请告诉我如何解决。
class t1 implements Runnable {
private Thread t;
private Context mContext;
public void run() { GPSTracker gps = gps = new GPSTracker(mContext);}
public void start ()
{ t = new Thread (); t.start ();
}
}
public class GPSTracker extends Service implements LocationListener {
private final Context mContext;
boolean isGPSEnabled = false;
boolean isNetworkEnabled = false;
boolean canGetLocation = false;
Location location;
double latitude;
double longitude;
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10;
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1;
protected LocationManager locationManager;
public GPSTracker(Context context) {
this.mContext = context;
getLocation();
}
public Location getLocation() {
try {
// my code is not passing into the below line showing given error
locationManager = (LocationManager) mContext.getSystemService(LOCATION_SERVICE);
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
} else {
this.canGetLocation = true;
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
if (isGPSEnabled) {
if (location == null) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS Enabled", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
} catch (Exception e) {
}
return location;
}
public void stopUsingGPS(){
if(locationManager != null){
locationManager.removeUpdates(GPSTracker.this);
}
}
public double getLatitude(){
if(location != null){
System.out.println("S66");
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
public double getLongitude(){
if(location != null){
System.out.println("S67");
longitude = location.getLongitude();
}
return longitude;
}
public boolean canGetLocation() {
return this.canGetLocation;
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onProviderDisabled(String provider) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public IBinder onBind(Intent arg0) {
return null;
}
}
当我运行此代码时出现此错误：
03-06 03:22:20.017: E/AndroidRuntime(908): FATAL EXCEPTION: main
03-06 03:22:20.017: E/AndroidRuntime(908): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.g1/com.example.g1.MainActivity}: java.lang.IllegalStateException: System services not available to Activities before onCreate()
03-06 03:22:20.017: E/AndroidRuntime(908): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
03-06 03:22:20.017: E/AndroidRuntime(908): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
03-06 03:22:20.017: E/AndroidRuntime(908): at android.app.ActivityThread.access$600(ActivityThread.java:141)
03-06 03:22:20.017: E/AndroidRuntime(908): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
03-06 03:22:20.017: E/AndroidRuntime(908): at android.os.Handler.dispatchMessage(Handler.java:99)
03-06 03:22:20.017: E/AndroidRuntime(908): at android.os.Looper.loop(Looper.java:137)
03-06 03:22:20.017: E/AndroidRuntime(908): at android.app.ActivityThread.main(ActivityThread.java:5041)
03-06 03:22:20.017: E/AndroidRuntime(908): at java.lang.reflect.Method.invokeNative(Native Method)
03-06 03:22:20.017: E/AndroidRuntime(908): at java.lang.reflect.Method.invoke(Method.java:511)
03-06 03:22:20.017: E/AndroidRuntime(908): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
03-06 03:22:20.017: E/AndroidRuntime(908): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
03-06 03:22:20.017: E/AndroidRuntime(908): at dalvik.system.NativeStart.main(Native Method)
03-06 03:22:20.017: E/AndroidRuntime(908): Caused by: java.lang.IllegalStateException: System services not available to Activities before onCreate()
03-06 03:22:20.017: E/AndroidRuntime(908): at android.app.Activity.getSystemService(Activity.java:4463)
03-06 03:22:20.017: E/AndroidRuntime(908): at com.example.g1.GPSTracker.<init>(GPSTracker.java:46)
03-06 03:22:20.017: E/AndroidRuntime(908): at com.example.g1.t1.run(t1.java:23)
03-06 03:22:20.017: E/AndroidRuntime(908): at com.example.g1.MainActivity.onCreate(MainActivity.java:17)
03-06 03:22:20.017: E/AndroidRuntime(908): at android.app.Activity.performCreate(Activity.java:5104)
03-06 03:22:20.017: E/AndroidRuntime(908): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
03-06 03:22:20.017: E/AndroidRuntime(908): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
03-06 03:22:20.017: E/AndroidRuntime(908): ... 11 more