Question

我有一个问题。当我测试这个。我要求showCurrentLocation函数它总是返回null。当我发送位置后，它在模拟器中工作。但是我需要这个才能在手机上工作，而且你不能像在de DDNS窗口那样发送这个位置。

这是我的代码

public class LbsGeocodingActivity extends Activity {

private static final long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES = 1; // in Meters
private static final long MINIMUM_TIME_BETWEEN_UPDATES = 1; // in Milliseconds

protected LocationManager locationManager;

protected Button retrieveLocationButton;
protected Button stopLocationButton;


@Override
public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    retrieveLocationButton = (Button) findViewById(R.id.retrieve_location_button);
    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

    locationManager.requestLocationUpdates(
            LocationManager.GPS_PROVIDER, 
            MINIMUM_TIME_BETWEEN_UPDATES, 
            MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
            new MyLocationListener()
    );

    retrieveLocationButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            showCurrentLocation();
        }
    });  
    /*stopLocationButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            //locationManager.removeUpdates(MyLocationListener)  ;          
        }
    }); */ 

}    

public String getMyPhoneNumber(){
    TelephonyManager mTelephonyMgr;
    mTelephonyMgr = (TelephonyManager)
    getSystemService(Context.TELEPHONY_SERVICE); 
    return mTelephonyMgr.getLine1Number();
}

protected void showCurrentLocation() {

    Criteria crit = new Criteria();
    crit.setAccuracy(Criteria.ACCURACY_FINE);
    String provider = locationManager.getBestProvider(crit, true);
    Location loc = locationManager.getLastKnownLocation(provider);


    if (loc != null) {
        String longi = "" + loc.getLongitude();
        String lat = "" + loc.getLatitude();
        String num = getMyPhoneNumber();
        String message = String.format(
                "Current Location \n  Longitude: %1$s \n Latitude: %2$s \n %3$s ",
                longi,
                lat,
                num         );
        Toast.makeText(LbsGeocodingActivity.this, message,
                Toast.LENGTH_LONG).show();
    }
    if (loc == null)Toast.makeText(LbsGeocodingActivity.this, "Null ",
            Toast.LENGTH_LONG).show();
}   

private class MyLocationListener implements LocationListener {



    public void onLocationChanged(Location loc) {
        String longi = "" + loc.getLongitude();
        String lat = "" + loc.getLatitude();
        String num = getMyPhoneNumber();
        String message = String.format(
                "New Location \n Longitude: %1$s \n Latitude: %2$s \n %3$s ",
                longi,
                lat,
                num                 );
        Toast.makeText(LbsGeocodingActivity.this, message, Toast.LENGTH_LONG).show();
    }

    public void onStatusChanged(String s, int i, Bundle b) {
        Toast.makeText(LbsGeocodingActivity.this, "Provider status changed",
                Toast.LENGTH_LONG).show();
    }

    public void onProviderDisabled(String s) {
        Toast.makeText(LbsGeocodingActivity.this,
                "Provider disabled by the user. GPS turned off",
                Toast.LENGTH_LONG).show();
    }

    public void onProviderEnabled(String s) {
        Toast.makeText(LbsGeocodingActivity.this,
                "Provider enabled by the user. GPS turned on",
                Toast.LENGTH_LONG).show();
    }

}

}

我的权限是：FINE_LOCATION COURSE_LOCATION。

我真的只是希望它跟踪用户的位置，即使在背景上也是如此..

Answer 1

您也可以将模拟位置发送到您的Android设备上 Android mock location on device?

然后，除了我有这个问题，它似乎也许从来没有在您的设备上的位置尝试打开谷歌地图，并确保你找到位置，然后再试一次。此外，我怀疑第一次使用您无法访问最后知道位置的应用程序，因为您从未使用它，因此您首先需要找到位置，下次启动应用程序时它将起作用。如果您想快速定位，请尝试通过wifi或手机信号塔找到位置

并确保设置权限！

Answer 2

您是否检查过手机中的GPS已打开，打开GPS后需要一段时间才能获得位置更新。

Locationmanager getLastKnownLocation始终为null

2 个答案: