最近我正在学习如何使用gps和marker来查明我当前的位置。现在我尝试修改，以便代码能够跟踪我当前的位置并计算我在我的位置更新时的总行进距离。一开始，它可以找到。但是2-3分钟后，我的应用程序开始挂起并提示我强制关闭，因为我的应用程序没有响应。
以下是我的代码：
public class WhereAmINowActivity extends Activity {
//declaration of variables
public void getPrevActivityValue(){
Intent intent = getIntent();
// get the value from prev activity
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.start_distance);
getPrevActivityValue();
btnStart = (Button)findViewById(R.id.btnStart);
btnStop = (Button)findViewById(R.id.btnStop);
distance = (TextView)findViewById(R.id.distance);
locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setAltitudeRequired(false);
criteria.setBearingRequired(false);
criteria.setCostAllowed(true);
criteria.setPowerRequirement(Criteria.POWER_LOW);
provider = locationManager.getBestProvider(criteria, true);
location = locationManager.getLastKnownLocation(provider);
updateWithNewLocation(location);
locationManager.requestLocationUpdates(provider, TWO_MIN, HUNDRED_METERS ,locationListener);
addListenerOnBtnStart();
addListenerOnBtnStop();
}
public void addListenerOnBtnStart(){
btnStart.setOnClickListener(new View.OnClickListener(){
public void onClick(View paramAnonymousView){
if(!startPressed){
// Initialize the variables of current and old location coordinates
}
catch (Exception e){
e.printStackTrace();
}
}
else{
// Do nothing
}
}
});
}
public void addListenerOnBtnStop(){
btnStop.setOnClickListener(new View.OnClickListener(){
public void onClick(View paramAnonymousView){
try{
if(connected to internet is true)
// Do something here
}
else{
// prompt message to notify user connectivity is not available
}
}
catch (Exception e){
e.printStackTrace();
}
}
});
}
private final LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
updateWithNewLocation(location);
}
public void onProviderDisabled(String provider){
updateWithNewLocation(null);
}
public void onProviderEnabled(String provider){ }
public void onStatusChanged(String provider, int status,
Bundle extras){ }
};
private void updateWithNewLocation(Location location) {
// Update the current location, old coordinates and get the address
}
}
使用getIntent（）从前一个活动传递了一些值。
任何人都可以帮我弄清楚我错误地做了哪一部分？
增加： 我删除了叠加层并仅在位置监听器上进行了测试。 我发现当它运行大约2-3分钟时，我的应用程序的界面将不会响应我按下的内容（因为我声明了两个按钮 - 启动和停止）。当我按下停止按钮时，没有任何反应，然后向我提示强制关闭消息。这是我做错了吗？我应该如何纠正它，以便当我使用GPS行走时它可以像正常距离计算一样工作？
答案 0 :(得分：0)
我在开源Gps Tracker中解决了这个问题。完整的Android项目在这里：
https://github.com/nickfox/GpsTracker/tree/master/phoneClients/android
以及进行跟踪的课程如下。您想要查看名为totalDistanceInMeters的变量。
package com.websmithing.gpstracker;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.location.Location;
import android.os.Bundle;
import android.os.IBinder;
import android.util.Log;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesClient;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.location.LocationClient;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.loopj.android.http.AsyncHttpResponseHandler;
import com.loopj.android.http.RequestParams;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;
public class LocationService extends Service implements
GooglePlayServicesClient.ConnectionCallbacks,
GooglePlayServicesClient.OnConnectionFailedListener,
LocationListener {
private static final String TAG = "LocationService";
// use the websmithing defaultUploadWebsite for testing and then check your
// location with your browser here: https://www.websmithing.com/gpstracker/displaymap.php
private String defaultUploadWebsite;
private boolean currentlyProcessingLocation = false;
private LocationRequest locationRequest;
private LocationClient locationClient;
@Override
public void onCreate() {
super.onCreate();
defaultUploadWebsite = getString(R.string.default_upload_website);
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// if we are currently trying to get a location and the alarm manager has called this again,
// no need to start processing a new location.
if (!currentlyProcessingLocation) {
currentlyProcessingLocation = true;
startTracking();
}
return START_NOT_STICKY;
}
private void startTracking() {
Log.d(TAG, "startTracking");
if (GooglePlayServicesUtil.isGooglePlayServicesAvailable(this) == ConnectionResult.SUCCESS) {
locationClient = new LocationClient(this,this,this);
if (!locationClient.isConnected() || !locationClient.isConnecting()) {
locationClient.connect();
}
} else {
Log.e(TAG, "unable to connect to google play services.");
}
}
protected void sendLocationDataToWebsite(Location location) {
// formatted for mysql datetime format
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
dateFormat.setTimeZone(TimeZone.getDefault());
Date date = new Date(location.getTime());
SharedPreferences sharedPreferences = this.getSharedPreferences("com.websmithing.gpstracker.prefs", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
float totalDistanceInMeters = sharedPreferences.getFloat("totalDistanceInMeters", 0f);
boolean firstTimeGettingPosition = sharedPreferences.getBoolean("firstTimeGettingPosition", true);
if (firstTimeGettingPosition) {
editor.putBoolean("firstTimeGettingPosition", false);
} else {
Location previousLocation = new Location("");
previousLocation.setLatitude(sharedPreferences.getFloat("previousLatitude", 0f));
previousLocation.setLongitude(sharedPreferences.getFloat("previousLongitude", 0f));
float distance = location.distanceTo(previousLocation);
totalDistanceInMeters += distance;
editor.putFloat("totalDistanceInMeters", totalDistanceInMeters);
}
editor.putFloat("previousLatitude", (float)location.getLatitude());
editor.putFloat("previousLongitude", (float)location.getLongitude());
editor.apply();
final RequestParams requestParams = new RequestParams();
requestParams.put("latitude", Double.toString(location.getLatitude()));
requestParams.put("longitude", Double.toString(location.getLongitude()));
Double speedInMilesPerHour = location.getSpeed()* 2.2369;
requestParams.put("speed", Integer.toString(speedInMilesPerHour.intValue()));
try {
requestParams.put("date", URLEncoder.encode(dateFormat.format(date), "UTF-8"));
} catch (UnsupportedEncodingException e) {}
requestParams.put("locationmethod", location.getProvider());
if (totalDistanceInMeters > 0) {
requestParams.put("distance", String.format("%.1f", totalDistanceInMeters / 1609)); // in miles,
} else {
requestParams.put("distance", "0.0"); // in miles
}
requestParams.put("username", sharedPreferences.getString("userName", ""));
requestParams.put("phonenumber", sharedPreferences.getString("appID", "")); // uuid
requestParams.put("sessionid", sharedPreferences.getString("sessionID", "")); // uuid
Double accuracyInFeet = location.getAccuracy()* 3.28;
requestParams.put("accuracy", Integer.toString(accuracyInFeet.intValue()));
Double altitudeInFeet = location.getAltitude() * 3.28;
requestParams.put("extrainfo", Integer.toString(altitudeInFeet.intValue()));
requestParams.put("eventtype", "android");
Float direction = location.getBearing();
requestParams.put("direction", Integer.toString(direction.intValue()));
final String uploadWebsite = sharedPreferences.getString("defaultUploadWebsite", defaultUploadWebsite);
LoopjHttpClient.get(uploadWebsite, requestParams, new AsyncHttpResponseHandler() {
@Override
public void onSuccess(int statusCode, org.apache.http.Header[] headers, byte[] responseBody) {
LoopjHttpClient.debugLoopJ(TAG, "sendLocationDataToWebsite - success", uploadWebsite, requestParams, responseBody, headers, statusCode, null);
stopSelf();
}
@Override
public void onFailure(int statusCode, org.apache.http.Header[] headers, byte[] errorResponse, Throwable e) {
LoopjHttpClient.debugLoopJ(TAG, "sendLocationDataToWebsite - failure", uploadWebsite, requestParams, errorResponse, headers, statusCode, e);
stopSelf();
}
});
}
@Override
public void onDestroy() {
super.onDestroy();
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onLocationChanged(Location location) {
if (location != null) {
Log.e(TAG, "position: " + location.getLatitude() + ", " + location.getLongitude() + " accuracy: " + location.getAccuracy());
// we have our desired accuracy of 500 meters so lets quit this service,
// onDestroy will be called and stop our location uodates
if (location.getAccuracy() < 500.0f) {
stopLocationUpdates();
sendLocationDataToWebsite(location);
}
}
}
private void stopLocationUpdates() {
if (locationClient != null && locationClient.isConnected()) {
locationClient.removeLocationUpdates(this);
locationClient.disconnect();
}
}
/**
* 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) {
Log.d(TAG, "onConnected");
locationRequest = LocationRequest.create();
locationRequest.setInterval(1000); // milliseconds
locationRequest.setFastestInterval(1000); // the fastest rate in milliseconds at which your app can handle location updates
locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
locationClient.requestLocationUpdates(locationRequest, this);
}
/**
* Called by Location Services if the connection to the
* location client drops because of an error.
*/
@Override
public void onDisconnected() {
Log.e(TAG, "onDisconnected");
stopLocationUpdates();
stopSelf();
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
Log.e(TAG, "onConnectionFailed");
stopLocationUpdates();
stopSelf();
}
}