您好我正在尝试制作gps检测应用。 它工作正常。但是在几个时间间隔之后没有任何事情发生或 ANR 错误即将来临。 如果我增加 LocationRequest.setInterval 值（比如 1分），那么这个问题就解决了，但由于这个原因，我无法准确地绘制折线作为获取距离两个位置的增加请帮助我。
public class MainActivity extends AppCompatActivity implements GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener, LocationListener {
private Button btnShowLocation;
private String TAG = "app";
private GoogleMap mGoogleMap;
private String mLastUpdateTime;
private TextView tvText;
private Marker mapMarker;
private List<Location> loc = new ArrayList<>();
float distance, changeDistance;
private Location mCurrentLocation;
private List<Marker> marker;
double latitude;
double longitude;
private static final long INTERVAL = 3000; //3 sec
private static final long FASTEST_INTERVAL = 2500;
private GoogleApiClient mGoogleApiClient;
private LocationRequest mLocationRequest;
protected void createLocationRequest() {
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(INTERVAL);
mLocationRequest.setSmallestDisplacement(5);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
mLocationRequest.setFastestInterval(FASTEST_INTERVAL);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnShowLocation = (Button) findViewById(R.id.textview1);
marker = new ArrayList<>();
try {
initilizeMap();
} catch (Exception e) {
e.printStackTrace();
}
tvText = (TextView) findViewById(R.id.text1);
if (!isGooglePlayServicesAvailable()) {
finish();
}
createLocationRequest();
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addApi(LocationServices.API)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.build();
updateUI();
}
private void initilizeMap() {
mGoogleMap = ((MapFragment) getFragmentManager().findFragmentById(
R.id.map)).getMap();
// mGoogleMap.clear();
mGoogleMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
addMarker(mGoogleMap.getMyLocation());
if (mGoogleMap == null) {
Toast.makeText(getApplicationContext(),
"Sorry! unable to create maps", Toast.LENGTH_SHORT)
.show();
}
}
private void addMarker(Location loc) {
MarkerOptions options = new MarkerOptions();
options.icon(BitmapDescriptorFactory.defaultMarker());
LatLng currentLatLng = new LatLng(loc.getLatitude(), loc.getLongitude());
options.position(currentLatLng);
mapMarker = mGoogleMap.addMarker(options);
mapMarker.setDraggable(true);
mapMarker.showInfoWindow();
marker.add(mapMarker);
Log.d("size marker", marker.size() + " ");
long atTime = mCurrentLocation.getTime();
mLastUpdateTime = DateFormat.getTimeInstance().format(new Date(atTime));
mapMarker.setTitle(mLastUpdateTime + " distance " + distance + "m");
mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(currentLatLng,
15));
}
@Override
public void onStart() {
super.onStart();
Log.d(TAG, "onStart fired ");
mGoogleApiClient.connect();
}
@Override
public void onStop() {
super.onStop();
Log.d(TAG, "onStop fired ");
mGoogleApiClient.disconnect();
Log.d(TAG, "isConnected : " + mGoogleApiClient.isConnected());
}
private boolean isGooglePlayServicesAvailable() {
int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
if (ConnectionResult.SUCCESS == status) {
return true;
} else {
GooglePlayServicesUtil.getErrorDialog(status, this, 0).show();
return false;
}
}
@Override
public void onConnected(Bundle bundle) {
Log.d(TAG, "onConnected - isConnected: " + mGoogleApiClient.isConnected());
startLocationUpdates();
}
protected void startLocationUpdates() {
PendingResult<Status> pendingResult = LocationServices.FusedLocationApi.requestLocationUpdates(
mGoogleApiClient, mLocationRequest, this);
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
Log.d(TAG, "Connection failed: " + connectionResult.toString());
}
@Override
public void onLocationChanged(Location location) {
Log.d(TAG, "Firing onLocationChanged");
mCurrentLocation = location;
if (loc.size() > 0)
if (mCurrentLocation.getTime() <= loc.get(loc.size() - 1).getTime()) return;
loc.add(mCurrentLocation);
updateUI();
addMarker(loc.get(0));
Log.d(TAG, loc.size() + " " + marker.size());
Log.d("distance", changeDistance + " ");
for (int i = 0; i < loc.size(); i++) {
if (mCurrentLocation != loc.get(i)) {
if (loc.size() == 1 || loc.size() == 0) {
distance = getDistance(loc.get(0).getLatitude(), loc.get(0).getLongitude(), mCurrentLocation.getLatitude(), mCurrentLocation.getLongitude());
} else {
mGoogleMap.addPolyline(new PolylineOptions().geodesic(true)
.add(new LatLng(loc.get(i).getLatitude(), loc.get(i).getLongitude()), new LatLng(loc.get(i + 1).getLatitude(), loc.get(i + 1).getLongitude()))
.width(3)
.color(Color.BLUE));
Log.d("distance1", distance + " i " + i);
distance = getDistance(loc.get(i).getLatitude(), loc.get(i).getLongitude(), loc.get(i + 1).getLatitude(), loc.get(i + 1).getLongitude());
if (marker.size() > 2)
remove(i);
}
}
}
addMarker(loc.get(loc.size() - 1));
Log.d("distance new", distance + " i ");
changeDistance = changeDistance + distance;
Log.d("changeDistance ", changeDistance + "");
mLastUpdateTime = DateFormat.getTimeInstance().format(new Date());
updateUI();
}
private void remove(int i) {
mapMarker = marker.get(i);
mapMarker.remove();
marker.remove(mapMarker);
}
private void updateUI() {
Log.d(TAG, "UI update initiated");
if (null != mCurrentLocation) {
float distnceInKm = changeDistance / 1000;
Log.d("distance km", distnceInKm + "");
String lat = String.valueOf(mCurrentLocation.getLatitude());
String lng = String.valueOf(mCurrentLocation.getLongitude());
latitude = mCurrentLocation.getLatitude();
longitude = mCurrentLocation.getLongitude();
tvText.setText("At Time: " + mLastUpdateTime + "\n" +
"Latitude: " + lat + "\n" +
"Longitude: " + lng + "\n" +
"Accuracy: " + mCurrentLocation.getAccuracy() + "\n" +
"Provider: " + mCurrentLocation.getProvider() + "\n" +
"Distance " + distnceInKm + " km");
} else {
tvText.setText("location is null ");
Log.d(TAG, "location is null ");
}
}
public float getDistance(double lat1, double lon1, double lat2, double lon2) {
android.location.Location homeLocation = new android.location.Location("");
homeLocation.setLatitude(lat1);
homeLocation.setLongitude(lon1);
android.location.Location targetLocation = new android.location.Location("");
targetLocation.setLatitude(lat2);
targetLocation.setLongitude(lon2);
return targetLocation.distanceTo(homeLocation);
}
}
答案 0 :(得分：2)
在这里你可以调用你的线程asynctask -
new AsyncCaller().execute();
现在在doInBackground(Void... params)方法
private class AsyncCaller extends AsyncTask<Void, Void, Void>
{
ProgressDialog pdLoading = new ProgressDialog(AsyncExample.this);
@Override
protected void onPreExecute() {
super.onPreExecute();
//this method will be running on UI thread
pdLoading.setMessage("\tLoading...");
pdLoading.show();
}
@Override
protected Void doInBackground(Void... params) {
//this method will be running on background thread so don't update UI frome here
//do your long running http tasks here like gps operations of yours,you dont want to pass argument and u can access the parent class' variable url over here
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
//this method will be running on UI thread
pdLoading.dismiss();
}
}
}