GPS程序適用於JellyBean和KitKat，但不適用於Gingerbread

Question

我已經寫了一個應用程序來查找GPS坐標。 該程序在Android 4.3和4.4.2上完全可以正常運行，但是由於某些原因在2.3.4和2.3.6上不起作用。 GPS甚至沒有打開。 要使其與舊版API兼容還需要做些其他事情嗎？ 我在清單中包含以下權限：

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_LOCATION_EXTRA_COMMANDS" />
<uses-permission android:name="android.permission.ACCESS_GPS" /> 

這是代碼：

package com.hari.gps;

import android.app.Activity;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.telephony.SmsManager;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity implements LocationListener {
private TextView latituteField;
private TextView longitudeField;
public static Context mContext;

public static Context getContext() {
    return mContext;
}

public void setContext(Context mContext) {
    MainActivity.mContext = mContext;
}
private LocationManager locationManager;
private String provider;
public static float lat, lng;
public static TextView t3, t4, t5, t6;
// SMSReceiver s;
/** Called when the activity is first created. */

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    latituteField = (TextView) findViewById(R.id.text1);
    longitudeField = (TextView) findViewById(R.id.text2);
    // Get the location manager
    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    // Define the criteria how to select the locatioin provider -> use
    // default
    Criteria criteria = new Criteria();
    provider = locationManager.getBestProvider(criteria, false);
    Location location = locationManager.getLastKnownLocation(provider);

    // Initialize the location fields
    if (location != null) {
        System.out.println("Provider " + provider + " has been selected.");
        onLocationChanged(location);
    } else {
        latituteField.setText("Location not available");
        longitudeField.setText("Location not available");
    }

}

/* Request updates at startup */
@Override
protected void onResume() {
    super.onResume();
    // s.onReceive(getApplicationContext(), getIntent());
    //
    // t3.setText(s.messageReceived);
    locationManager.requestLocationUpdates(provider, 400, 1, this);
}

public void msg(View view) {
    EditText e1 = (EditText) findViewById(R.id.edit);
    String phoneno = "8056371433";
    String s = e1.getText().toString();
    String message, m1, m2;
    t3 = (TextView) findViewById(R.id.text3);
    t4 = (TextView) findViewById(R.id.text4);
    t5 = (TextView) findViewById(R.id.text5);
    t6 = (TextView) findViewById(R.id.text6);
    m1 = String.valueOf(lat);
    m2 = String.valueOf(lng);
    message = m1 + " " + m2;
    if (e1.getText().length() == 0)
        sendSMS(phoneno, message);
    else
        sendSMS(s, message);
}

private void sendSMS(String phoneNumber, String message) {
    String SENT = "SMS_SENT";
    String DELIVERED = "SMS_DELIVERED";

    PendingIntent sentPI = PendingIntent.getBroadcast(MainActivity.this, 0,
            new Intent(SENT), 0);

    PendingIntent deliveredPI = PendingIntent.getBroadcast(
            MainActivity.this, 0, new Intent(DELIVERED), 0);
    SmsManager sms = SmsManager.getDefault();
    sms.sendTextMessage(phoneNumber, null, message, sentPI, deliveredPI);
}

/* Remove the locationlistener updates when Activity is paused */
@Override
protected void onPause() {
    super.onPause();
    locationManager.removeUpdates(this);
}

@Override
public void onLocationChanged(Location location) {
    boolean flag1 = true, flag2 = true;
    lat = (float) (location.getLatitude());
    lng = (float) (location.getLongitude());
    if (lng < 0) {
        lng = -lng;
        flag1 = false;
    }
    if (lat < 0) {
        lat = -lat;
        flag2 = false;
    }

    if (flag2)
        latituteField.setText("Latitude = " + lat + " N" + "\n");
    else
        latituteField.setText("Latitude = " + lat + " S" + "\n");

    if (flag1)
        longitudeField.setText("Longitude = " + lng + " E");
    else
        longitudeField.setText("Longitude = " + lng + " W");
    // deg = Math.abs((int) lat);
    // min = (int) ((lat - (float) deg) * 60.0);
    // sec = (int) ((((lat - (float) deg) * 60) - min) * 60);
    // if (flag2)
    // latituteField.setText("Latitude    =  " +String.valueOf(deg) + "° "
    // + String.valueOf(min) + "\' " + String.valueOf(sec) + "\""
    // + 'N'+"\n");
    // else
    // latituteField.setText("Latitude    =  " +String.valueOf(deg) + "° "
    // + String.valueOf(min) + "\' " + String.valueOf(sec) + "\""
    // + 'S'+"\n");
    // deg = Math.abs((int) lng);
    // min = (int) ((lng - (float) deg) * 60.0);
    // sec = (int) ((((lng - (float) deg) * 60) - min) * 60);
    // if (flag1)
    // longitudeField.setText("Longitude = " + String.valueOf(deg) + "° "
    // + String.valueOf(min) + "\' " + String.valueOf(sec) + "\""
    // + 'E');
    // else
    // longitudeField.setText("Longitude = " + String.valueOf(deg) + "° "
    // + String.valueOf(min) + "\' " + String.valueOf(sec) + "\""
    // + 'W');
}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
    // TODO Auto-generated method stub

}

@Override
public void onProviderEnabled(String provider) {
    Toast.makeText(this, "Enabled new provider " + provider,
            Toast.LENGTH_SHORT).show();

}

@Override
public void onProviderDisabled(String provider) {
    Toast.makeText(this, "Disabled provider " + provider,
            Toast.LENGTH_SHORT).show();
}

}

Answer 1

我不得不添加requestlocationupdates（）以使其正常工作，奇怪的是我沒有在Jellybean和KitKat上使用上述功能就獲取了GPS坐標。 所以修改后的代碼是：

Criteria criteria = new Criteria();
Location location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
provider = locationManager.getBestProvider(criteria, true);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this);

Answer 2

//start public class MainActivity extends FragmentActivity implements GooglePlayServicesClient.ConnectionCallbacks,GooglePlayServicesClient.OnConnectionFailedListener,com.google.android.gms.location.LocationListener,com.google.android.gms.maps.GoogleMap.OnMapClickListener,OnMapLongClickListener,OnMarkerClickListener,GoogleMap.OnInfoWindowClickListener { // Update interval in milliseconds for location services private static final long UPDATE_INTERVAL = 5000; // Fastest update interval in milliseconds for location services private static final long FASTEST_INTERVAL = 1000; // Google Play diagnostics constant private final static int CONNECTION_FAILURE_RESOLUTION_REQUEST = 9000; // Speed threshold for orienting map in direction of motion (m/s) private static final double SPEED_THRESH = 1; private static final String TAG = "Mapper"; private LocationClient locationClient; private Location currentLocation; private double currentLat; private double currentLon; private GoogleMap map; private LatLng map_center; private int zoomOffset = 5; private float currentZoom; private float bearing; private float speed; private float acc; private Circle localCircle; private double lon; private double lat; static final int numberOptions = 10; String [] optionArray = new String[numberOptions]; // Define an object that holds accuracy and frequency parameters LocationRequest locationRequest; // Set up shared preferences to persist data. We will use it later // to save the current zoom level if user leaves this activity, and // restore it when she returns. SharedPreferences prefs; SharedPreferences.Editor prefsEditor; @SuppressLint("NewApi") @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // Get a handle to the Map Fragment // map = ((MapFragment) getFragmentManager() // .findFragmentById(R.id.mapme_map)).getMap(); map=((SupportMapFragment) getSupportFragmentManager() .findFragmentById(R.id.mapme_map)).getMap(); if(map != null){ // Set the initial zoom level of the map currentZoom = map.getMaxZoomLevel()-zoomOffset; // Add a click listener to the map map.setOnMapClickListener(this); // Add a long-press listener to the map map.setOnMapLongClickListener(this); // Add Marker click listener to the map map.setOnMarkerClickListener(this); // Add marker info window click listener map.setOnInfoWindowClickListener(this); } else { Toast.makeText(this, "error", Toast.LENGTH_LONG).show(); } /* Create new location client. The first 'this' in args is the present * context; the next two 'this' args indicate that this class will handle * callbacks associated with connection and connection errors, respectively * (see the onConnected, onDisconnected, and onConnectionError callbacks below). * You cannot use the location client until the onConnected callback * fires, indicating a valid connection. At that point you can access location * services such as present position and location updates. */ locationClient = new LocationClient(this, this, this); // Create the LocationRequest object locationRequest = LocationRequest.create(); // Set request for high accuracy locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY); // Set update interval locationRequest.setInterval(UPDATE_INTERVAL); // Set fastest update interval that we can accept locationRequest.setFastestInterval(FASTEST_INTERVAL); // Get a shared preferences prefs = getSharedPreferences("SharedPreferences", Context.MODE_PRIVATE); // Get a SharedPreferences editor prefsEditor = prefs.edit(); // Keep screen on while this map location tracking activity is running getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); } // Following two methods display and handle the top bar options menu for maps // Save the current zoom level when going into the background @Override protected void onPause() { // Store the current map zoom level if(map != null){ currentZoom = map.getCameraPosition().zoom; prefsEditor.putFloat("KEY_ZOOM",currentZoom); prefsEditor.commit(); } super.onPause(); Log.i(TAG,"onPause: Zoom="+currentZoom); } @Override protected void onResume() { super.onResume(); // Restore previous zoom level (default to max zoom level if // no prefs stored) if (prefs.contains("KEY_ZOOM") && map != null){ currentZoom = prefs.getFloat("KEY_ZOOM", map.getMaxZoomLevel()); } Log.i(TAG,"onResume: Zoom="+currentZoom); // Keep screen on while this map location tracking activity is running getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); } /* The following two lifecycle methods conserve resources by ensuring that * location services are connected when the map is visible and disconnected when * it is not. */ // Called by system when Activity becomes visible, so connect location client. @Override protected void onStart() { super.onStart(); locationClient.connect(); } // Called by system when Activity is no longer visible, so disconnect location // client, which invalidates it. @Override protected void onStop() { // If the client is connected, remove location updates and disconnect if (locationClient.isConnected()) { locationClient.removeLocationUpdates(this); } locationClient.disconnect(); // Turn off the screen-always-on request getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); super.onStop(); } }