我的应用程序需要定期进行位置修复,即使手机没有唤醒也要这样做。
为此,我使用了Commonsware慷慨提供的IntentService模式。
https://github.com/commonsguy/cwac-wakeful
为了获得位置修复,我依赖于一位名叫Fedor的成员提供的以下代码。
What is the simplest and most robust way to get the user's current location on Android?。我稍微修改了它,以返回null而不是获取最后已知的位置。
它们两个在单独使用时都非常好用:我可以从Fedor的类中获取Activity中的位置修复,并且我可以使用Commonsware类执行一些基本操作(例如记录某些内容)。
问题出现在当我尝试从Commonsware的WakefulIntentService子类获取位置修复时。LocationListeners无法对locationUpdates做出反应,我收到这些警告(我还不理解线程、处理程序等细节...)。有人能帮我理解问题是什么吗?谢谢,祝大家新年快乐 :)
这是我的WakefulIntentService子类:
它们两个在单独使用时都非常好用:我可以从Fedor的类中获取Activity中的位置修复,并且我可以使用Commonsware类执行一些基本操作(例如记录某些内容)。
问题出现在当我尝试从Commonsware的WakefulIntentService子类获取位置修复时。LocationListeners无法对locationUpdates做出反应,我收到这些警告(我还不理解线程、处理程序等细节...)。有人能帮我理解问题是什么吗?谢谢,祝大家新年快乐 :)
12-31 14:09:33.664: W/MessageQueue(3264): Handler (android.location.LocationManager$ListenerTransport$1) {41403330} sending message to a Handler on a dead thread
12-31 14:09:33.664: W/MessageQueue(3264): java.lang.RuntimeException: Handler (android.location.LocationManager$ListenerTransport$1) {41403330} sending message to a Handler on a dead thread
12-31 14:09:33.664: W/MessageQueue(3264): at android.os.MessageQueue.enqueueMessage(MessageQueue.java:196)
12-31 14:09:33.664: W/MessageQueue(3264): at android.os.Handler.sendMessageAtTime(Handler.java:473)
12-31 14:09:33.664: W/MessageQueue(3264): at android.os.Handler.sendMessageDelayed(Handler.java:446)
12-31 14:09:33.664: W/MessageQueue(3264): at android.os.Handler.sendMessage(Handler.java:383)
12-31 14:09:33.664: W/MessageQueue(3264): at android.location.LocationManager$ListenerTransport.onLocationChanged(LocationManager.java:193)
12-31 14:09:33.664: W/MessageQueue(3264): at android.location.ILocationListener$Stub.onTransact(ILocationListener.java:58)
12-31 14:09:33.664: W/MessageQueue(3264): at android.os.Binder.execTransact(Binder.java:338)
12-31 14:09:33.664: W/MessageQueue(3264): at dalvik.system.NativeStart.run(Native Method)
这是我的WakefulIntentService子类:
public class AppService extends WakefulIntentService {
public static final String TAG = "AppService";
public AppService() {
super("AppService");
}
public LocationResult locationResult = new LocationResult() {
@Override
public void gotLocation(final Location location) {
if (location == null)
Log.d(TAG, "location could not be retrieved");
else
sendMessage(location);
}
};
@Override
protected void doWakefulWork(Intent intent) {
PhoneLocation myLocation;
myLocation = new PhoneLocation();
myLocation.getLocation(getApplicationContext(), locationResult);
}
这里是Fedor类的一个副本(稍作修改:不需要GPS或最后已知位置)
public class PhoneLocation {
public static String TAG = "MyLocation";
Timer timer1;
LocationManager lm;
LocationResult locationResult;
boolean gps_enabled=false;
boolean network_enabled=false;
public boolean getLocation(Context context, LocationResult result)
{
//I use LocationResult callback class to pass location value from MyLocation to user code.
locationResult=result;
if(lm==null) lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
//exceptions will be thrown if provider is not permitted.
try{gps_enabled=lm.isProviderEnabled(LocationManager.GPS_PROVIDER);}catch(Exception ex){}
try{network_enabled=lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);}catch(Exception ex){}
//don't start listeners if no provider is enabled
if(!gps_enabled && !network_enabled)
return false;
if(network_enabled) lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListenerNetwork);
timer1=new Timer();
timer1.schedule(new ReturnNullLocation(), 20000);
return true;
}
LocationListener locationListenerNetwork = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(location);
lm.removeUpdates(this);
}
public void onProviderDisabled(String provider) {}
public void onProviderEnabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
class ReturnNullLocation extends TimerTask {
@Override
public void run() {
lm.removeUpdates(locationListenerNetwork);
locationResult.gotLocation(null);
}
}
public static abstract class LocationResult{
public abstract void gotLocation(Location location);
}
}
Intent
上提供LocationPoller.EXTRA_PROVIDER
额外信息,指示要使用哪个位置提供程序。如果您对此组件有其他问题,请使用“提问”按钮,而不是在此处发布评论。 - CommonsWare