android - 如何检查 GPS 是否已连接以及位置是否已更新

Question

GPS 需要连接到 GPS 卫星才能实时跟踪位置。问题是有时它可能会失去连接，如果我调用

    locationManager.getLastKnownLocation(provider);

我得到可能与实际位置不同的最后已知位置。如何在调用/使用 getLastKnownLocation 之前检查 GPS 是否已连接以及位置是否已更新？

Answer 1

实现GpsStatus.Listener Activity 或 Service 上的接口(interface):

public class LocationActivity extends Activity implements GpsStatus.Listener
{

   private LocationManager locationManager;

   @Override
   public void onCreate(Bundle savdedInstanceState)
       ....
       ....
       locationManager = (LocationManager)getSystemService(LOCATION_SERVICE);
       locationManager.addGpsStatusListener(this);
   }

   @Override
   public void onGpsStatusChanged(int event) 
   {

      switch (event) 
      {
        case GpsStatus.GPS_EVENT_SATELLITE_STATUS:
        break;
        case GpsStatus.GPS_EVENT_FIRST_FIX:  
        /* This is when GPS is activated; add code here for how you want the application to react. */                        
        break;
        case GpsStatus.GPS_EVENT_STARTED:
        break;
        case GpsStatus.GPS_EVENT_STOPPED:
        break;
      }
   }
}