无法得到gps的速度和方向信息

Question

criteria_gps = new Criteria();        
criteria_gps.setAccuracy(Criteria.ACCURACY_FINE); // 高精度       
criteria_gps.setAltitudeRequired(true);        
criteria_gps.setBearingRequired(true);        
criteria_gps.setCostAllowed(true);     
criteria_gps.setSpeedRequired(true);
criteria_gps.setPowerRequirement(Criteria.POWER_LOW); // 低功耗        
    provider_gps = locationmanager_gps.getBestProvider(criteria_gps, true); // 获取GPS信息       
locationmanager_gps.requestLocationUpdates(provider_gps, 30*1000, 100, locationlistener_gps);
getspeed()始终得到0，在真机上运行的

Answer 1

gps 这个东西真难。第三方的哪个好用呀？