Android,Androidapi.JNI.GraphicsContentViewText;

 

type

  TLocationListener = class;

  TForm1 = class(TForm)

 

  . . . . . .

 

  private

    { Private declarations }

    FLocationManager : JLocationManager;

    locationListener : TLocationListener;

  public

    destructor Destroy; override;

    { Public declarations }

    procedure onLocationChanged(location: JLocation);

  end;

  //Sensore GPS

  TLocationListener = class(TJavaLocal, JLocationListener)

  private

    [weak]

    FParent : TForm1;

  public

    constructor Create(AParent : TForm1);

    procedure onLocationChanged(location: JLocation); cdecl;

    procedure onProviderDisabled(provider: JString); cdecl;

    procedure onProviderEnabled(provider: JString); cdecl;

    procedure onStatusChanged(provider: JString; status: Integer; extras: JBundle); cdecl;

  end;

 

. . . . .

 

constructor TLocationListener.Create(AParent: TForm1);

begin

  inherited Create;

  FParent := AParent;

end;

 

procedure TLocationListener.onLocationChanged(location: JLocation);

begin

  FParent.onLocationChanged(location);

end;

 

procedure TLocationListener.onProviderDisabled(provider: JString);

begin

end;

 

procedure TLocationListener.onProviderEnabled(provider: JString);

begin

end;

 

procedure TLocationListener.onStatusChanged(provider: JString; status: Integer; extras: JBundle);

begin

end;

 

destructor TForm1.Destroy;

begin

  if Assigned(locationListener) then

    FLocationManager.removeUpdates(locationListener);

  inherited;

end;

 

procedure TForm1.onLocationChanged(location: JLocation);//位置发生变化时，显示经、纬度

begin

  if Assigned(location) then

  begin

     //variabili da recuperare dal sensore

     Label4.Text := location.getLatitude.ToString;

     Label5.Text := location.getLongitude.ToString;

     Label6.Text := location.getAltitude.ToString;

     Label8.Text := location.getSpeed.ToString;

     Label10.Text := location.getTime.ToString;

  end;

end;

 

procedure TForm1.FormCreate(Sender: TObject);

var LocationManagerService: JObject;

    location : JLocation;

begin 

  if not Assigned(FLocationManager) then

  begin

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

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

    if not Assigned(locationListener) then locationListener := TLocationListener.Create(self);

    FLocationManager.requestLocationUpdates(TJLocationManager.JavaClass.GPS_PROVIDER, 1000, 0, locationListener, TJLooper.JavaClass.getMainLooper);

      // 监听状态
      // 绑定监听，有4个参数
      // 参数1，设备：有GPS_PROVIDER和NETWORK_PROVIDER两种
      // 参数2，位置信息更新周期，单位毫秒
      // 参数3，位置变化最小距离：当位置距离变化超过此值时，将更新位置信息
      // 参数4，监听
      // 备注：参数2和3，如果参数3不为0，则以参数3为准；参数3为0，则通过时间来定时更新；两者为0，则随时刷新
      // 1秒更新一次，或最小位移变化超过1米更新一次；
      // 注意：此处更新准确度非常低，推荐在service里面启动一个Thread，在run中sleep(10000);然后执行handler.sendMessage(),更新位置

  end;

 FLocationManager.isProviderEnabled(TJLocationManager.JavaClass.GPS_PROVIDER);

  FLocationManager.isProviderEnabled(TJLocationManager.JavaClass.NETWORK_PROVIDER);

  onLocationChanged(location);

end