Android的位置监听器不工作

Question

我想获得当前设备位置和开放Google Maps本：

if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) { 
     LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); 
     LocationListener locationListener = new MyLocationListener(); 
     locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 5000, 10, locationListener); 


    } else { 
     ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, MY_LOCATION_REQUEST_CODE); 
    } 




private class MyLocationListener implements LocationListener { 

    @Override 
    public void onLocationChanged(Location loc) { 

     longitude = loc.getLongitude(); 
     latitude = loc.getLatitude(); 

     Intent intent = new Intent(android.content.Intent.ACTION_VIEW, Uri.parse("http://maps.google.com/maps?saddr=" + latitude + "," + longitude + "&daddr=55.877526, 26.533898")); 
     startActivity(intent); 
    } 

    @Override 
    public void onProviderDisabled(String provider) { 
    } 

    @Override 
    public void onProviderEnabled(String provider) { 
    } 

    @Override 
    public void onStatusChanged(String provider, int status, Bundle extras) { 
    } 
} 

但这种代码是不工作：出于某些原因听众被忽略。

为什么以及如何解决它？

Answer 1

“为什么......”

因为requestLocationUpdates()是asynchorous操作和结果（位置）在onLocationChanged()回调返回。该位置不可立即使用。

“...以及如何解决它？”

移动你的谷歌地图有意向代码：

@Override 
public void onLocationChanged(Location loc) { 

    longitude = loc.getLongitude(); 
    latitude = loc.getLatitude(); 

    Intent intent = new Intent(android.content.Intent.ACTION_VIEW, Uri.parse("http://maps.google.com/maps?saddr=" + latitude + "," + longitude + "&daddr=55.877526, 26.533898")); 
    startActivity(intent); 

}