1

最近我正在学习使用 gps 和标记来确定我当前的位置。现在我尝试进行修改，以便代码能够跟踪我当前的位置，并在我的位置更新时计算我的总行驶距离。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。

下面是我的代码：

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 

        }


}

一些值是通过使用 getIntent() 从先前的活动传递的。

谁能帮我弄清楚我做错了哪一部分？

另外：我删除了覆盖并仅在位置侦听器上进行了测试。我发现当它运行大约 2-3 分钟时，我的应用程序界面不会响应我按下的内容（因为我声明了两个按钮 - 开始和停止）。当我按下停止按钮时，什么也没发生，然后提示我强制关闭消息。这是我做错的部分吗？当我使用 GPS 行走时，我应该如何更正它以便它可以像正常的距离计算一样工作？

4

1 回答 1

0

我已经在我的开源 Gps Tracker 中解决了这个确切的问题。完整的 android 项目在这里：

https://github.com/nickfox/GpsTracker/tree/master/phoneClients/android

下面是进行跟踪的类。您想查看名为 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();
    }
}
于 2015-03-18T22:55:17.107 回答