使用电池塔以较少的电池和高精度获取离线模式下的当前位置

时间:2013-12-12 11:26:22

标签: java android gps currentlocation location-client

我按照thisthis链接获取了当前位置信息。这里没有使用Wi-Fi和GPS获取当前位置但是当位置改变时它没有更新,如果我在GPS / Wi-Fi上它开始更新。在这里,我希望仅基于具有低电池消耗和高精度的电池塔进行更新。

这是我的代码

MainActivity.java

package com.example.offline;

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 android.content.IntentSender;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.Dialog;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.support.v4.app.DialogFragment;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.view.View;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

import java.io.IOException;
import java.util.List;
import java.util.Locale;

    public class MainActivity extends FragmentActivity implements
        LocationListener,
        GooglePlayServicesClient.ConnectionCallbacks,
        GooglePlayServicesClient.OnConnectionFailedListener {

    // A request to connect to Location Services
    private LocationRequest mLocationRequest;

    // Stores the current instantiation of the location client in this object
    private LocationClient mLocationClient;

    // Handles to UI widgets
    private TextView mLatLng;
    private TextView mAddress;
    private ProgressBar mActivityIndicator;
    private TextView mConnectionState;
    private TextView mConnectionStatus;

    // Handle to SharedPreferences for this app
    SharedPreferences mPrefs;

    // Handle to a SharedPreferences editor
    SharedPreferences.Editor mEditor;
    boolean mUpdatesRequested = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Get handles to the UI view objects
        mLatLng = (TextView) findViewById(R.id.lat_lng);
        mAddress = (TextView) findViewById(R.id.address);
//        mActivityIndicator = (ProgressBar) findViewById(R.id.address_progress);
        mConnectionState = (TextView) findViewById(R.id.text_connection_state);
        mConnectionStatus = (TextView) findViewById(R.id.text_connection_status);

        // Create a new global location parameters object
        mLocationRequest = LocationRequest.create();

        mLocationRequest.setInterval(LocationUtils.UPDATE_INTERVAL_IN_MILLISECONDS);

        // Use high accuracy
        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

        // Set the interval ceiling to one minute
        mLocationRequest.setFastestInterval(LocationUtils.FAST_INTERVAL_CEILING_IN_MILLISECONDS);

        // Note that location updates are off until the user turns them on
        mUpdatesRequested = false;

        // Open Shared Preferences
        mPrefs = getSharedPreferences(LocationUtils.SHARED_PREFERENCES, Context.MODE_PRIVATE);

        // Get an editor
        mEditor = mPrefs.edit();

        mLocationClient = new LocationClient(this, this, this);

    }

    @Override
    public void onStop() {

        // If the client is connected
        if (mLocationClient.isConnected()) {
            stopPeriodicUpdates();
        }

        // After disconnect() is called, the client is considered "dead".
        mLocationClient.disconnect();

        super.onStop();
    }

    @Override
    public void onPause() {

        // Save the current setting for updates
        mEditor.putBoolean(LocationUtils.KEY_UPDATES_REQUESTED, mUpdatesRequested);
        mEditor.commit();

        super.onPause();
    }

    @Override
    public void onStart() {

        super.onStart();

        /*
         * Connect the client. Don't re-start any requests here;
         * instead, wait for onResume()
         */
        mLocationClient.connect();

    }

    @Override
    public void onResume() {
        super.onResume();

        // If the app already has a setting for getting location updates, get it
        if (mPrefs.contains(LocationUtils.KEY_UPDATES_REQUESTED)) {
            mUpdatesRequested = mPrefs.getBoolean(LocationUtils.KEY_UPDATES_REQUESTED, false);

        // Otherwise, turn off location updates until requested
        } else {
            mEditor.putBoolean(LocationUtils.KEY_UPDATES_REQUESTED, false);
            mEditor.commit();
        }

    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent intent) {

        // Choose what to do based on the request code
        switch (requestCode) {

            // If the request code matches the code sent in onConnectionFailed
            case LocationUtils.CONNECTION_FAILURE_RESOLUTION_REQUEST :

                switch (resultCode) {
                    // If Google Play services resolved the problem
                    case Activity.RESULT_OK:

                        // Log the result
                        Log.d(LocationUtils.APPTAG, getString(R.string.resolved));

                        // Display the result
                        mConnectionState.setText(R.string.connected);
                        mConnectionStatus.setText(R.string.resolved);
                    break;

                    // If any other result was returned by Google Play services
                    default:
                        // Log the result
                        Log.d(LocationUtils.APPTAG, getString(R.string.no_resolution));

                        // Display the result
                        mConnectionState.setText(R.string.disconnected);
                        mConnectionStatus.setText(R.string.no_resolution);

                    break;
                }

            // If any other request code was received
            default:
               // Report that this Activity received an unknown requestCode
               Log.d(LocationUtils.APPTAG,
                       getString(R.string.unknown_activity_request_code, requestCode));

               break;
        }
    }


    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) {
            // In debug mode, log the status
            Log.d(LocationUtils.APPTAG, getString(R.string.play_services_available));

            // Continue
            return true;
        // Google Play services was not available for some reason
        } else {
            // Display an error dialog
            Dialog dialog = GooglePlayServicesUtil.getErrorDialog(resultCode, this, 0);
            if (dialog != null) {
                ErrorDialogFragment errorFragment = new ErrorDialogFragment();
                errorFragment.setDialog(dialog);
                errorFragment.show(getSupportFragmentManager(), LocationUtils.APPTAG);
            }
            return false;
        }
    }

    public void getLocation(View v) {

        // If Google Play Services is available
        if (servicesConnected()) {

            // Get the current location
            Location currentLocation = mLocationClient.getLastLocation();

            // Display the current location in the UI
            mLatLng.setText(LocationUtils.getLatLng(this, currentLocation));
        }
    }

    // For Eclipse with ADT, suppress warnings about Geocoder.isPresent()
    @SuppressLint("NewApi")
    public void getAddress(View v) {

        // In Gingerbread and later, use Geocoder.isPresent() to see if a geocoder is available.
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD && !Geocoder.isPresent()) {
            // No geocoder is present. Issue an error message
            Toast.makeText(this, R.string.no_geocoder_available, Toast.LENGTH_LONG).show();
            return;
        }

        if (servicesConnected()) {

            // Get the current location
            Location currentLocation = mLocationClient.getLastLocation();

            // Turn the indefinite activity indicator on
            mActivityIndicator.setVisibility(View.VISIBLE);

            // Start the background task
            (new MainActivity.GetAddressTask(this)).execute(currentLocation);
        }
    }

    public void startUpdates(View v) {
        mUpdatesRequested = true;

        if (servicesConnected()) {
            startPeriodicUpdates();
        }
    }

    public void stopUpdates(View v) {
        mUpdatesRequested = false;

        if (servicesConnected()) {
            stopPeriodicUpdates();
        }
    }


    @Override
    public void onConnected(Bundle bundle) {
        mConnectionStatus.setText(R.string.connected);

        if (mUpdatesRequested) {
            startPeriodicUpdates();
        }
    }

    @Override
    public void onDisconnected() {
        mConnectionStatus.setText(R.string.disconnected);
    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {

        if (connectionResult.hasResolution()) {
            try {

                // Start an Activity that tries to resolve the error
                connectionResult.startResolutionForResult(
                        this,
                        LocationUtils.CONNECTION_FAILURE_RESOLUTION_REQUEST);



            } catch (IntentSender.SendIntentException e) {

                // Log the error
                e.printStackTrace();
            }
        } else {

            // If no resolution is available, display a dialog to the user with the error.
            showErrorDialog(connectionResult.getErrorCode());
        }
    }

    @Override
    public void onLocationChanged(Location location) {

        // Report to the UI that the location was updated
        mConnectionStatus.setText(R.string.location_updated);

        // In the UI, set the latitude and longitude to the value received
        mLatLng.setText(LocationUtils.getLatLng(this, location));
    }

    private void startPeriodicUpdates() {

        mLocationClient.requestLocationUpdates(mLocationRequest, this);
        mConnectionState.setText(R.string.location_requested);
    }

    private void stopPeriodicUpdates() {
        mLocationClient.removeLocationUpdates(this);
        mConnectionState.setText(R.string.location_updates_stopped);
    }


    protected class GetAddressTask extends AsyncTask<Location, Void, String> {

        // Store the context passed to the AsyncTask when the system instantiates it.
        Context localContext;

        // Constructor called by the system to instantiate the task
        public GetAddressTask(Context context) {

            // Required by the semantics of AsyncTask
            super();

            // Set a Context for the background task
            localContext = context;
        }


        @Override
        protected String doInBackground(Location... params) {

            Geocoder geocoder = new Geocoder(localContext, Locale.getDefault());

            // Get the current location from the input parameter list
            Location location = params[0];

            // Create a list to contain the result address
            List <Address> addresses = null;

            // Try to get an address for the current location. Catch IO or network problems.
            try {

                 addresses = geocoder.getFromLocation(location.getLatitude(),
                    location.getLongitude(), 1
                );

                // Catch network or other I/O problems.
                } catch (IOException exception1) {

                    // Log an error and return an error message
                    Log.e(LocationUtils.APPTAG, getString(R.string.IO_Exception_getFromLocation));

                    // print the stack trace
                    exception1.printStackTrace();

                    // Return an error message
                    return (getString(R.string.IO_Exception_getFromLocation));

                // Catch incorrect latitude or longitude values
                } catch (IllegalArgumentException exception2) {

                    // Construct a message containing the invalid arguments
                    String errorString = getString(
                            R.string.illegal_argument_exception,
                            location.getLatitude(),
                            location.getLongitude()
                    );
                    // Log the error and print the stack trace
                    Log.e(LocationUtils.APPTAG, errorString);
                    exception2.printStackTrace();

                    //
                    return errorString;
                }
                // If the reverse geocode returned an address
                if (addresses != null && addresses.size() > 0) {

                    // Get the first address
                    Address address = addresses.get(0);

                    // Format the first line of address
                    String addressText = getString(R.string.address_output_string,

                            // If there's a street address, add it
                            address.getMaxAddressLineIndex() > 0 ?
                                    address.getAddressLine(0) : "",

                            // Locality is usually a city
                            address.getLocality(),

                            // The country of the address
                            address.getCountryName()
                    );

                    // Return the text
                    return addressText;

                // If there aren't any addresses, post a message
                } else {
                  return getString(R.string.no_address_found);
                }
        }

        @Override
        protected void onPostExecute(String address) {

            // Turn off the progress bar
            mActivityIndicator.setVisibility(View.GONE);

            // Set the address in the UI
            mAddress.setText(address);
        }
    }

   private void showErrorDialog(int errorCode) {

        // Get the error dialog from Google Play services
        Dialog errorDialog = GooglePlayServicesUtil.getErrorDialog(
            errorCode,
            this,
            LocationUtils.CONNECTION_FAILURE_RESOLUTION_REQUEST);

        // If Google Play services can provide an error dialog
        if (errorDialog != null) {

            // Create a new DialogFragment in which to show the error dialog
            ErrorDialogFragment errorFragment = new ErrorDialogFragment();

            // Set the dialog in the DialogFragment
            errorFragment.setDialog(errorDialog);

            // Show the error dialog in the DialogFragment
            errorFragment.show(getSupportFragmentManager(), LocationUtils.APPTAG);
        }
    }

    ublic static class ErrorDialogFragment extends DialogFragment {

        // Global field to contain the error dialog
        private Dialog mDialog;

        /**
         * Default constructor. Sets the dialog field to null
         */
        public ErrorDialogFragment() {
            super();
            mDialog = null;
        }

       public void setDialog(Dialog dialog) {
            mDialog = dialog;
        }

        /*
         * This method must return a Dialog to the DialogFragment.
         */
        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            return mDialog;
        }
    }
}

LocationUtils.java

package com.example.offline;

import android.content.Context;
import android.location.Location;


/**
 * Defines app-wide constants and utilities
 */
public final class LocationUtils {

    // Debugging tag for the application
    public static final String APPTAG = "LocationSample";

    // Name of shared preferences repository that stores persistent state
    public static final String SHARED_PREFERENCES =
            "com.example.android.location.SHARED_PREFERENCES";

    // Key for storing the "updates requested" flag in shared preferences
    public static final String KEY_UPDATES_REQUESTED =
            "com.example.android.location.KEY_UPDATES_REQUESTED";

    /*
     * Define a request code to send to Google Play services
     * This code is returned in Activity.onActivityResult
     */
    public final static int CONNECTION_FAILURE_RESOLUTION_REQUEST = 9000;

    /*
     * Constants for location update parameters
     */
    // Milliseconds per second
    public static final int MILLISECONDS_PER_SECOND = 1000;

    // The update interval
    public static final int UPDATE_INTERVAL_IN_SECONDS = 5;

    // A fast interval ceiling
    public static final int FAST_CEILING_IN_SECONDS = 1;

    // Update interval in milliseconds
    public static final long UPDATE_INTERVAL_IN_MILLISECONDS =
            MILLISECONDS_PER_SECOND * UPDATE_INTERVAL_IN_SECONDS;

    // A fast ceiling of update intervals, used when the app is visible
    public static final long FAST_INTERVAL_CEILING_IN_MILLISECONDS =
            MILLISECONDS_PER_SECOND * FAST_CEILING_IN_SECONDS;

    // Create an empty string for initializing strings
    public static final String EMPTY_STRING = new String();

    /**
     * Get the latitude and longitude from the Location object returned by
     * Location Services.
     *
     * @param currentLocation A Location object containing the current location
     * @return The latitude and longitude of the current location, or null if no
     * location is available.
     */
    public static String getLatLng(Context context, Location currentLocation) {
        // If the location is valid
        if (currentLocation != null) {

            // Return the latitude and longitude as strings
            return context.getString(
                    R.string.latitude_longitude,
                    currentLocation.getLatitude(),
                    currentLocation.getLongitude());
        } else {

            // Otherwise, return the empty string
            return EMPTY_STRING;
        }
    }
}

LocationServiceErrorMessages.java

package com.example.offline;

import com.google.android.gms.common.ConnectionResult;

import android.content.Context;
import android.content.res.Resources;


/**
 * Map error codes to error messages.
 */
public class LocationServiceErrorMessages {

    // Don't allow instantiation
    private LocationServiceErrorMessages() {}

    public static String getErrorString(Context context, int errorCode) {

        // Get a handle to resources, to allow the method to retrieve messages.
        Resources mResources = context.getResources();

        // Define a string to contain the error message
        String errorString;

        // Decide which error message to get, based on the error code.
        switch (errorCode) {
            case ConnectionResult.DEVELOPER_ERROR:
                errorString = mResources.getString(R.string.connection_error_misconfigured);
                break;

            case ConnectionResult.INTERNAL_ERROR:
                errorString = mResources.getString(R.string.connection_error_internal);
                break;

            case ConnectionResult.INVALID_ACCOUNT:
                errorString = mResources.getString(R.string.connection_error_invalid_account);
                break;

            case ConnectionResult.LICENSE_CHECK_FAILED:
                errorString = mResources.getString(R.string.connection_error_license_check_failed);
                break;

            case ConnectionResult.NETWORK_ERROR:
                errorString = mResources.getString(R.string.connection_error_network);
                break;

            case ConnectionResult.RESOLUTION_REQUIRED:
                errorString = mResources.getString(R.string.connection_error_needs_resolution);
                break;

            case ConnectionResult.SERVICE_DISABLED:
                errorString = mResources.getString(R.string.connection_error_disabled);
                break;

            case ConnectionResult.SERVICE_INVALID:
                errorString = mResources.getString(R.string.connection_error_invalid);
                break;

            case ConnectionResult.SERVICE_MISSING:
                errorString = mResources.getString(R.string.connection_error_missing);
                break;

            case ConnectionResult.SERVICE_VERSION_UPDATE_REQUIRED:
                errorString = mResources.getString(R.string.connection_error_outdated);
                break;

            case ConnectionResult.SIGN_IN_REQUIRED:
                errorString = mResources.getString(
                        R.string.connection_error_sign_in_required);
                break;

            default:
                errorString = mResources.getString(R.string.connection_error_unknown);
                break;
        }

        // Return the error message
        return errorString;
    }
}

0 个答案:

没有答案