Android:何时停止 gps 监听器强制关闭？

Question

当我试图停止我的 gsp 监听器时，我得到了一个强制关闭
这是代码:

mlocManager.removeUpdates(mlocListener);
mlocManager = null;  

还有这个:

LocationManager mlocManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);  
LocationListener mlocListener = new MyLocationListener();
mlocManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
(long) update, 0, mlocListener);

请帮助我，我不明白为什么它会强制关闭。

07-30 11:43:39.557: D/AndroidRuntime(1071): Shutting down VM
07-30 11:43:39.557: W/dalvikvm(1071): threadid=1: thread exiting with uncaught exception (group=0x40015560)
07-30 11:43:39.575: E/AndroidRuntime(1071): FATAL EXCEPTION: main
07-30 11:43:39.575: E/AndroidRuntime(1071): java.lang.NullPointerException
07-30 11:43:39.575: E/AndroidRuntime(1071):     at com.example.anotheractivity.Festivale$1.onClick(Festivale.java:109)
07-30 11:43:39.575: E/AndroidRuntime(1071):     at android.view.View.performClick(View.java:2485)
07-30 11:43:39.575: E/AndroidRuntime(1071):     at android.view.View$PerformClick.run(View.java:9080)
07-30 11:43:39.575: E/AndroidRuntime(1071):     at android.os.Handler.handleCallback(Handler.java:587)
07-30 11:43:39.575: E/AndroidRuntime(1071):     at android.os.Handler.dispatchMessage(Handler.java:92)
07-30 11:43:39.575: E/AndroidRuntime(1071):     at android.os.Looper.loop(Looper.java:123)
07-30 11:43:39.575: E/AndroidRuntime(1071):     at android.app.ActivityThread.main(ActivityThread.java:3683)
07-30 11:43:39.575: E/AndroidRuntime(1071):     at java.lang.reflect.Method.invokeNative(Native Method)
07-30 11:43:39.575: E/AndroidRuntime(1071):     at java.lang.reflect.Method.invoke(Method.java:507)
07-30 11:43:39.575: E/AndroidRuntime(1071):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
07-30 11:43:39.575: E/AndroidRuntime(1071):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
07-30 11:43:39.575: E/AndroidRuntime(1071):     at dalvik.system.NativeStart.main(Native Method)
07-30 11:43:41.565: I/Process(1071): Sending signal. PID: 1071 SIG: 9

Answer 1

我为此做了一项服务。使用它很容易获得经度/纬度。

1. 将此类复制/粘贴到您的项目中。

包com.sample; 导入 com.sample.globalconstant;

import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.util.Log;
import android.widget.Toast;

public class MyServiceGPS extends Service
{
    private static final String TAG = "BOOMBOOMTESTGPS";
    private LocationManager mLocationManager = null;
    private static final int LOCATION_INTERVAL = 1000;
    private static final float LOCATION_DISTANCE = 10f;

    private class LocationListener implements android.location.LocationListener{
        Location mLastLocation;
        public LocationListener(String provider)
        {
            Log.e(TAG, "LocationListener " + provider);
            mLastLocation = new Location(provider);
        }
        public void onLocationChanged(Location location)
        {
            Log.e(TAG, "onLocationChanged: " + location.getLatitude() +"....."+ location.getLongitude());
            globalconstant.lat  = location.getLatitude();
            globalconstant.lon  = location.getLongitude();
            Toast.makeText(getApplicationContext(), location.getLatitude() +"....."+ location.getLongitude(), 1000).show();
            mLastLocation.set(location);
        }
        public void onProviderDisabled(String provider)
        {
            Log.e(TAG, "onProviderDisabled: " + provider);           
        }
        public void onProviderEnabled(String provider)
        {
            Log.e(TAG, "onProviderEnabled: " + provider);
        }
        public void onStatusChanged(String provider, int status, Bundle extras)
        {
            Log.e(TAG, "onStatusChanged: " + provider);
        }
    }
    LocationListener[] mLocationListeners = new LocationListener[] {
            new LocationListener(LocationManager.GPS_PROVIDER),
            new LocationListener(LocationManager.NETWORK_PROVIDER)
    };
    @Override
    public IBinder onBind(Intent arg0)
    {
        return null;
    }
    @Override
    public int onStartCommand(Intent intent, int flags, int startId)
    {
        Log.e(TAG, "onStartCommand");
        super.onStartCommand(intent, flags, startId);      
        return START_STICKY;
    }
    @Override
    public void onCreate()
    {
        Log.e(TAG, "onCreate");
        initializeLocationManager();
        try {
            mLocationManager.requestLocationUpdates(
                    LocationManager.NETWORK_PROVIDER, LOCATION_INTERVAL, LOCATION_DISTANCE,
                    mLocationListeners[1]);

        } catch (java.lang.SecurityException ex) {
            Log.i(TAG, "fail to request location update, ignore", ex);
        } catch (IllegalArgumentException ex) {
            Log.d(TAG, "network provider does not exist, " + ex.getMessage());
        }
        try {
            mLocationManager.requestLocationUpdates(
                    LocationManager.GPS_PROVIDER, LOCATION_INTERVAL, LOCATION_DISTANCE,
                    mLocationListeners[0]);
        } catch (java.lang.SecurityException ex) {
            Log.i(TAG, "fail to request location update, ignore", ex);
        } catch (IllegalArgumentException ex) {
            Log.d(TAG, "gps provider does not exist " + ex.getMessage());
        }
    }
    @Override
    public void onDestroy()
    {
        Log.e(TAG, "onDestroy");
        super.onDestroy();
        if (mLocationManager != null) {
            for (int i = 0; i < mLocationListeners.length; i++) {
                try {
                    mLocationManager.removeUpdates(mLocationListeners[i]);
                } catch (Exception ex) {
                    Log.i(TAG, "fail to remove location listners, ignore", ex);
                }
            }
        }
    }
    private void initializeLocationManager() {
        Log.e(TAG, "initializeLocationManager");
        if (mLocationManager == null) {
            mLocationManager = (LocationManager) getApplicationContext().getSystemService(Context.LOCATION_SERVICE);
        }
    }
}

1. 在您想要开始时将此代码复制到您的 Activity 中:

   startService(new Intent(this,MyServiceGPS.class));

2. 创建一个类 globalconstant:

   公共(public)类全局常量 { 公共(public)静态双纬度，经度；

   当你想在你的项目中获取当前的经纬度时，只写这个 globalconstant.lat ,globalconstant.lon

3. 在Manifest中添加uses-permission