我有一个包含 3 个活动的应用程序，第一个是启动屏幕，第二个是主活动屏幕，第三个是 GPS 位置活动。从主活动屏幕，我调用 GPS 位置活动以通过意图检索纬度和经度。如果我像应用程序一样检查第三个活动，它工作正常。但我把它作为一个活动，我有下一个错误。
DalvikVM[localhost:8613]
Thread [<1> main] (Suspended (exception RuntimeException))
ActivityThread.performResumeActivity(IBinder, boolean) line: not available
ActivityThread.handleResumeActivity(IBinder, boolean, boolean) line: not available
ActivityThread.handleLaunchActivity(ActivityThread$ActivityClientRecord, Intent) line: not available
ActivityThread.access$600(ActivityThread, ActivityThread$ActivityClientRecord, Intent) line: not available
ActivityThread$H.handleMessage(Message) line: not available
ActivityThread$H(Handler).dispatchMessage(Message) line: not available
Looper.loop() line: not available
ActivityThread.main(String[]) line: not available
Method.invokeNative(Object, Object[], Class, Class[], Class, int, boolean) line: not available [native method]
Method.invoke(Object, Object...) line: not available
ZygoteInit$MethodAndArgsCaller.run() line: not available
ZygoteInit.main(String[]) line: not available
NativeStart.main(String[]) line: not available [native method]
Thread [<10> Binder_2] (Running)
Thread [<9> Binder_1] (Running)
Thread [<11> Binder_3] (Running)
Thread [<12> AsyncTask #1] (Running)
这是我调用第三个活动的 Asynctask 方法。
private class getLocationTask extends AsyncTask<Void, Void, Void> {
/**
* El sistema llama a este método para realizar el trabajo en un hilo
* trabajador y le entrega los parámetros dados a AsyncTask.execute()
*/
protected Void doInBackground(Void... params) {
// In the method that is called when click on "update". Go to the 2
// activity
Intent intent = new Intent(getBaseContext(),
getLocationActivity.class);
startActivityForResult(intent, 0); // 0 is a detectable code
return null;
}
@Override
protected void onPostExecute(Void result) {
}
}
我做错了什么？
获取位置代码
package victor.martin.noow;
import android.annotation.SuppressLint;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.provider.Settings;
import android.support.v4.app.DialogFragment;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import java.io.IOException;
import java.util.List;
import java.util.Locale;
public class getLocationActivity extends FragmentActivity {
private TextView mLatLng;
private TextView mAddress;
private Button mFineProviderButton;
private Button mBothProviderButton;
private LocationManager mLocationManager;
private Handler mHandler;
private boolean mGeocoderAvailable;
private boolean mUseFine;
private boolean mUseBoth;
private double latitude, longitude;
private String street;
// Keys for maintaining UI states after rotation.
private static final String KEY_FINE = "use_fine";
private static final String KEY_BOTH = "use_both";
// UI handler codes.
private static final int UPDATE_ADDRESS = 1;
private static final int UPDATE_LATLNG = 2;
private static final int TEN_SECONDS = 10000;
private static final int TEN_METERS = 10;
private static final int TWO_MINUTES = 1000 * 60 * 2;
/**
* This sample demonstrates how to incorporate location based services in
* your app and process location updates. The app also shows how to convert
* lat/long coordinates to human-readable addresses.
*/
@SuppressLint("NewApi")
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.location_layout);
// Restore apps state (if exists) after rotation.
if (savedInstanceState != null) {
mUseFine = savedInstanceState.getBoolean(KEY_FINE);
mUseBoth = savedInstanceState.getBoolean(KEY_BOTH);
} else {
mUseFine = false;
mUseBoth = false;
}
mLatLng = (TextView) findViewById(R.id.latlng);
mAddress = (TextView) findViewById(R.id.address);
// Receive location updates from the fine location provider (gps) only.
//mFineProviderButton = (Button) findViewById(R.id.provider_fine);
// Receive location updates from both the fine (gps) and coarse
// (network) location
// providers.
//mBothProviderButton = (Button) findViewById(R.id.provider_both);
// The isPresent() helper method is only available on Gingerbread or
// above.
mGeocoderAvailable = Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD
&& Geocoder.isPresent();
// Handler for updating text fields on the UI like the lat/long and
// address.
mHandler = new Handler() {
public void handleMessage(Message msg) {
switch (msg.what) {
case UPDATE_ADDRESS:
//mAddress.setText((String) msg.obj);
break;
case UPDATE_LATLNG:
//mLatLng.setText((String) msg.obj);
break;
}
}
};
// Get a reference to the LocationManager object.
mLocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
}
// Restores UI states after rotation.
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putBoolean(KEY_FINE, mUseFine);
outState.putBoolean(KEY_BOTH, mUseBoth);
}
@Override
protected void onResume() {
super.onResume();
setup();
}
@Override
protected void onStart() {
super.onStart();
// Check if the GPS setting is currently enabled on the device.
// This verification should be done during onStart() because the system
// calls this method
// when the user returns to the activity, which ensures the desired
// location provider is
// enabled each time the activity resumes from the stopped state.
LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
final boolean gpsEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
if (!gpsEnabled) {
// Build an alert dialog here that requests that the user enable
// the location services, then when the user clicks the "OK" button,
// call enableLocationSettings()
new EnableGpsDialogFragment().show(getSupportFragmentManager(),
"enableGpsDialog");
}
}
// Method to launch Settings
private void enableLocationSettings() {
Intent settingsIntent = new Intent(
Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(settingsIntent);
}
// Stop receiving location updates whenever the Activity becomes invisible.
@Override
protected void onStop() {
super.onStop();
mLocationManager.removeUpdates(listener);
}
// Set up fine and/or coarse location providers depending on whether the
// fine provider or
// both providers button is pressed.
private void setup() {
Location gpsLocation = null;
Location networkLocation = null;
mLocationManager.removeUpdates(listener);
mLatLng.setText(R.string.unknown);
mAddress.setText(R.string.unknown);
// Get fine location updates only.
if (mUseFine) {
//mFineProviderButton.setBackgroundResource(R.drawable.button_active);
//mBothProviderButton.setBackgroundResource(R.drawable.button_inactive);
// Request updates from just the fine (gps) provider.
gpsLocation = requestUpdatesFromProvider(
LocationManager.GPS_PROVIDER, R.string.not_support_gps);
// Update the UI immediately if a location is obtained.
if (gpsLocation != null)
updateUILocation(gpsLocation);
} else if (mUseBoth) {
// Get coarse and fine location updates.
//mFineProviderButton.setBackgroundResource(R.drawable.button_inactive);
//mBothProviderButton.setBackgroundResource(R.drawable.button_active);
// Request updates from both fine (gps) and coarse (network)
// providers.
gpsLocation = requestUpdatesFromProvider(
LocationManager.GPS_PROVIDER, R.string.not_support_gps);
networkLocation = requestUpdatesFromProvider(
LocationManager.NETWORK_PROVIDER,
R.string.not_support_network);
// If both providers return last known locations, compare the two
// and use the better
// one to update the UI. If only one provider returns a location,
// use it.
if (gpsLocation != null && networkLocation != null) {
updateUILocation(getBetterLocation(gpsLocation, networkLocation));
} else if (gpsLocation != null) {
updateUILocation(gpsLocation);
} else if (networkLocation != null) {
updateUILocation(networkLocation);
}
}
}
/**
* Method to register location updates with a desired location provider. If
* the requested provider is not available on the device, the app displays a
* Toast with a message referenced by a resource id.
*
* @param provider
* Name of the requested provider.
* @param errorResId
* Resource id for the string message to be displayed if the
* provider does not exist on the device.
* @return A previously returned {@link android.location.Location} from the
* requested provider, if exists.
*/
private Location requestUpdatesFromProvider(final String provider,
final int errorResId) {
Location location = null;
if (mLocationManager.isProviderEnabled(provider)) {
mLocationManager.requestLocationUpdates(provider, TEN_SECONDS,
TEN_METERS, listener);
location = mLocationManager.getLastKnownLocation(provider);
} else {
Toast.makeText(this, errorResId, Toast.LENGTH_LONG).show();
}
return location;
}
// Callback method for the "fine provider" button.
public void useFineProvider(View v) {
mUseFine = true;
mUseBoth = false;
setup();
}
// Callback method for the "both providers" button.
public void useCoarseFineProviders(View v) {
mUseFine = false;
mUseBoth = true;
setup();
}
private void doReverseGeocoding(Location location) {
// Since the geocoding API is synchronous and may take a while. You
// don't want to lock
// up the UI thread. Invoking reverse geocoding in an AsyncTask.
(new ReverseGeocodingTask(this)).execute(new Location[] { location });
}
private void updateUILocation(Location location) {
// We're sending the update to a handler which then updates the UI with
// the new
// location.
Message.obtain(mHandler, UPDATE_LATLNG,
location.getLatitude() + ", " + location.getLongitude())
.sendToTarget();
// Bypass reverse-geocoding only if the Geocoder service is available on
// the device.
if (mGeocoderAvailable)
doReverseGeocoding(location);
}
private final LocationListener listener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
// A new location update is received. Do something useful with it.
// Update the UI with
// the location update.
updateUILocation(location);
}
@Override
public void onProviderDisabled(String provider) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
};
/**
* Determines whether one Location reading is better than the current
* Location fix. Code taken from
* http://developer.android.com/guide/topics/location
* /obtaining-user-location.html
*
* @param newLocation
* The new Location that you want to evaluate
* @param currentBestLocation
* The current Location fix, to which you want to compare the new
* one
* @return The better Location object based on recency and accuracy.
*/
protected Location getBetterLocation(Location newLocation,
Location currentBestLocation) {
if (currentBestLocation == null) {
// A new location is always better than no location
return newLocation;
}
// Check whether the new location fix is newer or older
long timeDelta = newLocation.getTime() - currentBestLocation.getTime();
boolean isSignificantlyNewer = timeDelta > TWO_MINUTES;
boolean isSignificantlyOlder = timeDelta < -TWO_MINUTES;
boolean isNewer = timeDelta > 0;
// If it's been more than two minutes since the current location, use
// the new location
// because the user has likely moved.
if (isSignificantlyNewer) {
return newLocation;
// If the new location is more than two minutes older, it must be
// worse
} else if (isSignificantlyOlder) {
return currentBestLocation;
}
// Check whether the new location fix is more or less accurate
int accuracyDelta = (int) (newLocation.getAccuracy() - currentBestLocation
.getAccuracy());
boolean isLessAccurate = accuracyDelta > 0;
boolean isMoreAccurate = accuracyDelta < 0;
boolean isSignificantlyLessAccurate = accuracyDelta > 200;
// Check if the old and new location are from the same provider
boolean isFromSameProvider = isSameProvider(newLocation.getProvider(),
currentBestLocation.getProvider());
// Determine location quality using a combination of timeliness and
// accuracy
if (isMoreAccurate) {
return newLocation;
} else if (isNewer && !isLessAccurate) {
return newLocation;
} else if (isNewer && !isSignificantlyLessAccurate
&& isFromSameProvider) {
return newLocation;
}
return currentBestLocation;
}
/** Checks whether two providers are the same */
private boolean isSameProvider(String provider1, String provider2) {
if (provider1 == null) {
return provider2 == null;
}
return provider1.equals(provider2);
}
// AsyncTask encapsulating the reverse-geocoding API. Since the geocoder API
// is blocked,
// we do not want to invoke it from the UI thread.
private class ReverseGeocodingTask extends AsyncTask<Location, Void, Void> {
Context mContext;
public ReverseGeocodingTask(Context context) {
super();
mContext = context;
}
@Override
protected Void doInBackground(Location... params) {
Geocoder geocoder = new Geocoder(mContext, Locale.getDefault());
Location loc = params[0];
List<Address> addresses = null;
try {
mUseFine = false;
mUseBoth = true;
setup();
addresses = geocoder.getFromLocation(loc.getLatitude(),
loc.getLongitude(), 1);
latitude = loc.getLatitude();
longitude = loc.getLongitude();
Log.i("GETLOC-INFO", ">>>>" + latitude + " / " + longitude);
} catch (IOException e) {
e.printStackTrace();
// Update address field with the exception.
Message.obtain(mHandler, UPDATE_ADDRESS, e.toString())
.sendToTarget();
}
if (addresses != null && addresses.size() > 0) {
Address address = addresses.get(0);
// Format the first line of address (if available), city, and
// country name.
String addressText = String.format(
"%s, %s, %s",
address.getMaxAddressLineIndex() > 0 ? address
.getAddressLine(0) : "", address.getLocality(),
address.getCountryName());
street = addressText;
// Update address field on UI.
Message.obtain(mHandler, UPDATE_ADDRESS, addressText)
.sendToTarget();
}
if (latitude != 0.0) { // We got data
// Send the data to the Main Activity
Intent data = new Intent();
data.putExtra("latitude", latitude);
data.putExtra("longitude", longitude);
data.putExtra("street", street);
setResult(RESULT_OK, data);
}
return null;
}
}
/**
* Dialog to prompt users to enable GPS on the device.
*/
@SuppressLint("ValidFragment")
private class EnableGpsDialogFragment extends DialogFragment {
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
return new AlertDialog.Builder(getActivity())
.setTitle(R.string.enable_gps)
.setMessage(R.string.enable_gps_dialog)
.setPositiveButton(R.string.enable_gps,
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
enableLocationSettings();
}
}).create();
}
}
}
我从 Android 开发人员指南 -> LocationAware 示例中获取代码。它有 2 个按钮来调用 2 种不同的方法来获取位置。我更改了一些代码以使其在活动开始时开始获取位置。