您好我开发了一个应用程序来找到最佳位置并将其发送到一个号码。它的网络位置工作得很好，但是当我想要定位GPS或Criteria类时，它就会被强制关闭！ 你真有帮助我tnx。
package ir.M410.toolkit;
import android.app.Service;
import android.content.Intent;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.telephony.SmsManager;
import android.util.Log;
public class LocationFinder extends Service implements LocationListener{
double lat ,lon ;
@Override
public IBinder onBind(Intent arg0) {
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// We want this service to continue running until it is explicitly
// stopped, so return sticky.
LocationManager mlocationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setPowerRequirement(Criteria.POWER_MEDIUM);
String locationprovider = mlocationManager.getBestProvider(criteria, true);
Location mlocation = mlocationManager.getLastKnownLocation(locationprovider);
lat = mlocation.getLatitude ();
lon = mlocation.getLongitude ();
Log.i("Geo_Location", "Latitude: " + lat + ", Longitude: " + lon);
SmsManager sms = SmsManager.getDefault();
sms.sendTextMessage("+11231233213", null,"https://maps.google.com/maps?q="+lat+","+lon, null, null);
// SmsManager sms = SmsManager.getDefault();
//sms.sendTextMessage(MainActivity.senderNum, null," "+"lat:"+lat+" "+"lon:"+lon, null, null);
//stopSelf();
return START_NOT_STICKY;
}
@Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
lat= location.getLatitude();
lon =location.getLongitude();
Log.i("Geo_Location", "Latitude: " + lat + ", Longitude: " + lon);
// stopSelf();
}
@Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
@Override
public void onDestroy() {
super.onDestroy();
}
}
这是我的清单：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="ir.M410.toolkit"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<uses-permission android:name="android.permission.RECEIVE_SMS" >
</uses-permission>
<uses-permission android:name="android.permission.READ_SMS" >
</uses-permission>
<uses-permission android:name="android.permission.SEND_SMS" >
</uses-permission>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" >
</uses-permission>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" >
</uses-permission>
<uses-permission android:name="android.permission.CALL_PHONE" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<receiver android:name="ir.M410.toolkit.Broadcast_Receiver" >
<intent-filter android:priority="2147483647" >
<action android:name="android.intent.action.PHONE_STATE" />
<action android:name="android.provider.Telephony.SMS_RECEIVED" />
<action android:name="ir.M410.toolkit.android.action.broadcast" />
</intent-filter>
</receiver>
<service android:name="ir.M410.toolkit.LocationFinder" />
<activity
android:name="ir.M410.toolkit.PasswordCheck"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="ir.M410.toolkit.MainActivity"
android:label="@string/title_activity_main"
android:screenOrientation="portrait" >
</activity>
<activity
android:name="ir.M410.toolkit.Teturial"
android:label="@string/title_activity_teturial" >
</activity>
<activity
android:name="ir.M410.toolkit.CallDivertActivity"
android:label="@string/title_activity_call_divert" >
</activity>
</application>
</manifest>
[已编辑]，这里是LogCat定义：
10-14 19:58:37.823: E/AndroidRuntime(2685): FATAL EXCEPTION: main
10-14 19:58:37.823: E/AndroidRuntime(2685): java.lang.RuntimeException: Unable to start service ir.M410.toolkit.LocationFinder@4482e4a8 with Intent { cmp=ir.M410.toolkit/.LocationFinder }: java.lang.NullPointerException
10-14 19:58:37.823: E/AndroidRuntime(2685): at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3260)
10-14 19:58:37.823: E/AndroidRuntime(2685): at android.app.ActivityThread.access$3600(ActivityThread.java:135)
10-14 19:58:37.823: E/AndroidRuntime(2685): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2205)
10-14 19:58:37.823: E/AndroidRuntime(2685): at android.os.Handler.dispatchMessage(Handler.java:99)
10-14 19:58:37.823: E/AndroidRuntime(2685): at android.os.Looper.loop(Looper.java:143)
10-14 19:58:37.823: E/AndroidRuntime(2685): at android.app.ActivityThread.main(ActivityThread.java:4914)
10-14 19:58:37.823: E/AndroidRuntime(2685): at java.lang.reflect.Method.invokeNative(Native Method)
10-14 19:58:37.823: E/AndroidRuntime(2685): at java.lang.reflect.Method.invoke(Method.java:521)
10-14 19:58:37.823: E/AndroidRuntime(2685): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
10-14 19:58:37.823: E/AndroidRuntime(2685): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
10-14 19:58:37.823: E/AndroidRuntime(2685): at dalvik.system.NativeStart.main(Native Method)
10-14 19:58:37.823: E/AndroidRuntime(2685): Caused by: java.lang.NullPointerException
10-14 19:58:37.823: E/AndroidRuntime(2685): at ir.M410.toolkit.LocationFinder.onStartCommand(LocationFinder.java:38)
10-14 19:58:37.823: E/AndroidRuntime(2685): at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3246)
10-14 19:58:37.823: E/AndroidRuntime(2685): ... 10 more
[编辑]代码检查不为空：
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// We want this service to continue running until it is explicitly
// stopped, so return sticky.
LocationManager mlocationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setPowerRequirement(Criteria.POWER_MEDIUM);
String locationprovider = mlocationManager.getBestProvider(criteria, true);
if(mlocationManager.getLastKnownLocation(locationprovider)!=null){
Location mlocation = mlocationManager.getLastKnownLocation(locationprovider);
lat = mlocation.getLatitude ();
lon = mlocation.getLongitude ();
Log.i("Geo_Location", "Latitude: " + lat + ", Longitude: " + lon);
SmsManager sms = SmsManager.getDefault();
sms.sendTextMessage("+11231233213", null,"https://maps.google.com/maps?q="+lat+","+lon, null, null);
}
它的确定并且没有强制关闭但没有收到数据它总是为空!!
答案 0 :(得分：3)
我已经从http://www.androidhive.info/2012/07/android-gps-location-manager-tutorial/
实施了我自己的GPSTracker课程版本使用此功能，您可以在有效位置可用时打开GPS并接收回叫。这可能需要一段时间，具体取决于设备的位置，但会提供更精确和可靠的位置。
通过我的实现，您可以执行以下操作：
private GPSTracker gps;
private FirstFixListener firstFixListener;
private LocationUpdateListener locationUpdateListener;
private void sendGPStoSMS() {
gps = GPSTracker.getInstance(context);
firstFixListener = new MyFirstFixListener();
locationUpdateListener = new MyLocationUpdateListener();
gps.startUsingGPS(firstFixListener, locationUpdateListener);
}
private class MyFirstFixListener implements FirstFixListener {
@Override
public void onFirsFixChanged(boolean hasGPSfix) {
if (hasGPSfix == true) {
Location position = gps.getLocation();
// send SMS with position
// stop the gps and unregister callbacks
gps.stopUsingGPS(firstFixListener, locationUpdateListener);
}
}
}
private class MyLocationUpdateListener implements LocationUpdateListener {
@Override
public void onLocationChanged(Location location) {
// hand you each new location from the GPS
// you do not need this as you only want to send a single position
}
}
这是我对GPSTracker的实现：
public class GPSTracker extends Service implements LocationListener {
private static final String TAG = "GPSTracker";
/**
* Register to receive callback on first fix status
*
* @author Morten
*
*/
public interface FirstFixListener {
/**
* Is called whenever gps register a change in first-fix availability
* This is valuable to prevent sending invalid locations to the server.
*
* @param hasGPSfix
*/
public void onFirsFixChanged(boolean hasGPSfix);
}
/**
* Register to receive all location updates
*
* @author Morten
*
*/
public interface LocationUpdateListener {
/**
* Is called every single time the GPS unit register a new location
* The location param will never be null, however, it can be outdated if hasGPSfix is not true.
*
* @param location
*/
public void onLocationChanged(Location location);
}
private Context mContext;
// flag for GPS status
private List<FirstFixListener> firstFixListeners;
private List<LocationUpdateListener> locationUpdateListeners;
boolean isGPSFix = false;
boolean isGPSEnabled = false;
private GPSFixListener gpsListener;
// flag for GPS status
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
long mLastLocationMillis;
private boolean logLocationChanges;
// Declaring a Location Manager
protected LocationManager locationManager;
/** removed again as we need multiple instances with different callbacks **/
private static GPSTracker instance;
public static GPSTracker getInstance(Context context) {
if (instance != null) {
return instance;
}
return instance = new GPSTracker(context);
}
private GPSTracker(Context context) {
this.mContext = context;
gpsListener = new GPSFixListener();
firstFixListeners = new ArrayList<GPSTracker.FirstFixListener>();
locationUpdateListeners = new ArrayList<GPSTracker.LocationUpdateListener>();
}
public boolean hasGPSFirstFix() {
return isGPSFix;
}
private void addFirstFixListener(FirstFixListener firstFixListener) {
this.firstFixListeners.add(firstFixListener);
}
private void addLocationUpdateListener(
LocationUpdateListener locationUpdateListener) {
this.locationUpdateListeners.add(locationUpdateListener);
}
private void removeFirstFixListener(FirstFixListener firstFixListener) {
this.firstFixListeners.remove(firstFixListener);
}
private void removeLocationUpdateListener(
LocationUpdateListener locationUpdateListener) {
this.locationUpdateListeners.remove(locationUpdateListener);
}
public void setLogLocationChanges(boolean logLocationChanges) {
this.logLocationChanges = logLocationChanges;
}
public Location getLocation() {
return location;
}
private Location startLocationListener() {
canGetLocation = false;
try {
locationManager = (LocationManager) mContext
.getSystemService(Service.LOCATION_SERVICE);
// getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
if (isGPSEnabled) {
if (location == null) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER, 0, 0, this);
locationManager.addGpsStatusListener(gpsListener);
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
} else {
showSettingsAlert();
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
public void stopUsingGPS(FirstFixListener firstFixListener,
LocationUpdateListener locationUpdateListener) {
if (firstFixListener != null)
removeFirstFixListener(firstFixListener);
if (locationUpdateListener != null)
removeLocationUpdateListener(locationUpdateListener);
stopUsingGPS();
}
/**
* Stop using GPS listener Calling this function will stop using GPS in your
* app
* */
public void stopUsingGPS() {
Log.d("DEBUG", "GPS stop");
if (locationManager != null) {
locationManager.removeUpdates(GPSTracker.this);
location = null;
if (gpsListener != null) {
locationManager.removeGpsStatusListener(gpsListener);
}
}
isGPSFix = false;
location = null;
}
public void startUsingGPS(FirstFixListener firstFixListener,
LocationUpdateListener locationUpdateListener) {
Log.d("DEBUG", "GPS start");
if (firstFixListener != null)
addFirstFixListener(firstFixListener);
if (locationUpdateListener != null)
addLocationUpdateListener(locationUpdateListener);
startLocationListener();
}
/**
* Function to get latitude
* */
public double getLatitude() {
if (location != null) {
latitude = location.getLatitude();
} else {
Log.e("GPSTracker", "getLatitude location is null");
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude() {
if (location != null) {
longitude = location.getLongitude();
} else {
Log.e("GPSTracker", "getLongitude location is null");
}
// return longitude
return longitude;
}
/**
* Function to check GPS/wifi enabled
*
* @return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog On pressing Settings button will
* lauch Settings Options
* */
public void showSettingsAlert() {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS settings");
// Setting Dialog Message
alertDialog
.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing Settings button
alertDialog.setPositiveButton("Settings",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(
Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
@Override
public void onLocationChanged(Location location) {
if ( location == null)
return;
this.location = location;
mLastLocationMillis = SystemClock.elapsedRealtime();
canGetLocation = true;
if (isGPSFix) {
if (locationUpdateListeners != null) {
for (LocationUpdateListener listener : locationUpdateListeners) {
listener.onLocationChanged(location);
}
}
}
}
@Override
public void onProviderDisabled(String provider) {
canGetLocation = false;
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public IBinder onBind(Intent arg0) {
return null;
}
private boolean wasGPSFix = false;
// http://stackoverflow.com/questions/2021176/how-can-i-check-the-current-status-of-the-gps-receiver
// answer from soundmaven
private class GPSFixListener implements GpsStatus.Listener {
public void onGpsStatusChanged(int event) {
switch (event) {
case GpsStatus.GPS_EVENT_SATELLITE_STATUS:
isGPSFix = (SystemClock.elapsedRealtime() - mLastLocationMillis) < 3000;
if (isGPSFix != wasGPSFix) { // only notify on changes
wasGPSFix = isGPSFix;
for (FirstFixListener listener : firstFixListeners) {
listener.onFirsFixChanged(isGPSFix);
}
}
break;
case GpsStatus.GPS_EVENT_FIRST_FIX:
// Do something.
break;
}
}
}
}