我的Android应用程序有问题。我需要一个应用程序，它将获得后台GPS位置，同时打开另一个application.application在后台运行，但我想在后台获得GPS位置。
创建开始和停止按钮以获取正常工作的gps位置但是当点击主页按钮时gps停止以获取位置
这是我的代码..
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_gps);
/* get TextView to display the GPS data */
txtLat = (TextView) findViewById(R.id.textview1);
/* the location manager is the most vital part it allows access
* to location and GPS status services */
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER ,10000,10, this);
// locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 10 * 1000L, 0, this);
btnShow = (Button) findViewById(R.id.btnstart);
btnStop = (Button) findViewById(R.id.btnstop);
btnShow.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
Toast.makeText(getBaseContext(), "Trip Start.", Toast.LENGTH_SHORT).show();
txtLat.setVisibility(View.VISIBLE);
onResume();
btnShow.setEnabled(false);
btnStop.setEnabled(true);
}
});
Button btnstop = (Button) findViewById(R.id.btnstop);
btnstop.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
onPause();
Toast.makeText(getBaseContext(), "Trip Ended.", Toast.LENGTH_SHORT).show();
btnShow.setEnabled(true);
btnStop.setEnabled(false);
}
});
}
public void onLocationChanged(Location location) {
if (location == null) {
Toast.makeText(getApplicationContext(),"Searching for your location.", Toast.LENGTH_SHORT).show();
locationManager.requestLocationUpdates(provider, 10000, 10,locationListener);
onLocationChanged(location);
}
else
{
double cell_lat=location.getLatitude();
double cell_long=location.getLongitude();
double altitude=location.getAltitude();
double accuracy=location.getAccuracy();
String status="true";
sb = new StringBuilder(512);
noOfFixes++;
/* display some of the data in the TextView */
sb.append("Tracking: ");
sb.append(noOfFixes);
sb.append('\n');
sb.append('\n');
sb.append("Londitude: ");
sb.append(location.getLongitude());
sb.append('\n');
sb.append("Latitude: ");
sb.append(location.getLatitude());
sb.append('\n');
sb.append("Altitiude: ");
sb.append(location.getAltitude());
sb.append('\n');
sb.append("Accuracy: ");
sb.append(location.getAccuracy());
sb.append("ft");
sb.append('\n');
txtLat.setText(sb.toString());
}
public void onProviderDisabled(String provider) {
/* this is called if/when the GPS is disabled in settings */
Log.v(tag, "Disabled");
/* bring up the GPS settings */
Intent intent = new Intent(
android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(intent);
}
public void onProviderEnabled(String provider) {
Log.v(tag, "Enabled");
Toast.makeText(this, "GPS Enabled", Toast.LENGTH_SHORT).show();
}
public void onStatusChanged(String provider, int status, Bundle extras) {
/* This is called when the GPS status alters */
switch (status) {
case LocationProvider.OUT_OF_SERVICE:
Log.v(tag, "Status Changed: Out of Service");
Toast`enter code here`.makeText(this, "Status Changed: Out of Service",
Toast.LENGTH_SHORT).show();
break;
case LocationProvider.TEMPORARILY_UNAVAILABLE:
Log.v(tag, "Status Changed: Temporarily Unavailable");
Toast.makeText(this, "Status Changed: Temporarily Unavailable",
Toast.LENGTH_SHORT).show();
break;
case LocationProvider.AVAILABLE:
Log.v(tag, "Status Changed: Available");
Toast.makeText(this, "Status Changed: Available",
Toast.LENGTH_SHORT).show();
break;
}
}
@Override
protected void onResume() {
/*
* onResume is is always called after onStart, even if the app hasn't been
* paused
*
* add location listener and request updates every 1000ms or 10m
*/
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 10f, this);
super.onResume();
}
@Override
protected void onPause() {
/* GPS, as it turns out, consumes battery like crazy */
locationManager.removeUp`enter code here`dates(this);
super.onPause();
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if ((keyCode == KeyEvent.KEYCODE_HOME)) {
System.out.println("KEYCODE_HOME");
Toast.makeText(getBaseContext(), "Home Button.", Toast.LENGTH_SHORT).show();
this.moveTaskToBack(true);
//showDialog("'HOME'");
return true;
}
if ((keyCode == KeyEvent.KEYCODE_BACK)) {
System.out.println("KEYCODE_BACK");
finish();
showDialog("'BACK'");
return true;
}
if ((keyCode == KeyEvent.KEYCODE_MENU)) {
System.out.println("KEYCODE_MENU");
//showDialog("'MENU'");
return true;
}
return false;
}
void showDialog(String the_key){
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage("You have pressed the " + the_key + " button. Would you like to exit the app?")
.setCancelable(true)
.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
finish();
}
})
.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
AlertDialog alert = builder.create();
alert.setTitle("GPS.");
alert.show();
}
答案 0 :(得分：1)
我发现这个代码在某个地方它对LINK有用，我根据我的要求修改了代码，试一试。
它从后台服务保存数据库中的数据，您只需要从活动启动服务，注意：只有当第一个位置的距离超过给定的最小距离时，它才会保存在数据库中。
public class BackgroundLocationService extends Service implements
GooglePlayServicesClient.ConnectionCallbacks,
GooglePlayServicesClient.OnConnectionFailedListener, LocationListener {
private static final String TAG = "BackgroundLocationService";
IBinder mBinder = new LocalBinder();
private LocationClient mLocationClient;
private LocationRequest mLocationRequest;
// Flag that indicates if a request is underway.
private boolean mInProgress;
private Boolean servicesAvailable = false;
private double previousLatitude = 0;
private double previousLongitude = 0;
private SharedPreferences stopLocatinServicePreferance;
private float[] distance;
// public static boolean isStopSelf = false;
public class LocalBinder extends Binder {
public BackgroundLocationService getServerInstance() {
return BackgroundLocationService.this;
}
}
@Override
public void onCreate() {
super.onCreate();
mInProgress = false;
// Create the LocationRequest object
mLocationRequest = LocationRequest.create();
// Use high accuracy
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
// Set the update interval to 5 seconds
mLocationRequest.setInterval(Constants.UPDATE_INTERVAL);
// Set the fastest update interval to 1 second
mLocationRequest.setFastestInterval(Constants.FASTEST_INTERVAL);
servicesAvailable = servicesConnected();
/*
* Create a new location client, using the enclosing class to handle
* callbacks.
*/
mLocationClient = new LocationClient(this, this, this);
}
private boolean servicesConnected() {
// Check that Google Play services is available
int resultCode = GooglePlayServicesUtil
.isGooglePlayServicesAvailable(this);
// If Google Play services is available
if (ConnectionResult.SUCCESS == resultCode) {
return true;
} else {
return false;
}
}
public int onStartCommand(Intent intent, int flags, int startId) {
super.onStartCommand(intent, flags, startId);
if (!servicesAvailable || mLocationClient.isConnected() || mInProgress)
return START_STICKY;
setUpLocationClientIfNeeded();
if (!mLocationClient.isConnected() || !mLocationClient.isConnecting()
&& !mInProgress) {
appendLog(DateFormat.getDateTimeInstance().format(new Date())
+ ": Started", Constants.LOG_FILE);
mInProgress = true;
mLocationClient.connect();
}
return START_STICKY;
}
/*
* Create a new location client, using the enclosing class to handle
* callbacks.
*/
private void setUpLocationClientIfNeeded() {
if (mLocationClient == null)
mLocationClient = new LocationClient(this, this, this);
}
// Define the callback method that receives location updates
@Override
public void onLocationChanged(Location location) {
// Report to the UI that the location was updated
String msg = Double.toString(location.getLatitude()) + ","
+ Double.toString(location.getLongitude());
Log.d("debug", msg);
SimpleDateFormat s = new SimpleDateFormat("ddMMyyyyhhmmss");
String timeStamp = s.format(new Date());
System.out.println("TimeStamp ddMMyyyyhhmmss =" + timeStamp);
if (isDistanceAccountable(location.getLatitude(),
location.getLongitude(), previousLatitude, previousLongitude)) {
DatabaseHelper dbm = DatabaseHelper
.getInstance(getApplicationContext());
ContentValues cv = new ContentValues();
cv.put(DatabaseHelper.KEY_LATLONG, location.getLatitude() + "@"
+ location.getLongitude());
cv.put(DatabaseHelper.KEY_TIMESTAMP, timeStamp);
cv.put(DatabaseHelper.KEY_STATUS, "0");
cv.put(DatabaseHelper.KEY_USER_ID, "");
dbm.insert(DatabaseHelper.TABLE_TRACKINFO_TABLE, cv);
// }
// Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();
appendLog(msg, Constants.LOCATION_FILE);
}
previousLatitude = location.getLatitude();
previousLongitude = location.getLongitude();
stopLocatinServicePreferance = getSharedPreferences("SERVICE_PREF", 0);
boolean check = stopLocatinServicePreferance.getBoolean("isStop", true);
Log.e(TAG, "isStop?" + check);
if (check) {
Log.e(TAG, "is self stoping ");
if (mLocationClient != null) {
mLocationClient.removeLocationUpdates(this);
// Destroy the current location client
mLocationClient = null;
}
this.stopSelf();
}
}
/**
* Returns true if distance is grater than MINIMUM_DISTANCE_ACCOUNTABLE
* NOTE: returns true if there is no previousLatitude,previousLongitude, it
* means this is first time it needs to save the data
*
* @param currentLatitude
* @param currentLongitude
* @param previousLatitude
* @param previousLongitude
* @return
*/
private boolean isDistanceAccountable(double currentLatitude,
double currentLongitude, double previousLatitude,
double previousLongitude) {
distance = new float[1];
if (previousLatitude > 0 && previousLongitude > 0) {
Location.distanceBetween(currentLatitude, currentLongitude,
previousLatitude, previousLongitude, distance);
Log.v(TAG + " > isDistanceAccountable()", "previousLatitude = "
+ previousLatitude + "previousLongitude = "
+ previousLongitude + " currentLatitude = "
+ currentLatitude + " , currentLongitude = "
+ currentLongitude);
} else {
Log.v(TAG + " > isDistanceAccountable()", "previousLatitude = "
+ previousLatitude + "previousLongitude = "
+ previousLongitude);
return true;
}
if (distance[0] > Constants.MINIMUM_DISTANCE_ACCOUNTABLE) {
Log.v(TAG + " > isDistanceAccountable()", "Distance = "
+ distance[0] + "return true");
return true;
} else {
Log.v(TAG + " > isDistanceAccountable()", "Distance = "
+ distance[0] + "return false");
return false;
}
}
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}
public String getTime() {
SimpleDateFormat mDateFormat = new SimpleDateFormat(
"yyyy-MM-dd HH:mm:ss");
return mDateFormat.format(new Date());
}
public void appendLog(String text, String filename) {
File logFile = new File(filename);
if (!logFile.exists()) {
try {
logFile.createNewFile();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
try {
// BufferedWriter for performance, true to set append to file flag
BufferedWriter buf = new BufferedWriter(new FileWriter(logFile,
true));
buf.append(text);
buf.newLine();
buf.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
@Override
public void onDestroy() {
try {
// Turn off the request flag
mInProgress = false;
if (servicesAvailable && mLocationClient != null) {
mLocationClient.removeLocationUpdates(this);
// Destroy the current location client
mLocationClient = null;
}
appendLog(DateFormat.getDateTimeInstance().format(new Date())
+ ": Stopped", Constants.LOG_FILE);
} catch (Exception e) {
Log.e(TAG + " > onDestroy()", e.toString());
}
super.onDestroy();
}
/*
* Called by Location Services when the request to connect the client
* finishes successfully. At this point, you can request the current
* location or start periodic updates
*/
@Override
public void onConnected(Bundle bundle) {
// Request location updates using static settings
mLocationClient.requestLocationUpdates(mLocationRequest, this);
appendLog(DateFormat.getDateTimeInstance().format(new Date())
+ ": Connected", Constants.LOG_FILE);
}
/*
* Called by Location Services if the connection to the location client
* drops because of an error.
*/
@Override
public void onDisconnected() {
// Turn off the request flag
mInProgress = false;
// Destroy the current location client
mLocationClient = null;
appendLog(DateFormat.getDateTimeInstance().format(new Date())
+ ": Disconnected", Constants.LOG_FILE);
}
/*
* Called by Location Services if the attempt to Location Services fails.
*/
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
mInProgress = false;
/*
* Google Play services can resolve some errors it detects. If the error
* has a resolution, try sending an Intent to start a Google Play
* services activity that can resolve error.
*/
if (connectionResult.hasResolution()) {
// If no resolution is available, display an error dialog
} else {
}
}
}
这是支持班。
public final class Constants {
// Milliseconds per second
private static final int MILLISECONDS_PER_SECOND = 100;
// Update frequency in seconds
private static final int UPDATE_INTERVAL_IN_SECONDS = 10;
// Update frequency in milliseconds
public static final long UPDATE_INTERVAL = MILLISECONDS_PER_SECOND
* UPDATE_INTERVAL_IN_SECONDS;
// The fastest update frequency, in seconds
private static final int FASTEST_INTERVAL_IN_SECONDS = 10;
// A fast frequency ceiling in milliseconds
public static final long FASTEST_INTERVAL = MILLISECONDS_PER_SECOND
* FASTEST_INTERVAL_IN_SECONDS;
// Stores the lat / long pairs in a text file
public static final String LOCATION_FILE = "sdcard/location.txt";
// Stores the connect / disconnect data in a text file
public static final String LOG_FILE = "sdcard/log.txt";
// Minimum accountable distance in meters
public static final float MINIMUM_DISTANCE_ACCOUNTABLE = 50;
/**
* Suppress default constructor for noninstantiability
*/
private Constants() {
throw new AssertionError();
}
}